Add cache for when rollbacking on edge adding and removing

* Add AUTH system tx deltas
* Add auth data RPC and handlers
* Support multiple system deltas in a single transaction
* Added e2e test
* Bugfix: KVStore segfault after move

---------

Co-authored-by: Gareth Lloyd <gareth.lloyd@memgraph.io>

.github/workflows/daily_benchmark.yaml

@@ -16,7 +16,7 @@ jobs:
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)

.github/workflows/diff.yaml

@@ -27,7 +27,7 @@ jobs:
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)
@@ -65,7 +65,7 @@ jobs:
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)
@@ -96,7 +96,7 @@ jobs:
 
       - name: Python code analysis
         run: |
-          CHANGED_FILES=$(git diff -U0 ${{ env.BASE_BRANCH }}... --name-only)
+          CHANGED_FILES=$(git diff -U0 ${{ env.BASE_BRANCH }}... --name-only --diff-filter=d)
           for file in ${CHANGED_FILES}; do
             echo ${file}
             if [[ ${file} == *.py ]]; then
@@ -137,9 +137,9 @@ jobs:
           tar -czf code_coverage.tar.gz coverage.json html report.json summary.rmu
 
       - name: Save code coverage
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
-          name: "Code coverage"
+          name: "Code coverage(Code analysis)"
           path: tools/github/generated/code_coverage.tar.gz
 
       - name: Run clang-tidy
@@ -162,7 +162,7 @@ jobs:
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)
@@ -208,9 +208,9 @@ jobs:
           ./cppcheck_and_clang_format diff
 
       - name: Save cppcheck and clang-format errors
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
-          name: "Code coverage"
+          name: "Code coverage(Debug build)"
           path: tools/github/cppcheck_and_clang_format.txt
 
   release_build:
@@ -223,7 +223,7 @@ jobs:
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)
@@ -251,7 +251,7 @@ jobs:
           ./continuous_integration
 
       - name: Save quality assurance status
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: "GQL Behave Status"
           path: |
@@ -268,6 +268,7 @@ jobs:
           ctest -R memgraph__unit --output-on-failure -j$THREADS
 
       - name: Ensure Kafka and Pulsar are up
+        if: false
         run: |
           cd tests/e2e/streams/kafka
           docker-compose up -d
@@ -275,6 +276,7 @@ jobs:
           docker-compose up -d
 
       - name: Run e2e tests
+        if: false
         run: |
           cd tests
           ./setup.sh /opt/toolchain-v4/activate
@@ -283,7 +285,7 @@ jobs:
           ./run.sh
 
       - name: Ensure Kafka and Pulsar are down
-        if: always()
+        if: false
         run: |
           cd tests/e2e/streams/kafka
           docker-compose down
@@ -323,21 +325,68 @@ jobs:
           cpack -G DEB --config ../CPackConfig.cmake
 
       - name: Save enterprise DEB package
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: "Enterprise DEB package"
           path: build/output/memgraph*.deb
 
       - name: Save test data
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         if: always()
         with:
-          name: "Test data"
+          name: "Test data(Release build)"
           path: |
             # multiple paths could be defined
             build/logs
 
-  experimental_build:
+  experimental_build_ha:
+    name: "High availability build"
+    runs-on: [self-hosted, Linux, X64, Diff]
+    env:
+      THREADS: 24
+      MEMGRAPH_ENTERPRISE_LICENSE: ${{ secrets.MEMGRAPH_ENTERPRISE_LICENSE }}
+      MEMGRAPH_ORGANIZATION_NAME: ${{ secrets.MEMGRAPH_ORGANIZATION_NAME }}
+
+    steps:
+      - name: Set up repository
+        uses: actions/checkout@v4
+        with:
+          # Number of commits to fetch. `0` indicates all history for all
+          # branches and tags. (default: 1)
+          fetch-depth: 0
+
+      - name: Build release binaries
+        run: |
+          source /opt/toolchain-v4/activate
+          ./init
+          cd build
+          cmake -DCMAKE_BUILD_TYPE=Release -DMG_EXPERIMENTAL_HIGH_AVAILABILITY=ON ..
+          make -j$THREADS
+      - name: Run unit tests
+        run: |
+          source /opt/toolchain-v4/activate
+          cd build
+          ctest -R memgraph__unit --output-on-failure -j$THREADS
+      - name: Run e2e tests
+        if: false
+        run: |
+          cd tests
+          ./setup.sh /opt/toolchain-v4/activate
+          source ve3/bin/activate_e2e
+          cd e2e
+          ./run.sh "Coordinator"
+          ./run.sh "Client initiated failover"
+          ./run.sh "Uninitialized cluster"
+      - name: Save test data
+        uses: actions/upload-artifact@v4
+        if: always()
+        with:
+          name: "Test data(High availability build)"
+          path: |
+            # multiple paths could be defined
+            build/logs
+
+  experimental_build_mt:
     name: "MultiTenancy replication build"
     runs-on: [self-hosted, Linux, X64, Diff]
     env:
@@ -347,7 +396,7 @@ jobs:
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)
@@ -377,6 +426,7 @@ jobs:
           ctest -R memgraph__unit --output-on-failure -j$THREADS
 
       - name: Run e2e tests
+        if: false
         run: |
           cd tests
           ./setup.sh /opt/toolchain-v4/activate
@@ -393,10 +443,10 @@ jobs:
           ./run.sh "Constraints"
 
       - name: Save test data
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         if: always()
         with:
-          name: "Test data"
+          name: "Test data(MultiTenancy replication build)"
           path: |
             # multiple paths could be defined
             build/logs
@@ -412,7 +462,7 @@ jobs:
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)
@@ -429,13 +479,18 @@ jobs:
           cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo ..
           make -j$THREADS memgraph
 
+      - name: Refresh Jepsen Cluster
+        run: |
+          cd tests/jepsen
+          ./run.sh cluster-refresh
+
       - name: Run Jepsen tests
         run: |
           cd tests/jepsen
           ./run.sh test-all-individually --binary ../../build/memgraph --ignore-run-stdout-logs --ignore-run-stderr-logs
 
       - name: Save Jepsen report
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         if: ${{ always() }}
         with:
           name: "Jepsen Report"
@@ -451,7 +506,7 @@ jobs:
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)

.github/workflows/full_clang_tidy.yaml

@@ -14,7 +14,7 @@ jobs:
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)

.github/workflows/package_memgraph.yaml

@@ -42,14 +42,14 @@ jobs:
     timeout-minutes: 60
     steps:
       - name: "Set up repository"
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0 # Required because of release/get_version.py
       - name: "Build package"
         run: |
           ./release/package/run.sh package amzn-2 ${{ github.event.inputs.build_type }}
       - name: "Upload package"
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: amzn-2
           path: build/output/amzn-2/memgraph*.rpm
@@ -60,14 +60,14 @@ jobs:
     timeout-minutes: 60
     steps:
       - name: "Set up repository"
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0 # Required because of release/get_version.py
       - name: "Build package"
         run: |
           ./release/package/run.sh package centos-7 ${{ github.event.inputs.build_type }}
       - name: "Upload package"
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: centos-7
           path: build/output/centos-7/memgraph*.rpm
@@ -78,14 +78,14 @@ jobs:
     timeout-minutes: 60
     steps:
       - name: "Set up repository"
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0 # Required because of release/get_version.py
       - name: "Build package"
         run: |
           ./release/package/run.sh package centos-9 ${{ github.event.inputs.build_type }}
       - name: "Upload package"
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: centos-9
           path: build/output/centos-9/memgraph*.rpm
@@ -96,14 +96,14 @@ jobs:
     timeout-minutes: 60
     steps:
       - name: "Set up repository"
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0 # Required because of release/get_version.py
       - name: "Build package"
         run: |
           ./release/package/run.sh package debian-10 ${{ github.event.inputs.build_type }}
       - name: "Upload package"
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: debian-10
           path: build/output/debian-10/memgraph*.deb
@@ -114,14 +114,14 @@ jobs:
     timeout-minutes: 60
     steps:
       - name: "Set up repository"
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0 # Required because of release/get_version.py
       - name: "Build package"
         run: |
           ./release/package/run.sh package debian-11 ${{ github.event.inputs.build_type }}
       - name: "Upload package"
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: debian-11
           path: build/output/debian-11/memgraph*.deb
@@ -132,14 +132,14 @@ jobs:
     timeout-minutes: 120
     steps:
       - name: "Set up repository"
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0 # Required because of release/get_version.py
       - name: "Build package"
         run: |
           ./release/package/run.sh package debian-11-arm ${{ github.event.inputs.build_type }}
       - name: "Upload package"
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: debian-11-aarch64
           path: build/output/debian-11-arm/memgraph*.deb
@@ -150,14 +150,14 @@ jobs:
     timeout-minutes: 60
     steps:
       - name: "Set up repository"
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0 # Required because of release/get_version.py
       - name: "Build package"
         run: |
           ./release/package/run.sh package debian-11 ${{ github.event.inputs.build_type }} --for-platform
       - name: "Upload package"
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: debian-11-platform
           path: build/output/debian-11/memgraph*.deb
@@ -168,7 +168,7 @@ jobs:
     timeout-minutes: 60
     steps:
       - name: "Set up repository"
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0 # Required because of release/get_version.py
       - name: "Build package"
@@ -177,7 +177,7 @@ jobs:
           ./run.sh package debian-11 ${{ github.event.inputs.build_type }} --for-docker
           ./run.sh docker
       - name: "Upload package"
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: docker
           path: build/output/docker/memgraph*.tar.gz
@@ -188,14 +188,14 @@ jobs:
     timeout-minutes: 60
     steps:
       - name: "Set up repository"
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0 # Required because of release/get_version.py
       - name: "Build package"
         run: |
           ./release/package/run.sh package fedora-36 ${{ github.event.inputs.build_type }}
       - name: "Upload package"
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: fedora-36
           path: build/output/fedora-36/memgraph*.rpm
@@ -206,14 +206,14 @@ jobs:
     timeout-minutes: 60
     steps:
       - name: "Set up repository"
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0 # Required because of release/get_version.py
       - name: "Build package"
         run: |
           ./release/package/run.sh package ubuntu-18.04 ${{ github.event.inputs.build_type }}
       - name: "Upload package"
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: ubuntu-18.04
           path: build/output/ubuntu-18.04/memgraph*.deb
@@ -224,14 +224,14 @@ jobs:
     timeout-minutes: 60
     steps:
       - name: "Set up repository"
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0 # Required because of release/get_version.py
       - name: "Build package"
         run: |
           ./release/package/run.sh package ubuntu-20.04 ${{ github.event.inputs.build_type }}
       - name: "Upload package"
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: ubuntu-20.04
           path: build/output/ubuntu-20.04/memgraph*.deb
@@ -242,14 +242,14 @@ jobs:
     timeout-minutes: 60
     steps:
       - name: "Set up repository"
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0 # Required because of release/get_version.py
       - name: "Build package"
         run: |
           ./release/package/run.sh package ubuntu-22.04 ${{ github.event.inputs.build_type }}
       - name: "Upload package"
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: ubuntu-22.04
           path: build/output/ubuntu-22.04/memgraph*.deb
@@ -260,14 +260,14 @@ jobs:
     timeout-minutes: 120
     steps:
       - name: "Set up repository"
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0 # Required because of release/get_version.py
       - name: "Build package"
         run: |
           ./release/package/run.sh package ubuntu-22.04-arm ${{ github.event.inputs.build_type }}
       - name: "Upload package"
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: ubuntu-22.04-aarch64
           path: build/output/ubuntu-22.04-arm/memgraph*.deb
@@ -279,7 +279,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Download artifacts
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           # name: # if name input parameter is not provided, all artifacts are downloaded
                   # and put in directories named after each one.

.github/workflows/performance_benchmarks.yaml

@@ -14,7 +14,7 @@ jobs:
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)

.github/workflows/release_debian10.yaml

@@ -14,19 +14,21 @@ on:
   schedule:
     - cron: "0 22 * * *"
 
+env:
+  THREADS: 24
+  MEMGRAPH_ENTERPRISE_LICENSE: ${{ secrets.MEMGRAPH_ENTERPRISE_LICENSE }}
+  MEMGRAPH_ORGANIZATION_NAME: ${{ secrets.MEMGRAPH_ORGANIZATION_NAME }}
+  BUILD_TYPE: ${{ github.event.inputs.build_type || 'Release' }}
+
 jobs:
   community_build:
     name: "Community build"
     runs-on: [self-hosted, Linux, X64, Debian10]
-    env:
-      THREADS: 24
-      MEMGRAPH_ENTERPRISE_LICENSE: ${{ secrets.MEMGRAPH_ENTERPRISE_LICENSE }}
-      MEMGRAPH_ORGANIZATION_NAME: ${{ secrets.MEMGRAPH_ORGANIZATION_NAME }}
-    timeout-minutes: 960
+    timeout-minutes: 60
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)
@@ -40,10 +42,6 @@ jobs:
           # Initialize dependencies.
           ./init
 
-          # Set default build_type to Release
-          INPUT_BUILD_TYPE=${{ github.event.inputs.build_type }}
-          BUILD_TYPE=${INPUT_BUILD_TYPE:-"Release"}
-
           # Build community binaries.
           cd build
           cmake -DCMAKE_BUILD_TYPE=$BUILD_TYPE -DMG_ENTERPRISE=OFF ..
@@ -65,10 +63,11 @@ jobs:
       THREADS: 24
       MEMGRAPH_ENTERPRISE_LICENSE: ${{ secrets.MEMGRAPH_ENTERPRISE_LICENSE }}
       MEMGRAPH_ORGANIZATION_NAME: ${{ secrets.MEMGRAPH_ORGANIZATION_NAME }}
+    timeout-minutes: 60
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)
@@ -110,22 +109,19 @@ jobs:
           tar -czf code_coverage.tar.gz coverage.json html report.json summary.rmu
 
       - name: Save code coverage
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
-          name: "Code coverage"
+          name: "Code coverage(Coverage build)"
           path: tools/github/generated/code_coverage.tar.gz
 
   debug_build:
     name: "Debug build"
     runs-on: [self-hosted, Linux, X64, Debian10]
-    env:
-      THREADS: 24
-      MEMGRAPH_ENTERPRISE_LICENSE: ${{ secrets.MEMGRAPH_ENTERPRISE_LICENSE }}
-      MEMGRAPH_ORGANIZATION_NAME: ${{ secrets.MEMGRAPH_ORGANIZATION_NAME }}
+    timeout-minutes: 60
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)
@@ -157,10 +153,6 @@ jobs:
         run: |
           ./tests/drivers/run.sh
 
-      - name: Run integration tests
-        run: |
-          tests/integration/run.sh
-
       - name: Run cppcheck and clang-format
         run: |
           # Activate toolchain.
@@ -171,23 +163,49 @@ jobs:
           ./cppcheck_and_clang_format diff
 
       - name: Save cppcheck and clang-format errors
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
-          name: "Code coverage"
+          name: "Code coverage(Debug build)"
           path: tools/github/cppcheck_and_clang_format.txt
 
-  release_build:
-    name: "Release build"
-    runs-on: [self-hosted, Linux, X64, Debian10, BigMemory]
-    env:
-      THREADS: 24
-      MEMGRAPH_ENTERPRISE_LICENSE: ${{ secrets.MEMGRAPH_ENTERPRISE_LICENSE }}
-      MEMGRAPH_ORGANIZATION_NAME: ${{ secrets.MEMGRAPH_ORGANIZATION_NAME }}
-    timeout-minutes: 960
+  debug_integration_test:
+    name: "Debug integration tests"
+    runs-on: [self-hosted, Linux, X64, Debian10]
+    timeout-minutes: 60
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
+        with:
+          # Number of commits to fetch. `0` indicates all history for all
+          # branches and tags. (default: 1)
+          fetch-depth: 0
+
+      - name: Build debug binaries
+        run: |
+          # Activate toolchain.
+          source /opt/toolchain-v4/activate
+
+          # Initialize dependencies.
+          ./init
+
+          # Build debug binaries.
+          cd build
+          cmake ..
+          make -j$THREADS
+
+      - name: Run integration tests
+        run: |
+          tests/integration/run.sh
+
+  release_build:
+    name: "Release build"
+    runs-on: [self-hosted, Linux, X64, Debian10]
+    timeout-minutes: 60
+
+    steps:
+      - name: Set up repository
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)
@@ -201,10 +219,6 @@ jobs:
           # Initialize dependencies.
           ./init
 
-          # Set default build_type to Release
-          INPUT_BUILD_TYPE=${{ github.event.inputs.build_type }}
-          BUILD_TYPE=${INPUT_BUILD_TYPE:-"Release"}
-
           # Build release binaries.
           cd build
           cmake -DCMAKE_BUILD_TYPE=$BUILD_TYPE ..
@@ -226,11 +240,60 @@ jobs:
           cpack -G DEB --config ../CPackConfig.cmake
 
       - name: Save enterprise DEB package
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: "Enterprise DEB package"
           path: build/output/memgraph*.deb
 
+      - name: Run GQL Behave tests
+        run: |
+          cd tests
+          ./setup.sh /opt/toolchain-v4/activate
+          cd gql_behave
+          ./continuous_integration
+
+      - name: Save quality assurance status
+        uses: actions/upload-artifact@v4
+        with:
+          name: "GQL Behave Status"
+          path: |
+            tests/gql_behave/gql_behave_status.csv
+            tests/gql_behave/gql_behave_status.html
+
+      - name: Run unit tests
+        run: |
+          # Activate toolchain.
+          source /opt/toolchain-v4/activate
+
+          # Run unit tests.
+          cd build
+          ctest -R memgraph__unit --output-on-failure
+
+  release_benchmark_tests:
+    name: "Release Benchmark Tests"
+    runs-on: [self-hosted, Linux, X64, Debian10]
+    timeout-minutes: 60
+
+    steps:
+      - name: Set up repository
+        uses: actions/checkout@v4
+        with:
+          # Number of commits to fetch. `0` indicates all history for all
+          # branches and tags. (default: 1)
+          fetch-depth: 0
+
+      - name: Build release binaries
+        run: |
+          # Activate toolchain.
+          source /opt/toolchain-v4/activate
+          # Initialize dependencies.
+          ./init
+
+          # Build release binaries
+          cd build
+          cmake -DCMAKE_BUILD_TYPE=$BUILD_TYPE ..
+          make -j$THREADS
+
       - name: Run micro benchmark tests
         run: |
           # Activate toolchain.
@@ -257,29 +320,38 @@ jobs:
             --num-database-workers 9 --num-clients-workers 30 \
             --no-strict
 
-      - name: Run GQL Behave tests
-        run: |
-          cd tests
-          ./setup.sh /opt/toolchain-v4/activate
-          cd gql_behave
-          ./continuous_integration
+  release_e2e_test:
+    if: false
+    name: "Release End-to-end Test"
+    runs-on: [self-hosted, Linux, X64, Debian10]
+    timeout-minutes: 60
 
-      - name: Save quality assurance status
-        uses: actions/upload-artifact@v3
+    steps:
+      - name: Set up repository
+        uses: actions/checkout@v4
         with:
-          name: "GQL Behave Status"
-          path: |
-            tests/gql_behave/gql_behave_status.csv
-            tests/gql_behave/gql_behave_status.html
+          # Number of commits to fetch. `0` indicates all history for all
+          # branches and tags. (default: 1)
+          fetch-depth: 0
 
-      - name: Run unit tests
+      - name: Build release binaries
         run: |
           # Activate toolchain.
           source /opt/toolchain-v4/activate
+          # Initialize dependencies.
+          ./init
 
-          # Run unit tests.
+          # Build release binaries
           cd build
-          ctest -R memgraph__unit --output-on-failure
+          cmake -DCMAKE_BUILD_TYPE=$BUILD_TYPE ..
+          make -j$THREADS
+
+      - name: Ensure Kafka and Pulsar are up
+        run: |
+          cd tests/e2e/streams/kafka
+          docker-compose up -d
+          cd ../pulsar
+          docker-compose up -d
 
       - name: Run e2e tests
         run: |
@@ -289,6 +361,40 @@ jobs:
           cd e2e
           ./run.sh
 
+      - name: Ensure Kafka and Pulsar are down
+        if: always()
+        run: |
+          cd tests/e2e/streams/kafka
+          docker-compose down
+          cd ../pulsar
+          docker-compose down
+
+  release_durability_stress_tests:
+    name: "Release durability and stress tests"
+    runs-on: [self-hosted, Linux, X64, Debian10]
+    timeout-minutes: 60
+
+    steps:
+      - name: Set up repository
+        uses: actions/checkout@v4
+        with:
+          # Number of commits to fetch. `0` indicates all history for all
+          # branches and tags. (default: 1)
+          fetch-depth: 0
+
+      - name: Build release binaries
+        run: |
+          # Activate toolchain.
+          source /opt/toolchain-v4/activate
+
+          # Initialize dependencies.
+          ./init
+
+          # Build release binaries.
+          cd build
+          cmake -DCMAKE_BUILD_TYPE=$BUILD_TYPE ..
+          make -j$THREADS
+
       - name: Run stress test (plain)
         run: |
           cd tests/stress
@@ -299,11 +405,6 @@ jobs:
           cd tests/stress
           ./continuous_integration --use-ssl
 
-      - name: Run stress test (large)
-        run: |
-          cd tests/stress
-          ./continuous_integration --large-dataset
-
       - name: Run durability test (plain)
         run: |
           cd tests/stress
@@ -319,15 +420,11 @@ jobs:
   release_jepsen_test:
     name: "Release Jepsen Test"
     runs-on: [self-hosted, Linux, X64, Debian10, JepsenControl]
-    env:
-      THREADS: 24
-      MEMGRAPH_ENTERPRISE_LICENSE: ${{ secrets.MEMGRAPH_ENTERPRISE_LICENSE }}
-      MEMGRAPH_ORGANIZATION_NAME: ${{ secrets.MEMGRAPH_ORGANIZATION_NAME }}
     timeout-minutes: 60
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)
@@ -340,22 +437,23 @@ jobs:
           # Initialize dependencies.
           ./init
 
-          # Set default build_type to Release
-          INPUT_BUILD_TYPE=${{ github.event.inputs.build_type }}
-          BUILD_TYPE=${INPUT_BUILD_TYPE:-"Release"}
-
           # Build only memgraph release binary.
           cd build
           cmake -DCMAKE_BUILD_TYPE=$BUILD_TYPE ..
           make -j$THREADS memgraph
 
+      - name: Refresh Jepsen Cluster
+        run: |
+          cd tests/jepsen
+          ./run.sh cluster-refresh
+
       - name: Run Jepsen tests
         run: |
           cd tests/jepsen
           ./run.sh test-all-individually --binary ../../build/memgraph --ignore-run-stdout-logs --ignore-run-stderr-logs
 
       - name: Save Jepsen report
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         if: ${{ always() }}
         with:
           name: "Jepsen Report"

.github/workflows/release_docker.yaml

@@ -19,7 +19,7 @@ jobs:
       DOCKER_REPOSITORY_NAME: memgraph
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v2

.github/workflows/release_mgbench_client.yaml

@@ -20,7 +20,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v2

.github/workflows/release_ubuntu2004.yaml

@@ -14,19 +14,21 @@ on:
   schedule:
     - cron: "0 22 * * *"
 
+env:
+  THREADS: 24
+  MEMGRAPH_ENTERPRISE_LICENSE: ${{ secrets.MEMGRAPH_ENTERPRISE_LICENSE }}
+  MEMGRAPH_ORGANIZATION_NAME: ${{ secrets.MEMGRAPH_ORGANIZATION_NAME }}
+  BUILD_TYPE: ${{ github.event.inputs.build_type || 'Release' }}
+
 jobs:
   community_build:
     name: "Community build"
     runs-on: [self-hosted, Linux, X64, Ubuntu20.04]
-    env:
-      THREADS: 24
-      MEMGRAPH_ENTERPRISE_LICENSE: ${{ secrets.MEMGRAPH_ENTERPRISE_LICENSE }}
-      MEMGRAPH_ORGANIZATION_NAME: ${{ secrets.MEMGRAPH_ORGANIZATION_NAME }}
-    timeout-minutes: 960
+    timeout-minutes: 60
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)
@@ -40,10 +42,6 @@ jobs:
           # Initialize dependencies.
           ./init
 
-          # Set default build_type to Release
-          INPUT_BUILD_TYPE=${{ github.event.inputs.build_type }}
-          BUILD_TYPE=${INPUT_BUILD_TYPE:-"Release"}
-
           # Build community binaries.
           cd build
           cmake -DCMAKE_BUILD_TYPE=$BUILD_TYPE -DMG_ENTERPRISE=OFF ..
@@ -61,14 +59,11 @@ jobs:
   coverage_build:
     name: "Coverage build"
     runs-on: [self-hosted, Linux, X64, Ubuntu20.04]
-    env:
-      THREADS: 24
-      MEMGRAPH_ENTERPRISE_LICENSE: ${{ secrets.MEMGRAPH_ENTERPRISE_LICENSE }}
-      MEMGRAPH_ORGANIZATION_NAME: ${{ secrets.MEMGRAPH_ORGANIZATION_NAME }}
+    timeout-minutes: 60
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)
@@ -110,22 +105,19 @@ jobs:
           tar -czf code_coverage.tar.gz coverage.json html report.json summary.rmu
 
       - name: Save code coverage
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
-          name: "Code coverage"
+          name: "Code coverage(Coverage build)"
           path: tools/github/generated/code_coverage.tar.gz
 
   debug_build:
     name: "Debug build"
     runs-on: [self-hosted, Linux, X64, Ubuntu20.04]
-    env:
-      THREADS: 24
-      MEMGRAPH_ENTERPRISE_LICENSE: ${{ secrets.MEMGRAPH_ENTERPRISE_LICENSE }}
-      MEMGRAPH_ORGANIZATION_NAME: ${{ secrets.MEMGRAPH_ORGANIZATION_NAME }}
+    timeout-minutes: 60
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)
@@ -157,10 +149,6 @@ jobs:
         run: |
           ./tests/drivers/run.sh
 
-      - name: Run integration tests
-        run: |
-          tests/integration/run.sh
-
       - name: Run cppcheck and clang-format
         run: |
           # Activate toolchain.
@@ -171,23 +159,49 @@ jobs:
           ./cppcheck_and_clang_format diff
 
       - name: Save cppcheck and clang-format errors
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
-          name: "Code coverage"
+          name: "Code coverage(Debug build)"
           path: tools/github/cppcheck_and_clang_format.txt
 
+  debug_integration_test:
+    name: "Debug integration tests"
+    runs-on: [self-hosted, Linux, X64, Ubuntu20.04]
+    timeout-minutes: 60
+
+    steps:
+      - name: Set up repository
+        uses: actions/checkout@v4
+        with:
+          # Number of commits to fetch. `0` indicates all history for all
+          # branches and tags. (default: 1)
+          fetch-depth: 0
+
+      - name: Build debug binaries
+        run: |
+          # Activate toolchain.
+          source /opt/toolchain-v4/activate
+
+          # Initialize dependencies.
+          ./init
+
+          # Build debug binaries.
+          cd build
+          cmake ..
+          make -j$THREADS
+
+      - name: Run integration tests
+        run: |
+          tests/integration/run.sh
+
   release_build:
     name: "Release build"
     runs-on: [self-hosted, Linux, X64, Ubuntu20.04]
-    env:
-      THREADS: 24
-      MEMGRAPH_ENTERPRISE_LICENSE: ${{ secrets.MEMGRAPH_ENTERPRISE_LICENSE }}
-      MEMGRAPH_ORGANIZATION_NAME: ${{ secrets.MEMGRAPH_ORGANIZATION_NAME }}
-    timeout-minutes: 960
+    timeout-minutes: 60
 
     steps:
       - name: Set up repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Number of commits to fetch. `0` indicates all history for all
           # branches and tags. (default: 1)
@@ -201,10 +215,6 @@ jobs:
           # Initialize dependencies.
           ./init
 
-          # Set default build_type to Release
-          INPUT_BUILD_TYPE=${{ github.event.inputs.build_type }}
-          BUILD_TYPE=${INPUT_BUILD_TYPE:-"Release"}
-
           # Build release binaries.
           cd build
           cmake -DCMAKE_BUILD_TYPE=$BUILD_TYPE ..
@@ -226,11 +236,60 @@ jobs:
           cpack -G DEB --config ../CPackConfig.cmake
 
       - name: Save enterprise DEB package
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: "Enterprise DEB package"
           path: build/output/memgraph*.deb
 
+      - name: Run GQL Behave tests
+        run: |
+          cd tests
+          ./setup.sh /opt/toolchain-v4/activate
+          cd gql_behave
+          ./continuous_integration
+
+      - name: Save quality assurance status
+        uses: actions/upload-artifact@v4
+        with:
+          name: "GQL Behave Status"
+          path: |
+            tests/gql_behave/gql_behave_status.csv
+            tests/gql_behave/gql_behave_status.html
+
+      - name: Run unit tests
+        run: |
+          # Activate toolchain.
+          source /opt/toolchain-v4/activate
+
+          # Run unit tests.
+          cd build
+          ctest -R memgraph__unit --output-on-failure
+
+  release_benchmark_tests:
+    name: "Release Benchmark Tests"
+    runs-on: [self-hosted, Linux, X64, Ubuntu20.04]
+    timeout-minutes: 60
+
+    steps:
+      - name: Set up repository
+        uses: actions/checkout@v4
+        with:
+          # Number of commits to fetch. `0` indicates all history for all
+          # branches and tags. (default: 1)
+          fetch-depth: 0
+
+      - name: Build release binaries
+        run: |
+          # Activate toolchain.
+          source /opt/toolchain-v4/activate
+          # Initialize dependencies.
+          ./init
+
+          # Build release binaries
+          cd build
+          cmake -DCMAKE_BUILD_TYPE=$BUILD_TYPE ..
+          make -j$THREADS
+
       - name: Run micro benchmark tests
         run: |
           # Activate toolchain.
@@ -257,29 +316,38 @@ jobs:
             --num-database-workers 9 --num-clients-workers 30 \
             --no-strict
 
-      - name: Run GQL Behave tests
-        run: |
-          cd tests
-          ./setup.sh /opt/toolchain-v4/activate
-          cd gql_behave
-          ./continuous_integration
+  release_e2e_test:
+    if: false
+    name: "Release End-to-end Test"
+    runs-on: [self-hosted, Linux, X64, Ubuntu20.04]
+    timeout-minutes: 60
 
-      - name: Save quality assurance status
-        uses: actions/upload-artifact@v3
+    steps:
+      - name: Set up repository
+        uses: actions/checkout@v4
         with:
-          name: "GQL Behave Status"
-          path: |
-            tests/gql_behave/gql_behave_status.csv
-            tests/gql_behave/gql_behave_status.html
+          # Number of commits to fetch. `0` indicates all history for all
+          # branches and tags. (default: 1)
+          fetch-depth: 0
 
-      - name: Run unit tests
+      - name: Build release binaries
         run: |
           # Activate toolchain.
           source /opt/toolchain-v4/activate
+          # Initialize dependencies.
+          ./init
 
-          # Run unit tests.
+          # Build release binaries
           cd build
-          ctest -R memgraph__unit --output-on-failure
+          cmake -DCMAKE_BUILD_TYPE=$BUILD_TYPE ..
+          make -j$THREADS
+
+      - name: Ensure Kafka and Pulsar are up
+        run: |
+          cd tests/e2e/streams/kafka
+          docker-compose up -d
+          cd ../pulsar
+          docker-compose up -d
 
       - name: Run e2e tests
         run: |
@@ -289,6 +357,40 @@ jobs:
           cd e2e
           ./run.sh
 
+      - name: Ensure Kafka and Pulsar are down
+        if: always()
+        run: |
+          cd tests/e2e/streams/kafka
+          docker-compose down
+          cd ../pulsar
+          docker-compose down
+
+  release_durability_stress_tests:
+    name: "Release durability and stress tests"
+    runs-on: [self-hosted, Linux, X64, Ubuntu20.04]
+    timeout-minutes: 60
+
+    steps:
+      - name: Set up repository
+        uses: actions/checkout@v4
+        with:
+          # Number of commits to fetch. `0` indicates all history for all
+          # branches and tags. (default: 1)
+          fetch-depth: 0
+
+      - name: Build release binaries
+        run: |
+          # Activate toolchain.
+          source /opt/toolchain-v4/activate
+
+          # Initialize dependencies.
+          ./init
+
+          # Build release binaries.
+          cd build
+          cmake -DCMAKE_BUILD_TYPE=$BUILD_TYPE ..
+          make -j$THREADS
+
       - name: Run stress test (plain)
         run: |
           cd tests/stress
@@ -299,11 +401,6 @@ jobs:
           cd tests/stress
           ./continuous_integration --use-ssl
 
-      - name: Run stress test (large)
-        run: |
-          cd tests/stress
-          ./continuous_integration --large-dataset
-
       - name: Run durability test (plain)
         run: |
           cd tests/stress

.github/workflows/stress_test_large.yaml

@@ -0,0 +1,62 @@
+name: Stress test large
+
+on:
+  workflow_dispatch:
+    inputs:
+      build_type:
+        type: choice
+        description: "Memgraph Build type. Default value is Release."
+        default: 'Release'
+        options:
+          - Release
+          - RelWithDebInfo
+
+  schedule:
+    - cron: "0 22 * * *"
+
+env:
+  THREADS: 24
+  MEMGRAPH_ENTERPRISE_LICENSE: ${{ secrets.MEMGRAPH_ENTERPRISE_LICENSE }}
+  MEMGRAPH_ORGANIZATION_NAME: ${{ secrets.MEMGRAPH_ORGANIZATION_NAME }}
+  BUILD_TYPE: ${{ github.event.inputs.build_type || 'Release' }}
+
+jobs:
+  stress_test_large:
+    name: "Stress test large"
+    timeout-minutes: 720
+    strategy:
+      matrix:
+        os: [Debian10, Ubuntu20.04]
+        extra: [BigMemory, Gen8]
+        exclude:
+          - os: Debian10
+            extra: Gen8
+          - os: Ubuntu20.04
+            extra: BigMemory
+    runs-on: [self-hosted, Linux, X64, "${{ matrix.os }}", "${{ matrix.extra }}"]
+
+    steps:
+      - name: Set up repository
+        uses: actions/checkout@v4
+        with:
+          # Number of commits to fetch. `0` indicates all history for all
+          # branches and tags. (default: 1)
+          fetch-depth: 0
+
+      - name: Build release binaries
+        run: |
+          # Activate toolchain.
+          source /opt/toolchain-v4/activate
+
+          # Initialize dependencies.
+          ./init
+
+          # Build release binaries.
+          cd build
+          cmake -DCMAKE_BUILD_TYPE=$BUILD_TYPE ..
+          make -j$THREADS
+
+      - name: Run stress test (large)
+        run: |
+          cd tests/stress
+          ./continuous_integration --large-dataset

.github/workflows/upload_to_s3.yaml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Download artifacts
-        uses: dawidd6/action-download-artifact@v2
+        uses: dawidd6/action-download-artifact@v4
         with:
           workflow: package_all.yaml
           workflow_conclusion: success

ADRs/002_nuraft.md

@@ -0,0 +1,34 @@
+# NuRaft ADR
+
+**Author**
+Marko Budiselic (github.com/gitbuda)
+
+**Status**
+PROPOSED
+
+**Date**
+January 10, 2024
+
+**Problem**
+
+In order to enhance Memgraph to have High Availability features as requested by
+customers, we want to have reliable coordinators backed by RAFT consensus algorithm. Implementing
+RAFT to be correct and performant is a very challenging task. Skillful Memgraph
+engineers already tried 3 times and failed to deliver in a reasonable timeframe
+all three times (approximately 4 person-weeks of engineering work each time).
+
+**Criteria**
+
+- easy integration with our C++ codebase
+- heavily tested in production environments
+- implementation of performance optimizations on top of the canonical Raft
+  implementation
+
+**Decision**
+
+There are a few, robust C++ implementations of Raft but as a part of other
+projects or bigger libraries. **We select
+[NuRaft](https://github.com/eBay/NuRaft)** because it focuses on delivering
+Raft without bloatware, and it's used by
+[Clickhouse](https://github.com/ClickHouse/ClickHouse) (an comparable peer to
+Memgraph, a very well-established product).

ADRs/003_rocksdb.md

@@ -0,0 +1,38 @@
+# RocksDB ADR
+
+**Author**
+Marko Budiselic (github.com/gitbuda)
+
+**Status**
+ACCEPTED
+
+**Date**
+January 23, 2024
+
+**Problem**
+
+Interacting with data (reads and writes) on disk in a concurrent, safe, and
+fast way is a challenging task. Implementing all low-level primitives to
+interact with various disk hardware efficiently consumes significant
+engineering people. Whenever Memgraph has to store data on disk (or any
+other colder than RAM storage system), the problem is how to do that in the
+least amount of development time while satisfying all functional requirements
+(often performance).
+
+**Criteria**
+
+- working efficiently in a highly concurrent environment
+- easy integration with Memgraph's C++ codebase
+- providing low-level key-value API
+- heavily tested in production environments
+- providing abstractions for the storage hardware (even for cloud-based
+  storages like S3)
+
+**Decision**
+
+There are a few robust key-value stores, but finding one that is
+production-ready and compatible with Memgraph's C++ codebase is challenging.
+**We select [RocksDB](https://github.com/facebook/rocksdb)** because it
+delivers robust API to manage data on disk; it's battle-tested in many
+production environments (many databases systems are embedding RocksDB), and
+it's the most compatible one.

CMakeLists.txt

@@ -271,6 +271,17 @@ endif()
 set(libs_dir ${CMAKE_SOURCE_DIR}/libs)
 add_subdirectory(libs EXCLUDE_FROM_ALL)
 
+option(MG_EXPERIMENTAL_HIGH_AVAILABILITY "Feature flag for experimental high availability" OFF)
+
+if (NOT MG_ENTERPRISE AND MG_EXPERIMENTAL_HIGH_AVAILABILITY)
+    set(MG_EXPERIMENTAL_HIGH_AVAILABILITY OFF)
+    message(FATAL_ERROR "MG_EXPERIMENTAL_HIGH_AVAILABILITY must be used with enterpise version of the code.")
+endif ()
+
+if (MG_EXPERIMENTAL_HIGH_AVAILABILITY)
+    add_compile_definitions(MG_EXPERIMENTAL_HIGH_AVAILABILITY)
+endif ()
+
 # Optional subproject configuration -------------------------------------------
 option(TEST_COVERAGE "Generate coverage reports from running memgraph" OFF)
 option(TOOLS "Build tools binaries" ON)

libs/CMakeLists.txt

@@ -294,3 +294,10 @@ set_path_external_library(jemalloc STATIC
   ${CMAKE_CURRENT_SOURCE_DIR}/jemalloc/include/)
 
 import_header_library(rangev3 ${CMAKE_CURRENT_SOURCE_DIR}/rangev3/include)
+
+# Setup NuRaft
+import_external_library(nuraft STATIC
+  ${CMAKE_CURRENT_SOURCE_DIR}/nuraft/lib/libnuraft.a
+  ${CMAKE_CURRENT_SOURCE_DIR}/nuraft/include/)
+find_package(OpenSSL REQUIRED)
+target_link_libraries(nuraft INTERFACE ${OPENSSL_LIBRARIES})

libs/setup.sh

@@ -126,6 +126,7 @@ declare -A primary_urls=(
   ["absl"]="https://$local_cache_host/git/abseil-cpp.git"
   ["jemalloc"]="https://$local_cache_host/git/jemalloc.git"
   ["range-v3"]="https://$local_cache_host/git/ericniebler/range-v3.git"
+  ["nuraft"]="https://$local_cache_host/git/eBay/NuRaft.git"
 )
 
 # The goal of secondary urls is to have links to the "source of truth" of
@@ -155,6 +156,7 @@ declare -A secondary_urls=(
   ["absl"]="https://github.com/abseil/abseil-cpp.git"
   ["jemalloc"]="https://github.com/jemalloc/jemalloc.git"
   ["range-v3"]="https://github.com/ericniebler/range-v3.git"
+  ["nuraft"]="https://github.com/eBay/NuRaft.git"
 )
 
 # antlr
@@ -277,3 +279,10 @@ popd
 #range-v3 release-0.12.0
 range_v3_ref="release-0.12.0"
 repo_clone_try_double "${primary_urls[range-v3]}" "${secondary_urls[range-v3]}" "rangev3" "$range_v3_ref"
+
+# NuRaft
+nuraft_tag="v2.1.0"
+repo_clone_try_double "${primary_urls[nuraft]}" "${secondary_urls[nuraft]}" "nuraft" "$nuraft_tag" true
+pushd nuraft
+./prepare.sh
+popd

licenses/BSL.txt

@@ -36,7 +36,7 @@ ADDITIONAL USE GRANT:   You may use the Licensed Work in accordance with the
                         3. using the Licensed Work to create a work or solution
                         which competes (or might reasonably be expected to
                         compete) with the Licensed Work.
-CHANGE DATE:            2027-08-12
+CHANGE DATE:            2028-21-01
 CHANGE LICENSE:         Apache License, Version 2.0
 
 For information about alternative licensing arrangements, please visit: https://memgraph.com/legal.

src/CMakeLists.txt

@@ -22,6 +22,10 @@ add_subdirectory(dbms)
 add_subdirectory(flags)
 add_subdirectory(distributed)
 add_subdirectory(replication)
+add_subdirectory(replication_handler)
+add_subdirectory(coordination)
+add_subdirectory(replication_coordination_glue)
+add_subdirectory(system)
 
 string(TOLOWER ${CMAKE_BUILD_TYPE} lower_build_type)
 
@@ -41,10 +45,10 @@ set(mg_single_node_v2_sources
 add_executable(memgraph ${mg_single_node_v2_sources})
 target_include_directories(memgraph PUBLIC ${CMAKE_SOURCE_DIR}/include)
 target_link_libraries(memgraph stdc++fs Threads::Threads
-        mg-telemetry mg-communication mg-communication-metrics mg-memory mg-utils mg-license mg-settings mg-glue mg-flags)
+        mg-telemetry mg-communication mg-communication-metrics mg-memory mg-utils mg-license mg-settings mg-glue mg-flags mg::system mg::replication_handler)
 
 # NOTE: `include/mg_procedure.syms` describes a pattern match for symbols which
-# should be dynamically exported, so that `dlopen` can correctly link the
+# should be dynamically exported, so that `dlopen` can correctly link th
 # symbols in custom procedure module libraries.
 target_link_libraries(memgraph "-Wl,--dynamic-list=${CMAKE_SOURCE_DIR}/include/mg_procedure.syms")
 set_target_properties(memgraph PROPERTIES

src/auth/CMakeLists.txt

@@ -2,7 +2,9 @@ set(auth_src_files
     auth.cpp
     crypto.cpp
     models.cpp
-    module.cpp)
+    module.cpp
+    rpc.cpp
+    replication_handlers.cpp)
 
 find_package(Seccomp REQUIRED)
 find_package(fmt REQUIRED)
@@ -11,7 +13,7 @@ find_package(gflags REQUIRED)
 
 add_library(mg-auth STATIC ${auth_src_files})
 target_link_libraries(mg-auth json libbcrypt gflags fmt::fmt)
-target_link_libraries(mg-auth mg-utils mg-kvstore mg-license )
+target_link_libraries(mg-auth mg-utils mg-kvstore mg-license mg::system mg-replication)
 
 target_link_libraries(mg-auth ${Seccomp_LIBRARIES})
 target_include_directories(mg-auth SYSTEM PRIVATE ${Seccomp_INCLUDE_DIRS})

src/auth/auth.cpp

@@ -8,17 +8,18 @@
 
 #include "auth/auth.hpp"
 
-#include <cstring>
 #include <iostream>
-#include <limits>
+#include <optional>
 #include <utility>
 
 #include <fmt/format.h>
 
+#include "auth/crypto.hpp"
 #include "auth/exceptions.hpp"
+#include "auth/rpc.hpp"
 #include "license/license.hpp"
+#include "system/transaction.hpp"
 #include "utils/flag_validation.hpp"
-#include "utils/logging.hpp"
 #include "utils/message.hpp"
 #include "utils/settings.hpp"
 #include "utils/string.hpp"
@@ -43,9 +44,84 @@ DEFINE_VALIDATED_int32(auth_module_timeout_ms, 10000,
                        FLAG_IN_RANGE(100, 1800000));
 
 namespace memgraph::auth {
+
+namespace {
+#ifdef MG_ENTERPRISE
+/**
+ * REPLICATION SYSTEM ACTION IMPLEMENTATIONS
+ */
+struct UpdateAuthData : memgraph::system::ISystemAction {
+  explicit UpdateAuthData(User user) : user_{std::move(user)}, role_{std::nullopt} {}
+  explicit UpdateAuthData(Role role) : user_{std::nullopt}, role_{std::move(role)} {}
+
+  void DoDurability() override { /* Done during Auth execution */
+  }
+
+  bool DoReplication(replication::ReplicationClient &client, replication::ReplicationEpoch const &epoch,
+                     memgraph::system::Transaction const &txn) const override {
+    auto check_response = [](const replication::UpdateAuthDataRes &response) { return response.success; };
+    if (user_) {
+      return client.SteamAndFinalizeDelta<replication::UpdateAuthDataRpc>(
+          check_response, std::string{epoch.id()}, txn.last_committed_system_timestamp(), txn.timestamp(), *user_);
+    }
+    if (role_) {
+      return client.SteamAndFinalizeDelta<replication::UpdateAuthDataRpc>(
+          check_response, std::string{epoch.id()}, txn.last_committed_system_timestamp(), txn.timestamp(), *role_);
+    }
+    // Should never get here
+    MG_ASSERT(false, "Trying to update auth data that is not a user nor a role");
+    return {};
+  }
+
+  void PostReplication(replication::RoleMainData &mainData) const override {}
+
+ private:
+  std::optional<User> user_;
+  std::optional<Role> role_;
+};
+
+struct DropAuthData : memgraph::system::ISystemAction {
+  enum class AuthDataType { USER, ROLE };
+
+  explicit DropAuthData(AuthDataType type, std::string_view name) : type_{type}, name_{name} {}
+
+  void DoDurability() override { /* Done during Auth execution */
+  }
+
+  bool DoReplication(replication::ReplicationClient &client, replication::ReplicationEpoch const &epoch,
+                     memgraph::system::Transaction const &txn) const override {
+    auto check_response = [](const replication::DropAuthDataRes &response) { return response.success; };
+
+    memgraph::replication::DropAuthDataReq::DataType type{};
+    switch (type_) {
+      case AuthDataType::USER:
+        type = memgraph::replication::DropAuthDataReq::DataType::USER;
+        break;
+      case AuthDataType::ROLE:
+        type = memgraph::replication::DropAuthDataReq::DataType::ROLE;
+        break;
+    }
+    return client.SteamAndFinalizeDelta<replication::DropAuthDataRpc>(
+        check_response, std::string{epoch.id()}, txn.last_committed_system_timestamp(), txn.timestamp(), type, name_);
+  }
+  void PostReplication(replication::RoleMainData &mainData) const override {}
+
+ private:
+  AuthDataType type_;
+  std::string name_;
+};
+#endif
+
+/**
+ * CONSTANTS
+ */
 const std::string kUserPrefix = "user:";
 const std::string kRolePrefix = "role:";
 const std::string kLinkPrefix = "link:";
+const std::string kVersion = "version";
+
+static constexpr auto kVersionV1 = "V1";
+}  // namespace
 
 /**
  * All data stored in the `Auth` storage is stored in an underlying
@@ -64,7 +140,59 @@ const std::string kLinkPrefix = "link:";
  * key="link:<username>", value="<rolename>"
  */
 
-Auth::Auth(const std::string &storage_directory) : storage_(storage_directory), module_(FLAGS_auth_module_executable) {}
+namespace {
+void MigrateVersions(kvstore::KVStore &store) {
+  static constexpr auto kPasswordHashV0V1 = "password_hash";
+  auto version_str = store.Get(kVersion);
+
+  if (!version_str) {
+    using namespace std::string_literals;
+
+    // pre versioning, add version to the store
+    auto puts = std::map<std::string, std::string>{{kVersion, kVersionV1}};
+
+    // also add hash kind into durability
+
+    auto it = store.begin(kUserPrefix);
+    auto const e = store.end(kUserPrefix);
+
+    if (it != e) {
+      const auto hash_algo = CurrentHashAlgorithm();
+      spdlog::info("Updating auth durability, assuming previously stored as {}", AsString(hash_algo));
+
+      for (; it != e; ++it) {
+        auto const &[key, value] = *it;
+        try {
+          auto user_data = nlohmann::json::parse(value);
+
+          auto password_hash = user_data[kPasswordHashV0V1];
+          if (!password_hash.is_string()) {
+            throw AuthException("Couldn't load user data!");
+          }
+          // upgrade the password_hash to include the hash algortihm
+          if (password_hash.empty()) {
+            user_data[kPasswordHashV0V1] = nullptr;
+          } else {
+            user_data[kPasswordHashV0V1] = HashedPassword{hash_algo, password_hash};
+          }
+          puts.emplace(key, user_data.dump());
+        } catch (const nlohmann::json::parse_error &e) {
+          throw AuthException("Couldn't load user data!");
+        }
+      }
+    }
+
+    // Perform migration to V1
+    store.PutMultiple(puts);
+    version_str = kVersionV1;
+  }
+}
+};  // namespace
+
+Auth::Auth(std::string storage_directory, Config config)
+    : storage_(std::move(storage_directory)), module_(FLAGS_auth_module_executable), config_{std::move(config)} {
+  MigrateVersions(storage_);
+}
 
 std::optional<User> Auth::Authenticate(const std::string &username, const std::string &password) {
   if (module_.IsUsed()) {
@@ -95,6 +223,12 @@ std::optional<User> Auth::Authenticate(const std::string &username, const std::s
     // Authenticate the user.
     if (!is_authenticated) return std::nullopt;
 
+    /**
+     * TODO
+     * The auth module should not update auth data.
+     * There is now way to replicate it and we should not be storing sensitive data if we don't have to.
+     */
+
     // Find or create the user and return it.
     auto user = GetUser(username);
     if (!user) {
@@ -113,7 +247,7 @@ std::optional<User> Auth::Authenticate(const std::string &username, const std::s
         return std::nullopt;
       }
     } else {
-      user->UpdatePassword(password);
+      UpdatePassword(*user, password);
     }
     if (FLAGS_auth_module_manage_roles) {
       if (!rolename.empty()) {
@@ -155,6 +289,10 @@ std::optional<User> Auth::Authenticate(const std::string &username, const std::s
                                           username, "https://memgr.ph/auth"));
       return std::nullopt;
     }
+    if (user->UpgradeHash(password)) {
+      SaveUser(*user);
+    }
+
     return user;
   }
 }
@@ -183,7 +321,7 @@ std::optional<User> Auth::GetUser(const std::string &username_orig) const {
   return user;
 }
 
-void Auth::SaveUser(const User &user) {
+void Auth::SaveUser(const User &user, system::Transaction *system_tx) {
   bool success = false;
   if (const auto *role = user.role(); role != nullptr) {
     success = storage_.PutMultiple(
@@ -195,28 +333,72 @@ void Auth::SaveUser(const User &user) {
   if (!success) {
     throw AuthException("Couldn't save user '{}'!", user.username());
   }
-  // TODO system delta
+  // All changes to the user end up calling this function, so no need to add a delta anywhere else
+  if (system_tx) {
+#ifdef MG_ENTERPRISE
+    system_tx->AddAction<UpdateAuthData>(user);
+#endif
+  }
 }
 
-std::optional<User> Auth::AddUser(const std::string &username, const std::optional<std::string> &password) {
+void Auth::UpdatePassword(auth::User &user, const std::optional<std::string> &password) {
+  // Check if null
+  if (!password) {
+    if (!config_.password_permit_null) {
+      throw AuthException("Null passwords aren't permitted!");
+    }
+  } else {
+    // Check if compliant with our filter
+    if (config_.custom_password_regex) {
+      if (const auto license_check_result = license::global_license_checker.IsEnterpriseValid(utils::global_settings);
+          license_check_result.HasError()) {
+        throw AuthException(
+            "Custom password regex is a Memgraph Enterprise feature. Please set the config "
+            "(\"--auth-password-strength-regex\") to its default value (\"{}\") or remove the flag.\n{}",
+            glue::kDefaultPasswordRegex,
+            license::LicenseCheckErrorToString(license_check_result.GetError(), "password regex"));
+      }
+    }
+    if (!std::regex_match(*password, config_.password_regex)) {
+      throw AuthException(
+          "The user password doesn't conform to the required strength! Regex: "
+          "\"{}\"",
+          config_.password_regex_str);
+    }
+  }
+
+  // All checks passed; update
+  user.UpdatePassword(password);
+}
+
+std::optional<User> Auth::AddUser(const std::string &username, const std::optional<std::string> &password,
+                                  system::Transaction *system_tx) {
+  if (!NameRegexMatch(username)) {
+    throw AuthException("Invalid user name.");
+  }
   auto existing_user = GetUser(username);
   if (existing_user) return std::nullopt;
   auto existing_role = GetRole(username);
   if (existing_role) return std::nullopt;
   auto new_user = User(username);
-  new_user.UpdatePassword(password);
-  SaveUser(new_user);
+  UpdatePassword(new_user, password);
+  SaveUser(new_user, system_tx);
   return new_user;
 }
 
-bool Auth::RemoveUser(const std::string &username_orig) {
+bool Auth::RemoveUser(const std::string &username_orig, system::Transaction *system_tx) {
   auto username = utils::ToLowerCase(username_orig);
   if (!storage_.Get(kUserPrefix + username)) return false;
   std::vector<std::string> keys({kLinkPrefix + username, kUserPrefix + username});
   if (!storage_.DeleteMultiple(keys)) {
     throw AuthException("Couldn't remove user '{}'!", username);
   }
-  // TODO system delta
+  // Handling drop user delta
+  if (system_tx) {
+#ifdef MG_ENTERPRISE
+    system_tx->AddAction<DropAuthData>(DropAuthData::AuthDataType::USER, username);
+#endif
+  }
   return true;
 }
 
@@ -233,6 +415,19 @@ std::vector<auth::User> Auth::AllUsers() const {
   return ret;
 }
 
+std::vector<std::string> Auth::AllUsernames() const {
+  std::vector<std::string> ret;
+  for (auto it = storage_.begin(kUserPrefix); it != storage_.end(kUserPrefix); ++it) {
+    auto username = it->first.substr(kUserPrefix.size());
+    if (username != utils::ToLowerCase(username)) continue;
+    auto user = GetUser(username);
+    if (user) {
+      ret.push_back(username);
+    }
+  }
+  return ret;
+}
+
 bool Auth::HasUsers() const { return storage_.begin(kUserPrefix) != storage_.end(kUserPrefix); }
 
 std::optional<Role> Auth::GetRole(const std::string &rolename_orig) const {
@@ -250,22 +445,30 @@ std::optional<Role> Auth::GetRole(const std::string &rolename_orig) const {
   return Role::Deserialize(data);
 }
 
-void Auth::SaveRole(const Role &role) {
+void Auth::SaveRole(const Role &role, system::Transaction *system_tx) {
   if (!storage_.Put(kRolePrefix + role.rolename(), role.Serialize().dump())) {
     throw AuthException("Couldn't save role '{}'!", role.rolename());
   }
-  // TODO system delta
+  // All changes to the role end up calling this function, so no need to add a delta anywhere else
+  if (system_tx) {
+#ifdef MG_ENTERPRISE
+    system_tx->AddAction<UpdateAuthData>(role);
+#endif
+  }
 }
 
-std::optional<Role> Auth::AddRole(const std::string &rolename) {
+std::optional<Role> Auth::AddRole(const std::string &rolename, system::Transaction *system_tx) {
+  if (!NameRegexMatch(rolename)) {
+    throw AuthException("Invalid role name.");
+  }
   if (auto existing_role = GetRole(rolename)) return std::nullopt;
   if (auto existing_user = GetUser(rolename)) return std::nullopt;
   auto new_role = Role(rolename);
-  SaveRole(new_role);
+  SaveRole(new_role, system_tx);
   return new_role;
 }
 
-bool Auth::RemoveRole(const std::string &rolename_orig) {
+bool Auth::RemoveRole(const std::string &rolename_orig, system::Transaction *system_tx) {
   auto rolename = utils::ToLowerCase(rolename_orig);
   if (!storage_.Get(kRolePrefix + rolename)) return false;
   std::vector<std::string> keys;
@@ -278,7 +481,12 @@ bool Auth::RemoveRole(const std::string &rolename_orig) {
   if (!storage_.DeleteMultiple(keys)) {
     throw AuthException("Couldn't remove role '{}'!", rolename);
   }
-  // TODO system delta
+  // Handling drop role delta
+  if (system_tx) {
+#ifdef MG_ENTERPRISE
+    system_tx->AddAction<DropAuthData>(DropAuthData::AuthDataType::ROLE, rolename);
+#endif
+  }
   return true;
 }
 
@@ -296,6 +504,18 @@ std::vector<auth::Role> Auth::AllRoles() const {
   return ret;
 }
 
+std::vector<std::string> Auth::AllRolenames() const {
+  std::vector<std::string> ret;
+  for (auto it = storage_.begin(kRolePrefix); it != storage_.end(kRolePrefix); ++it) {
+    auto rolename = it->first.substr(kRolePrefix.size());
+    if (rolename != utils::ToLowerCase(rolename)) continue;
+    if (auto role = GetRole(rolename)) {
+      ret.push_back(rolename);
+    }
+  }
+  return ret;
+}
+
 std::vector<auth::User> Auth::AllUsersForRole(const std::string &rolename_orig) const {
   const auto rolename = utils::ToLowerCase(rolename_orig);
   std::vector<auth::User> ret;
@@ -315,52 +535,67 @@ std::vector<auth::User> Auth::AllUsersForRole(const std::string &rolename_orig)
 }
 
 #ifdef MG_ENTERPRISE
-bool Auth::GrantDatabaseToUser(const std::string &db, const std::string &name) {
+bool Auth::GrantDatabaseToUser(const std::string &db, const std::string &name, system::Transaction *system_tx) {
   if (auto user = GetUser(name)) {
     if (db == kAllDatabases) {
       user->db_access().GrantAll();
     } else {
       user->db_access().Add(db);
     }
-    SaveUser(*user);
+    SaveUser(*user, system_tx);
     return true;
   }
   return false;
 }
 
-bool Auth::RevokeDatabaseFromUser(const std::string &db, const std::string &name) {
+bool Auth::RevokeDatabaseFromUser(const std::string &db, const std::string &name, system::Transaction *system_tx) {
   if (auto user = GetUser(name)) {
     if (db == kAllDatabases) {
       user->db_access().DenyAll();
     } else {
       user->db_access().Remove(db);
     }
-    SaveUser(*user);
+    SaveUser(*user, system_tx);
     return true;
   }
   return false;
 }
 
-void Auth::DeleteDatabase(const std::string &db) {
+void Auth::DeleteDatabase(const std::string &db, system::Transaction *system_tx) {
   for (auto it = storage_.begin(kUserPrefix); it != storage_.end(kUserPrefix); ++it) {
     auto username = it->first.substr(kUserPrefix.size());
     if (auto user = GetUser(username)) {
       user->db_access().Delete(db);
-      SaveUser(*user);
+      SaveUser(*user, system_tx);
     }
   }
 }
 
-bool Auth::SetMainDatabase(std::string_view db, const std::string &name) {
+bool Auth::SetMainDatabase(std::string_view db, const std::string &name, system::Transaction *system_tx) {
   if (auto user = GetUser(name)) {
     if (!user->db_access().SetDefault(db)) {
       throw AuthException("Couldn't set default database '{}' for user '{}'!", db, name);
     }
-    SaveUser(*user);
+    SaveUser(*user, system_tx);
     return true;
   }
   return false;
 }
 #endif
 
+bool Auth::NameRegexMatch(const std::string &user_or_role) const {
+  if (config_.custom_name_regex) {
+    if (const auto license_check_result =
+            memgraph::license::global_license_checker.IsEnterpriseValid(memgraph::utils::global_settings);
+        license_check_result.HasError()) {
+      throw memgraph::auth::AuthException(
+          "Custom user/role regex is a Memgraph Enterprise feature. Please set the config "
+          "(\"--auth-user-or-role-name-regex\") to its default value (\"{}\") or remove the flag.\n{}",
+          glue::kDefaultUserRoleRegex,
+          memgraph::license::LicenseCheckErrorToString(license_check_result.GetError(), "user/role regex"));
+    }
+  }
+  return std::regex_match(user_or_role, config_.name_regex);
+}
+
 }  // namespace memgraph::auth

src/auth/auth.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Licensed as a Memgraph Enterprise file under the Memgraph Enterprise
 // License (the "License"); by using this file, you agree to be bound by the terms of the License, and you may not use
@@ -10,16 +10,23 @@
 
 #include <mutex>
 #include <optional>
+#include <regex>
 #include <vector>
 
 #include "auth/exceptions.hpp"
 #include "auth/models.hpp"
 #include "auth/module.hpp"
+#include "glue/auth_global.hpp"
 #include "kvstore/kvstore.hpp"
+#include "system/action.hpp"
 #include "utils/settings.hpp"
+#include "utils/synchronized.hpp"
 
 namespace memgraph::auth {
 
+class Auth;
+using SynchedAuth = memgraph::utils::Synchronized<memgraph::auth::Auth, memgraph::utils::WritePrioritizedRWLock>;
+
 static const constexpr char *const kAllDatabases = "*";
 
 /**
@@ -31,7 +38,47 @@ static const constexpr char *const kAllDatabases = "*";
  */
 class Auth final {
  public:
-  explicit Auth(const std::string &storage_directory);
+  struct Config {
+    Config() {}
+    Config(std::string name_regex, std::string password_regex, bool password_permit_null)
+        : name_regex_str{std::move(name_regex)},
+          password_regex_str{std::move(password_regex)},
+          password_permit_null{password_permit_null},
+          custom_name_regex{name_regex_str != glue::kDefaultUserRoleRegex},
+          name_regex{name_regex_str},
+          custom_password_regex{password_regex_str != glue::kDefaultPasswordRegex},
+          password_regex{password_regex_str} {}
+
+    std::string name_regex_str{glue::kDefaultUserRoleRegex};
+    std::string password_regex_str{glue::kDefaultPasswordRegex};
+    bool password_permit_null{true};
+
+   private:
+    friend class Auth;
+    bool custom_name_regex{false};
+    std::regex name_regex{name_regex_str};
+    bool custom_password_regex{false};
+    std::regex password_regex{password_regex_str};
+  };
+
+  explicit Auth(std::string storage_directory, Config config);
+
+  /**
+   * @brief Set the Config object
+   *
+   * @param config
+   */
+  void SetConfig(Config config) {
+    // NOTE: The Auth class itself is not thread-safe, higher-level code needs to synchronize it when using it.
+    config_ = std::move(config);
+  }
+
+  /**
+   * @brief
+   *
+   * @return Config
+   */
+  Config GetConfig() const { return config_; }
 
   /**
    * Authenticates a user using his username and password.
@@ -61,7 +108,7 @@ class Auth final {
    *
    * @throw AuthException if unable to save the user.
    */
-  void SaveUser(const User &user);
+  void SaveUser(const User &user, system::Transaction *system_tx = nullptr);
 
   /**
    * Creates a user if the user doesn't exist.
@@ -72,7 +119,8 @@ class Auth final {
    * @return a user when the user is created, nullopt if the user exists
    * @throw AuthException if unable to save the user.
    */
-  std::optional<User> AddUser(const std::string &username, const std::optional<std::string> &password = std::nullopt);
+  std::optional<User> AddUser(const std::string &username, const std::optional<std::string> &password = std::nullopt,
+                              system::Transaction *system_tx = nullptr);
 
   /**
    * Removes a user from the storage.
@@ -83,7 +131,15 @@ class Auth final {
    *         doesn't exist
    * @throw AuthException if unable to remove the user.
    */
-  bool RemoveUser(const std::string &username);
+  bool RemoveUser(const std::string &username, system::Transaction *system_tx = nullptr);
+
+  /**
+   * @brief
+   *
+   * @param user
+   * @param password
+   */
+  void UpdatePassword(auth::User &user, const std::optional<std::string> &password);
 
   /**
    * Gets all users from the storage.
@@ -93,6 +149,13 @@ class Auth final {
    */
   std::vector<User> AllUsers() const;
 
+  /**
+   * @brief
+   *
+   * @return std::vector<std::string>
+   */
+  std::vector<std::string> AllUsernames() const;
+
   /**
    * Returns whether there are users in the storage.
    *
@@ -117,7 +180,7 @@ class Auth final {
    *
    * @throw AuthException if unable to save the role.
    */
-  void SaveRole(const Role &role);
+  void SaveRole(const Role &role, system::Transaction *system_tx = nullptr);
 
   /**
    * Creates a role if the role doesn't exist.
@@ -127,7 +190,7 @@ class Auth final {
    * @return a role when the role is created, nullopt if the role exists
    * @throw AuthException if unable to save the role.
    */
-  std::optional<Role> AddRole(const std::string &rolename);
+  std::optional<Role> AddRole(const std::string &rolename, system::Transaction *system_tx = nullptr);
 
   /**
    * Removes a role from the storage.
@@ -138,7 +201,7 @@ class Auth final {
    *         doesn't exist
    * @throw AuthException if unable to remove the role.
    */
-  bool RemoveRole(const std::string &rolename);
+  bool RemoveRole(const std::string &rolename, system::Transaction *system_tx = nullptr);
 
   /**
    * Gets all roles from the storage.
@@ -148,6 +211,13 @@ class Auth final {
    */
   std::vector<Role> AllRoles() const;
 
+  /**
+   * @brief
+   *
+   * @return std::vector<std::string>
+   */
+  std::vector<std::string> AllRolenames() const;
+
   /**
    * Gets all users for a role from the storage.
    *
@@ -167,7 +237,7 @@ class Auth final {
    * @return true on success
    * @throw AuthException if unable to find or update the user
    */
-  bool RevokeDatabaseFromUser(const std::string &db, const std::string &name);
+  bool RevokeDatabaseFromUser(const std::string &db, const std::string &name, system::Transaction *system_tx = nullptr);
 
   /**
    * @brief Grant access to individual database for a user.
@@ -177,7 +247,7 @@ class Auth final {
    * @return true on success
    * @throw AuthException if unable to find or update the user
    */
-  bool GrantDatabaseToUser(const std::string &db, const std::string &name);
+  bool GrantDatabaseToUser(const std::string &db, const std::string &name, system::Transaction *system_tx = nullptr);
 
   /**
    * @brief Delete a database from all users.
@@ -185,7 +255,7 @@ class Auth final {
    * @param db name of the database to delete
    * @throw AuthException if unable to read data
    */
-  void DeleteDatabase(const std::string &db);
+  void DeleteDatabase(const std::string &db, system::Transaction *system_tx = nullptr);
 
   /**
    * @brief Set main database for an individual user.
@@ -195,14 +265,24 @@ class Auth final {
    * @return true on success
    * @throw AuthException if unable to find or update the user
    */
-  bool SetMainDatabase(std::string_view db, const std::string &name);
+  bool SetMainDatabase(std::string_view db, const std::string &name, system::Transaction *system_tx = nullptr);
 #endif
 
  private:
+  /**
+   * @brief
+   *
+   * @param user_or_role
+   * @return true
+   * @return false
+   */
+  bool NameRegexMatch(const std::string &user_or_role) const;
+
   // Even though the `kvstore::KVStore` class is guaranteed to be thread-safe,
   // Auth is not thread-safe because modifying users and roles might require
   // more than one operation on the storage.
   kvstore::KVStore storage_;
   auth::Module module_;
+  Config config_;
 };
 }  // namespace memgraph::auth

src/auth/crypto.cpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Licensed as a Memgraph Enterprise file under the Memgraph Enterprise
 // License (the "License"); by using this file, you agree to be bound by the terms of the License, and you may not use
@@ -22,10 +22,14 @@
 
 namespace {
 using namespace std::literals;
-inline constexpr std::array password_encryption_mappings{
-    std::pair{"bcrypt"sv, memgraph::auth::PasswordEncryptionAlgorithm::BCRYPT},
-    std::pair{"sha256"sv, memgraph::auth::PasswordEncryptionAlgorithm::SHA256},
-    std::pair{"sha256-multiple"sv, memgraph::auth::PasswordEncryptionAlgorithm::SHA256_MULTIPLE}};
+
+constexpr auto kHashAlgo = "hash_algo";
+constexpr auto kPasswordHash = "password_hash";
+
+inline constexpr std::array password_hash_mappings{
+    std::pair{"bcrypt"sv, memgraph::auth::PasswordHashAlgorithm::BCRYPT},
+    std::pair{"sha256"sv, memgraph::auth::PasswordHashAlgorithm::SHA256},
+    std::pair{"sha256-multiple"sv, memgraph::auth::PasswordHashAlgorithm::SHA256_MULTIPLE}};
 
 inline constexpr uint64_t ONE_SHA_ITERATION = 1;
 inline constexpr uint64_t MULTIPLE_SHA_ITERATIONS = 1024;
@@ -35,7 +39,7 @@ inline constexpr uint64_t MULTIPLE_SHA_ITERATIONS = 1024;
 DEFINE_VALIDATED_string(password_encryption_algorithm, "bcrypt",
                         "The password encryption algorithm used for authentication.", {
                           if (const auto result =
-                                  memgraph::utils::IsValidEnumValueString(value, password_encryption_mappings);
+                                  memgraph::utils::IsValidEnumValueString(value, password_hash_mappings);
                               result.HasError()) {
                             const auto error = result.GetError();
                             switch (error) {
@@ -45,7 +49,7 @@ DEFINE_VALIDATED_string(password_encryption_algorithm, "bcrypt",
                               }
                               case memgraph::utils::ValidationError::InvalidValue: {
                                 std::cout << "Invalid value for password encryption algorithm. Allowed values: "
-                                          << memgraph::utils::GetAllowedEnumValuesString(password_encryption_mappings)
+                                          << memgraph::utils::GetAllowedEnumValuesString(password_hash_mappings)
                                           << std::endl;
                                 break;
                               }
@@ -58,7 +62,7 @@ DEFINE_VALIDATED_string(password_encryption_algorithm, "bcrypt",
 
 namespace memgraph::auth {
 namespace BCrypt {
-std::string EncryptPassword(const std::string &password) {
+std::string HashPassword(const std::string &password) {
   char salt[BCRYPT_HASHSIZE];
   char hash[BCRYPT_HASHSIZE];
 
@@ -86,16 +90,30 @@ bool VerifyPassword(const std::string &password, const std::string &hash) {
 }  // namespace BCrypt
 
 namespace SHA {
+
+namespace {
+
+constexpr auto SHA_LENGTH = 64U;
+constexpr auto SALT_SIZE = 16U;
+constexpr auto SALT_SIZE_DURABLE = SALT_SIZE * 2;
+
 #if OPENSSL_VERSION_MAJOR >= 3
-std::string EncryptPasswordOpenSSL3(const std::string &password, const uint64_t number_of_iterations) {
+std::string HashPasswordOpenSSL3(std::string_view password, const uint64_t number_of_iterations,
+                                 std::string_view salt) {
   unsigned char hash[SHA256_DIGEST_LENGTH];
 
   EVP_MD_CTX *ctx = EVP_MD_CTX_new();
   EVP_MD *md = EVP_MD_fetch(nullptr, "SHA2-256", nullptr);
 
   EVP_DigestInit_ex(ctx, md, nullptr);
+
+  if (!salt.empty()) {
+    DMG_ASSERT(salt.size() == SALT_SIZE);
+    EVP_DigestUpdate(ctx, salt.data(), salt.size());
+  }
+
   for (auto i = 0; i < number_of_iterations; i++) {
-    EVP_DigestUpdate(ctx, password.c_str(), password.size());
+    EVP_DigestUpdate(ctx, password.data(), password.size());
   }
   EVP_DigestFinal_ex(ctx, hash, nullptr);
 
@@ -103,6 +121,11 @@ std::string EncryptPasswordOpenSSL3(const std::string &password, const uint64_t
   EVP_MD_CTX_free(ctx);
 
   std::stringstream result_stream;
+
+  for (unsigned char salt_char : salt) {
+    result_stream << std::hex << std::setw(2) << std::setfill('0') << (((unsigned int)salt_char) & 0xFFU);
+  }
+
   for (auto hash_char : hash) {
     result_stream << std::hex << std::setw(2) << std::setfill('0') << (int)hash_char;
   }
@@ -110,17 +133,27 @@ std::string EncryptPasswordOpenSSL3(const std::string &password, const uint64_t
   return result_stream.str();
 }
 #else
-std::string EncryptPasswordOpenSSL1_1(const std::string &password, const uint64_t number_of_iterations) {
+std::string HashPasswordOpenSSL1_1(std::string_view password, const uint64_t number_of_iterations,
+                                   std::string_view salt) {
   unsigned char hash[SHA256_DIGEST_LENGTH];
 
   SHA256_CTX sha256;
   SHA256_Init(&sha256);
+
+  if (!salt.empty()) {
+    DMG_ASSERT(salt.size() == SALT_SIZE);
+    SHA256_Update(&sha256, salt.data(), salt.size());
+  }
+
   for (auto i = 0; i < number_of_iterations; i++) {
-    SHA256_Update(&sha256, password.c_str(), password.size());
+    SHA256_Update(&sha256, password.data(), password.size());
   }
   SHA256_Final(hash, &sha256);
 
   std::stringstream ss;
+  for (unsigned char salt_char : salt) {
+    ss << std::hex << std::setw(2) << std::setfill('0') << (((unsigned int)salt_char) & 0xFFU);
+  }
   for (auto hash_char : hash) {
     ss << std::hex << std::setw(2) << std::setfill('0') << (int)hash_char;
   }
@@ -129,55 +162,144 @@ std::string EncryptPasswordOpenSSL1_1(const std::string &password, const uint64_
 }
 #endif
 
-std::string EncryptPassword(const std::string &password, const uint64_t number_of_iterations) {
+std::string HashPassword(std::string_view password, const uint64_t number_of_iterations, std::string_view salt) {
 #if OPENSSL_VERSION_MAJOR >= 3
-  return EncryptPasswordOpenSSL3(password, number_of_iterations);
+  return HashPasswordOpenSSL3(password, number_of_iterations, salt);
 #else
-  return EncryptPasswordOpenSSL1_1(password, number_of_iterations);
+  return HashPasswordOpenSSL1_1(password, number_of_iterations, salt);
 #endif
 }
 
-bool VerifyPassword(const std::string &password, const std::string &hash, const uint64_t number_of_iterations) {
-  auto password_hash = EncryptPassword(password, number_of_iterations);
+auto ExtractSalt(std::string_view salt_durable) -> std::array<char, SALT_SIZE> {
+  static_assert(SALT_SIZE_DURABLE % 2 == 0);
+  static_assert(SALT_SIZE_DURABLE / 2 == SALT_SIZE);
+
+  MG_ASSERT(salt_durable.size() == SALT_SIZE_DURABLE);
+  auto const *b = salt_durable.cbegin();
+  auto const *const e = salt_durable.cend();
+
+  auto salt = std::array<char, SALT_SIZE>{};
+  auto *inserter = salt.begin();
+
+  auto const toval = [](char a) -> uint8_t {
+    if ('0' <= a && a <= '9') {
+      return a - '0';
+    }
+    if ('a' <= a && a <= 'f') {
+      return 10 + (a - 'a');
+    }
+    MG_ASSERT(false, "Currupt hash, can't extract salt");
+    __builtin_unreachable();
+  };
+
+  for (; b != e; b += 2, ++inserter) {
+    *inserter = static_cast<char>(static_cast<uint8_t>(toval(b[0]) << 4U) | toval(b[1]));
+  }
+  return salt;
+}
+
+bool IsSalted(std::string_view hash) { return hash.size() == SHA_LENGTH + SALT_SIZE_DURABLE; }
+
+bool VerifyPassword(std::string_view password, std::string_view hash, const uint64_t number_of_iterations) {
+  auto password_hash = std::invoke([&] {
+    if (hash.size() == SHA_LENGTH) [[unlikely]] {
+      // Just SHA256
+      return HashPassword(password, number_of_iterations, {});
+    } else {
+      // SHA256 + SALT
+      MG_ASSERT(IsSalted(hash));
+      auto const salt_durable = std::string_view{hash.data(), SALT_SIZE_DURABLE};
+      std::array<char, SALT_SIZE> salt = ExtractSalt(salt_durable);
+      return HashPassword(password, number_of_iterations, {salt.data(), salt.size()});
+    }
+  });
   return password_hash == hash;
 }
+
+}  // namespace
+
 }  // namespace SHA
 
-bool VerifyPassword(const std::string &password, const std::string &hash) {
-  const auto password_encryption_algorithm = utils::StringToEnum<PasswordEncryptionAlgorithm>(
-      FLAGS_password_encryption_algorithm, password_encryption_mappings);
+HashedPassword HashPassword(const std::string &password, std::optional<PasswordHashAlgorithm> override_algo) {
+  auto const hash_algo = override_algo.value_or(CurrentHashAlgorithm());
+  auto password_hash = std::invoke([&] {
+    switch (hash_algo) {
+      case PasswordHashAlgorithm::BCRYPT: {
+        return BCrypt::HashPassword(password);
+      }
+      case PasswordHashAlgorithm::SHA256:
+      case PasswordHashAlgorithm::SHA256_MULTIPLE: {
+        auto gen = std::mt19937(std::random_device{}());
+        auto salt = std::array<char, SHA::SALT_SIZE>{};
+        auto dis = std::uniform_int_distribution<unsigned char>(0, 255);
+        std::generate(salt.begin(), salt.end(), [&]() { return dis(gen); });
+        auto iterations = (hash_algo == PasswordHashAlgorithm::SHA256) ? ONE_SHA_ITERATION : MULTIPLE_SHA_ITERATIONS;
+        return SHA::HashPassword(password, iterations, {salt.data(), salt.size()});
+      }
+    }
+  });
+  return HashedPassword{hash_algo, std::move(password_hash)};
+};
 
-  if (!password_encryption_algorithm.has_value()) {
-    throw AuthException("Invalid password encryption flag '{}'!", FLAGS_password_encryption_algorithm);
+namespace {
+
+auto InternalParseHashAlgorithm(std::string_view algo) -> PasswordHashAlgorithm {
+  auto maybe_parsed = utils::StringToEnum<PasswordHashAlgorithm>(algo, password_hash_mappings);
+  if (!maybe_parsed) {
+    throw AuthException("Invalid password encryption '{}'!", algo);
   }
-
-  switch (password_encryption_algorithm.value()) {
-    case PasswordEncryptionAlgorithm::BCRYPT:
-      return BCrypt::VerifyPassword(password, hash);
-    case PasswordEncryptionAlgorithm::SHA256:
-      return SHA::VerifyPassword(password, hash, ONE_SHA_ITERATION);
-    case PasswordEncryptionAlgorithm::SHA256_MULTIPLE:
-      return SHA::VerifyPassword(password, hash, MULTIPLE_SHA_ITERATIONS);
-  }
-
-  throw AuthException("Invalid password encryption flag '{}'!", FLAGS_password_encryption_algorithm);
+  return *maybe_parsed;
 }
 
-std::string EncryptPassword(const std::string &password) {
-  const auto password_encryption_algorithm = utils::StringToEnum<PasswordEncryptionAlgorithm>(
-      FLAGS_password_encryption_algorithm, password_encryption_mappings);
+PasswordHashAlgorithm &InternalCurrentHashAlgorithm() {
+  static auto current = PasswordHashAlgorithm::BCRYPT;
+  static std::once_flag flag;
+  std::call_once(flag, [] { current = InternalParseHashAlgorithm(FLAGS_password_encryption_algorithm); });
+  return current;
+}
+}  // namespace
 
-  if (!password_encryption_algorithm.has_value()) {
-    throw AuthException("Invalid password encryption flag '{}'!", FLAGS_password_encryption_algorithm);
+auto CurrentHashAlgorithm() -> PasswordHashAlgorithm { return InternalCurrentHashAlgorithm(); }
+
+void SetHashAlgorithm(std::string_view algo) {
+  auto &current = InternalCurrentHashAlgorithm();
+  current = InternalParseHashAlgorithm(algo);
+}
+
+auto AsString(PasswordHashAlgorithm hash_algo) -> std::string_view {
+  return *utils::EnumToString<PasswordHashAlgorithm>(hash_algo, password_hash_mappings);
+}
+
+bool HashedPassword::VerifyPassword(const std::string &password) {
+  switch (hash_algo) {
+    case PasswordHashAlgorithm::BCRYPT:
+      return BCrypt::VerifyPassword(password, password_hash);
+    case PasswordHashAlgorithm::SHA256:
+      return SHA::VerifyPassword(password, password_hash, ONE_SHA_ITERATION);
+    case PasswordHashAlgorithm::SHA256_MULTIPLE:
+      return SHA::VerifyPassword(password, password_hash, MULTIPLE_SHA_ITERATIONS);
   }
+}
 
-  switch (password_encryption_algorithm.value()) {
-    case PasswordEncryptionAlgorithm::BCRYPT:
-      return BCrypt::EncryptPassword(password);
-    case PasswordEncryptionAlgorithm::SHA256:
-      return SHA::EncryptPassword(password, ONE_SHA_ITERATION);
-    case PasswordEncryptionAlgorithm::SHA256_MULTIPLE:
-      return SHA::EncryptPassword(password, MULTIPLE_SHA_ITERATIONS);
+void to_json(nlohmann::json &j, const HashedPassword &p) {
+  j = nlohmann::json{{kHashAlgo, p.hash_algo}, {kPasswordHash, p.password_hash}};
+}
+
+void from_json(const nlohmann::json &j, HashedPassword &p) {
+  // NOLINTNEXTLINE(cppcoreguidelines-init-variables)
+  PasswordHashAlgorithm hash_algo;
+  j.at(kHashAlgo).get_to(hash_algo);
+  auto password_hash = j.value(kPasswordHash, std::string());
+  p = HashedPassword{hash_algo, std::move(password_hash)};
+}
+
+bool HashedPassword::IsSalted() const {
+  switch (hash_algo) {
+    case PasswordHashAlgorithm::BCRYPT:
+      return true;
+    case PasswordHashAlgorithm::SHA256:
+    case PasswordHashAlgorithm::SHA256_MULTIPLE:
+      return SHA::IsSalted(password_hash);
   }
 }
 

src/auth/crypto.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Licensed as a Memgraph Enterprise file under the Memgraph Enterprise
 // License (the "License"); by using this file, you agree to be bound by the terms of the License, and you may not use
@@ -8,14 +8,45 @@
 
 #pragma once
 
+#include <json/json.hpp>
+#include <optional>
 #include <string>
 
 namespace memgraph::auth {
-enum class PasswordEncryptionAlgorithm : uint8_t { BCRYPT, SHA256, SHA256_MULTIPLE };
+/// Need to be stable, auth durability depends on this
+enum class PasswordHashAlgorithm : uint8_t { BCRYPT = 0, SHA256 = 1, SHA256_MULTIPLE = 2 };
 
-/// @throw AuthException if unable to encrypt the password.
-std::string EncryptPassword(const std::string &password);
+void SetHashAlgorithm(std::string_view algo);
 
-/// @throw AuthException if unable to verify the password.
-bool VerifyPassword(const std::string &password, const std::string &hash);
+auto CurrentHashAlgorithm() -> PasswordHashAlgorithm;
+
+auto AsString(PasswordHashAlgorithm hash_algo) -> std::string_view;
+
+struct HashedPassword {
+  HashedPassword() = default;
+  HashedPassword(PasswordHashAlgorithm hash_algo, std::string password_hash)
+      : hash_algo{hash_algo}, password_hash{std::move(password_hash)} {}
+  HashedPassword(HashedPassword const &) = default;
+  HashedPassword(HashedPassword &&) = default;
+  HashedPassword &operator=(HashedPassword const &) = default;
+  HashedPassword &operator=(HashedPassword &&) = default;
+
+  friend bool operator==(HashedPassword const &, HashedPassword const &) = default;
+
+  bool VerifyPassword(const std::string &password);
+
+  bool IsSalted() const;
+
+  auto HashAlgo() const -> PasswordHashAlgorithm { return hash_algo; }
+
+  friend void to_json(nlohmann::json &j, const HashedPassword &p);
+  friend void from_json(const nlohmann::json &j, HashedPassword &p);
+
+ private:
+  PasswordHashAlgorithm hash_algo{PasswordHashAlgorithm::BCRYPT};
+  std::string password_hash{};
+};
+
+/// @throw AuthException if unable to hash the password.
+HashedPassword HashPassword(const std::string &password, std::optional<PasswordHashAlgorithm> override_algo = {});
 }  // namespace memgraph::auth

src/auth/models.cpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Licensed as a Memgraph Enterprise file under the Memgraph Enterprise
 // License (the "License"); by using this file, you agree to be bound by the terms of the License, and you may not use
@@ -9,7 +9,6 @@
 #include "auth/models.hpp"
 
 #include <cstdint>
-#include <regex>
 #include <utility>
 
 #include <gflags/gflags.h>
@@ -21,22 +20,26 @@
 #include "query/constants.hpp"
 #include "spdlog/spdlog.h"
 #include "utils/cast.hpp"
-#include "utils/logging.hpp"
-#include "utils/settings.hpp"
 #include "utils/string.hpp"
 
-// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
-DEFINE_bool(auth_password_permit_null, true, "Set to false to disable null passwords.");
-
-inline constexpr std::string_view default_password_regex = ".+";
-// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
-DEFINE_string(auth_password_strength_regex, default_password_regex.data(),
-              "The regular expression that should be used to match the entire "
-              "entered password to ensure its strength.");
-
 namespace memgraph::auth {
 namespace {
 
+constexpr auto kRoleName = "rolename";
+constexpr auto kPermissions = "permissions";
+constexpr auto kGrants = "grants";
+constexpr auto kDenies = "denies";
+constexpr auto kUsername = "username";
+constexpr auto kPasswordHash = "password_hash";
+
+#ifdef MG_ENTERPRISE
+constexpr auto kGlobalPermission = "global_permission";
+constexpr auto kFineGrainedAccessHandler = "fine_grained_access_handler";
+constexpr auto kAllowAll = "allow_all";
+constexpr auto kDefault = "default";
+constexpr auto kDatabases = "databases";
+#endif
+
 // Constant list of all available permissions.
 const std::vector<Permission> kPermissionsAll = {Permission::MATCH,
                                                  Permission::CREATE,
@@ -62,7 +65,8 @@ const std::vector<Permission> kPermissionsAll = {Permission::MATCH,
                                                  Permission::TRANSACTION_MANAGEMENT,
                                                  Permission::STORAGE_MODE,
                                                  Permission::MULTI_DATABASE_EDIT,
-                                                 Permission::MULTI_DATABASE_USE};
+                                                 Permission::MULTI_DATABASE_USE,
+                                                 Permission::COORDINATOR};
 
 }  // namespace
 
@@ -118,6 +122,8 @@ std::string PermissionToString(Permission permission) {
       return "MULTI_DATABASE_EDIT";
     case Permission::MULTI_DATABASE_USE:
       return "MULTI_DATABASE_USE";
+    case Permission::COORDINATOR:
+      return "COORDINATOR";
   }
 }
 
@@ -242,8 +248,9 @@ std::vector<Permission> Permissions::GetDenies() const {
 
 nlohmann::json Permissions::Serialize() const {
   nlohmann::json data = nlohmann::json::object();
-  data["grants"] = grants_;
-  data["denies"] = denies_;
+
+  data[kGrants] = grants_;
+  data[kDenies] = denies_;
   return data;
 }
 
@@ -251,10 +258,10 @@ Permissions Permissions::Deserialize(const nlohmann::json &data) {
   if (!data.is_object()) {
     throw AuthException("Couldn't load permissions data!");
   }
-  if (!data["grants"].is_number_unsigned() || !data["denies"].is_number_unsigned()) {
+  if (!data[kGrants].is_number_unsigned() || !data[kDenies].is_number_unsigned()) {
     throw AuthException("Couldn't load permissions data!");
   }
-  return Permissions{data["grants"], data["denies"]};
+  return Permissions{data[kGrants], data[kDenies]};
 }
 
 uint64_t Permissions::grants() const { return grants_; }
@@ -316,8 +323,8 @@ nlohmann::json FineGrainedAccessPermissions::Serialize() const {
     return {};
   }
   nlohmann::json data = nlohmann::json::object();
-  data["permissions"] = permissions_;
-  data["global_permission"] = global_permission_.has_value() ? global_permission_.value() : -1;
+  data[kPermissions] = permissions_;
+  data[kGlobalPermission] = global_permission_.has_value() ? global_permission_.value() : -1;
   return data;
 }
 
@@ -330,13 +337,13 @@ FineGrainedAccessPermissions FineGrainedAccessPermissions::Deserialize(const nlo
   }
   std::optional<uint64_t> global_permission;
 
-  if (data["global_permission"].empty() || data["global_permission"] == -1) {
+  if (data[kGlobalPermission].empty() || data[kGlobalPermission] == -1) {
     global_permission = std::nullopt;
   } else {
-    global_permission = data["global_permission"];
+    global_permission = data[kGlobalPermission];
   }
 
-  return FineGrainedAccessPermissions(data["permissions"], global_permission);
+  return FineGrainedAccessPermissions(data[kPermissions], global_permission);
 }
 
 const std::unordered_map<std::string, uint64_t> &FineGrainedAccessPermissions::GetPermissions() const {
@@ -442,13 +449,13 @@ const FineGrainedAccessPermissions &Role::GetFineGrainedAccessEdgeTypePermission
 
 nlohmann::json Role::Serialize() const {
   nlohmann::json data = nlohmann::json::object();
-  data["rolename"] = rolename_;
-  data["permissions"] = permissions_.Serialize();
+  data[kRoleName] = rolename_;
+  data[kPermissions] = permissions_.Serialize();
 #ifdef MG_ENTERPRISE
   if (memgraph::license::global_license_checker.IsEnterpriseValidFast()) {
-    data["fine_grained_access_handler"] = fine_grained_access_handler_.Serialize();
+    data[kFineGrainedAccessHandler] = fine_grained_access_handler_.Serialize();
   } else {
-    data["fine_grained_access_handler"] = {};
+    data[kFineGrainedAccessHandler] = {};
   }
 #endif
   return data;
@@ -458,21 +465,21 @@ Role Role::Deserialize(const nlohmann::json &data) {
   if (!data.is_object()) {
     throw AuthException("Couldn't load role data!");
   }
-  if (!data["rolename"].is_string() || !data["permissions"].is_object()) {
+  if (!data[kRoleName].is_string() || !data[kPermissions].is_object()) {
     throw AuthException("Couldn't load role data!");
   }
-  auto permissions = Permissions::Deserialize(data["permissions"]);
+  auto permissions = Permissions::Deserialize(data[kPermissions]);
 #ifdef MG_ENTERPRISE
   if (memgraph::license::global_license_checker.IsEnterpriseValidFast()) {
     FineGrainedAccessHandler fine_grained_access_handler;
     // We can have an empty fine_grained if the user was created without a valid license
-    if (data["fine_grained_access_handler"].is_object()) {
-      fine_grained_access_handler = FineGrainedAccessHandler::Deserialize(data["fine_grained_access_handler"]);
+    if (data[kFineGrainedAccessHandler].is_object()) {
+      fine_grained_access_handler = FineGrainedAccessHandler::Deserialize(data[kFineGrainedAccessHandler]);
     }
-    return {data["rolename"], permissions, std::move(fine_grained_access_handler)};
+    return {data[kRoleName], permissions, std::move(fine_grained_access_handler)};
   }
 #endif
-  return {data["rolename"], permissions};
+  return {data[kRoleName], permissions};
 }
 
 bool operator==(const Role &first, const Role &second) {
@@ -542,10 +549,10 @@ const std::string &Databases::GetDefault() const {
 
 nlohmann::json Databases::Serialize() const {
   nlohmann::json data = nlohmann::json::object();
-  data["grants"] = grants_dbs_;
-  data["denies"] = denies_dbs_;
-  data["allow_all"] = allow_all_;
-  data["default"] = default_db_;
+  data[kGrants] = grants_dbs_;
+  data[kDenies] = denies_dbs_;
+  data[kAllowAll] = allow_all_;
+  data[kDefault] = default_db_;
   return data;
 }
 
@@ -553,22 +560,22 @@ Databases Databases::Deserialize(const nlohmann::json &data) {
   if (!data.is_object()) {
     throw AuthException("Couldn't load database data!");
   }
-  if (!data["grants"].is_structured() || !data["denies"].is_structured() || !data["allow_all"].is_boolean() ||
-      !data["default"].is_string()) {
+  if (!data[kGrants].is_structured() || !data[kDenies].is_structured() || !data[kAllowAll].is_boolean() ||
+      !data[kDefault].is_string()) {
     throw AuthException("Couldn't load database data!");
   }
-  return {data["allow_all"], data["grants"], data["denies"], data["default"]};
+  return {data[kAllowAll], data[kGrants], data[kDenies], data[kDefault]};
 }
 #endif
 
 User::User() = default;
 
 User::User(const std::string &username) : username_(utils::ToLowerCase(username)) {}
-User::User(const std::string &username, std::string password_hash, const Permissions &permissions)
+User::User(const std::string &username, std::optional<HashedPassword> password_hash, const Permissions &permissions)
     : username_(utils::ToLowerCase(username)), password_hash_(std::move(password_hash)), permissions_(permissions) {}
 
 #ifdef MG_ENTERPRISE
-User::User(const std::string &username, std::string password_hash, const Permissions &permissions,
+User::User(const std::string &username, std::optional<HashedPassword> password_hash, const Permissions &permissions,
            FineGrainedAccessHandler fine_grained_access_handler, Databases db_access)
     : username_(utils::ToLowerCase(username)),
       password_hash_(std::move(password_hash)),
@@ -578,38 +585,16 @@ User::User(const std::string &username, std::string password_hash, const Permiss
 #endif
 
 bool User::CheckPassword(const std::string &password) {
-  if (password_hash_.empty()) return true;
-  return VerifyPassword(password, password_hash_);
+  return password_hash_ ? password_hash_->VerifyPassword(password) : true;
 }
 
-void User::UpdatePassword(const std::optional<std::string> &password) {
+void User::UpdatePassword(const std::optional<std::string> &password,
+                          std::optional<PasswordHashAlgorithm> algo_override) {
   if (!password) {
-    if (!FLAGS_auth_password_permit_null) {
-      throw AuthException("Null passwords aren't permitted!");
-    }
-    password_hash_ = "";
+    password_hash_.reset();
     return;
   }
-
-  if (FLAGS_auth_password_strength_regex != default_password_regex) {
-    if (const auto license_check_result = license::global_license_checker.IsEnterpriseValid(utils::global_settings);
-        license_check_result.HasError()) {
-      throw AuthException(
-          "Custom password regex is a Memgraph Enterprise feature. Please set the config "
-          "(\"--auth-password-strength-regex\") to its default value (\"{}\") or remove the flag.\n{}",
-          default_password_regex,
-          license::LicenseCheckErrorToString(license_check_result.GetError(), "password regex"));
-    }
-  }
-  std::regex re(FLAGS_auth_password_strength_regex);
-  if (!std::regex_match(*password, re)) {
-    throw AuthException(
-        "The user password doesn't conform to the required strength! Regex: "
-        "\"{}\"",
-        FLAGS_auth_password_strength_regex);
-  }
-
-  password_hash_ = EncryptPassword(*password);
+  password_hash_ = HashPassword(*password, algo_override);
 }
 
 void User::SetRole(const Role &role) { role_.emplace(role); }
@@ -626,27 +611,49 @@ Permissions User::GetPermissions() const {
 
 #ifdef MG_ENTERPRISE
 FineGrainedAccessPermissions User::GetFineGrainedAccessLabelPermissions() const {
+  return Merge(GetUserFineGrainedAccessLabelPermissions(), GetRoleFineGrainedAccessLabelPermissions());
+}
+
+FineGrainedAccessPermissions User::GetFineGrainedAccessEdgeTypePermissions() const {
+  return Merge(GetUserFineGrainedAccessEdgeTypePermissions(), GetRoleFineGrainedAccessEdgeTypePermissions());
+}
+
+FineGrainedAccessPermissions User::GetUserFineGrainedAccessEdgeTypePermissions() const {
   if (!memgraph::license::global_license_checker.IsEnterpriseValidFast()) {
     return FineGrainedAccessPermissions{};
   }
 
-  if (role_) {
-    return Merge(role()->fine_grained_access_handler().label_permissions(),
-                 fine_grained_access_handler_.label_permissions());
+  return fine_grained_access_handler_.edge_type_permissions();
+}
+
+FineGrainedAccessPermissions User::GetUserFineGrainedAccessLabelPermissions() const {
+  if (!memgraph::license::global_license_checker.IsEnterpriseValidFast()) {
+    return FineGrainedAccessPermissions{};
   }
 
   return fine_grained_access_handler_.label_permissions();
 }
 
-FineGrainedAccessPermissions User::GetFineGrainedAccessEdgeTypePermissions() const {
+FineGrainedAccessPermissions User::GetRoleFineGrainedAccessEdgeTypePermissions() const {
   if (!memgraph::license::global_license_checker.IsEnterpriseValidFast()) {
     return FineGrainedAccessPermissions{};
   }
+
   if (role_) {
-    return Merge(role()->fine_grained_access_handler().edge_type_permissions(),
-                 fine_grained_access_handler_.edge_type_permissions());
+    return role()->fine_grained_access_handler().edge_type_permissions();
   }
-  return fine_grained_access_handler_.edge_type_permissions();
+  return FineGrainedAccessPermissions{};
+}
+
+FineGrainedAccessPermissions User::GetRoleFineGrainedAccessLabelPermissions() const {
+  if (!memgraph::license::global_license_checker.IsEnterpriseValidFast()) {
+    return FineGrainedAccessPermissions{};
+  }
+
+  if (role_) {
+    return role()->fine_grained_access_handler().label_permissions();
+  }
+  return FineGrainedAccessPermissions{};
 }
 #endif
 
@@ -668,16 +675,20 @@ const Role *User::role() const {
 
 nlohmann::json User::Serialize() const {
   nlohmann::json data = nlohmann::json::object();
-  data["username"] = username_;
-  data["password_hash"] = password_hash_;
-  data["permissions"] = permissions_.Serialize();
+  data[kUsername] = username_;
+  if (password_hash_.has_value()) {
+    data[kPasswordHash] = *password_hash_;
+  } else {
+    data[kPasswordHash] = nullptr;
+  }
+  data[kPermissions] = permissions_.Serialize();
 #ifdef MG_ENTERPRISE
   if (memgraph::license::global_license_checker.IsEnterpriseValidFast()) {
-    data["fine_grained_access_handler"] = fine_grained_access_handler_.Serialize();
-    data["databases"] = database_access_.Serialize();
+    data[kFineGrainedAccessHandler] = fine_grained_access_handler_.Serialize();
+    data[kDatabases] = database_access_.Serialize();
   } else {
-    data["fine_grained_access_handler"] = {};
-    data["databases"] = {};
+    data[kFineGrainedAccessHandler] = {};
+    data[kDatabases] = {};
   }
 #endif
   // The role shouldn't be serialized here, it is stored as a foreign key.
@@ -688,15 +699,23 @@ User User::Deserialize(const nlohmann::json &data) {
   if (!data.is_object()) {
     throw AuthException("Couldn't load user data!");
   }
-  if (!data["username"].is_string() || !data["password_hash"].is_string() || !data["permissions"].is_object()) {
+  auto password_hash_json = data[kPasswordHash];
+  if (!data[kUsername].is_string() || !(password_hash_json.is_object() || password_hash_json.is_null()) ||
+      !data[kPermissions].is_object()) {
     throw AuthException("Couldn't load user data!");
   }
-  auto permissions = Permissions::Deserialize(data["permissions"]);
+
+  std::optional<HashedPassword> password_hash{};
+  if (password_hash_json.is_object()) {
+    password_hash = password_hash_json.get<HashedPassword>();
+  }
+
+  auto permissions = Permissions::Deserialize(data[kPermissions]);
 #ifdef MG_ENTERPRISE
   if (memgraph::license::global_license_checker.IsEnterpriseValidFast()) {
     Databases db_access;
-    if (data["databases"].is_structured()) {
-      db_access = Databases::Deserialize(data["databases"]);
+    if (data[kDatabases].is_structured()) {
+      db_access = Databases::Deserialize(data[kDatabases]);
     } else {
       // Back-compatibility
       spdlog::warn("User without specified database access. Given access to the default database.");
@@ -705,13 +724,13 @@ User User::Deserialize(const nlohmann::json &data) {
     }
     FineGrainedAccessHandler fine_grained_access_handler;
     // We can have an empty fine_grained if the user was created without a valid license
-    if (data["fine_grained_access_handler"].is_object()) {
-      fine_grained_access_handler = FineGrainedAccessHandler::Deserialize(data["fine_grained_access_handler"]);
+    if (data[kFineGrainedAccessHandler].is_object()) {
+      fine_grained_access_handler = FineGrainedAccessHandler::Deserialize(data[kFineGrainedAccessHandler]);
     }
-    return {data["username"], data["password_hash"], permissions, std::move(fine_grained_access_handler), db_access};
+    return {data[kUsername], std::move(password_hash), permissions, std::move(fine_grained_access_handler), db_access};
   }
 #endif
-  return {data["username"], data["password_hash"], permissions};
+  return {data[kUsername], std::move(password_hash), permissions};
 }
 
 bool operator==(const User &first, const User &second) {

src/auth/models.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Licensed as a Memgraph Enterprise file under the Memgraph Enterprise
 // License (the "License"); by using this file, you agree to be bound by the terms of the License, and you may not use
@@ -15,6 +15,7 @@
 
 #include <json/json.hpp>
 #include <utility>
+#include "crypto.hpp"
 #include "dbms/constants.hpp"
 #include "utils/logging.hpp"
 
@@ -48,6 +49,7 @@ enum class Permission : uint64_t {
   STORAGE_MODE = 1U << 22U,
   MULTI_DATABASE_EDIT = 1U << 23U,
   MULTI_DATABASE_USE  = 1U << 24U,
+  COORDINATOR  = 1U << 25U,
 };
 // clang-format on
 
@@ -205,6 +207,8 @@ bool operator==(const FineGrainedAccessHandler &first, const FineGrainedAccessHa
 
 class Role final {
  public:
+  Role() = default;
+
   explicit Role(const std::string &rolename);
   Role(const std::string &rolename, const Permissions &permissions);
 #ifdef MG_ENTERPRISE
@@ -331,9 +335,9 @@ class User final {
   User();
 
   explicit User(const std::string &username);
-  User(const std::string &username, std::string password_hash, const Permissions &permissions);
+  User(const std::string &username, std::optional<HashedPassword> password_hash, const Permissions &permissions);
 #ifdef MG_ENTERPRISE
-  User(const std::string &username, std::string password_hash, const Permissions &permissions,
+  User(const std::string &username, std::optional<HashedPassword> password_hash, const Permissions &permissions,
        FineGrainedAccessHandler fine_grained_access_handler, Databases db_access = {});
 #endif
   User(const User &) = default;
@@ -345,8 +349,18 @@ class User final {
   /// @throw AuthException if unable to verify the password.
   bool CheckPassword(const std::string &password);
 
+  bool UpgradeHash(const std::string password) {
+    if (!password_hash_) return false;
+    if (password_hash_->IsSalted()) return false;
+
+    auto const algo = password_hash_->HashAlgo();
+    UpdatePassword(password, algo);
+    return true;
+  }
+
   /// @throw AuthException if unable to set the password.
-  void UpdatePassword(const std::optional<std::string> &password = std::nullopt);
+  void UpdatePassword(const std::optional<std::string> &password = {},
+                      std::optional<PasswordHashAlgorithm> algo_override = std::nullopt);
 
   void SetRole(const Role &role);
 
@@ -357,6 +371,10 @@ class User final {
 #ifdef MG_ENTERPRISE
   FineGrainedAccessPermissions GetFineGrainedAccessLabelPermissions() const;
   FineGrainedAccessPermissions GetFineGrainedAccessEdgeTypePermissions() const;
+  FineGrainedAccessPermissions GetUserFineGrainedAccessLabelPermissions() const;
+  FineGrainedAccessPermissions GetUserFineGrainedAccessEdgeTypePermissions() const;
+  FineGrainedAccessPermissions GetRoleFineGrainedAccessLabelPermissions() const;
+  FineGrainedAccessPermissions GetRoleFineGrainedAccessEdgeTypePermissions() const;
   const FineGrainedAccessHandler &fine_grained_access_handler() const;
   FineGrainedAccessHandler &fine_grained_access_handler();
 #endif
@@ -381,7 +399,7 @@ class User final {
 
  private:
   std::string username_;
-  std::string password_hash_;
+  std::optional<HashedPassword> password_hash_;
   Permissions permissions_;
 #ifdef MG_ENTERPRISE
   FineGrainedAccessHandler fine_grained_access_handler_;

src/auth/replication_handlers.cpp

@@ -0,0 +1,170 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#include "auth/replication_handlers.hpp"
+
+#include "auth/auth.hpp"
+#include "auth/rpc.hpp"
+#include "license/license.hpp"
+
+namespace memgraph::auth {
+
+#ifdef MG_ENTERPRISE
+void UpdateAuthDataHandler(memgraph::system::ReplicaHandlerAccessToState &system_state_access, auth::SynchedAuth &auth,
+                           slk::Reader *req_reader, slk::Builder *res_builder) {
+  replication::UpdateAuthDataReq req;
+  memgraph::slk::Load(&req, req_reader);
+
+  using memgraph::replication::UpdateAuthDataRes;
+  UpdateAuthDataRes res(false);
+
+  // Note: No need to check epoch, recovery mechanism is done by a full uptodate snapshot
+  //       of the set of databases. Hence no history exists to maintain regarding epoch change.
+  //       If MAIN has changed we need to check this new group_timestamp is consistent with
+  //       what we have so far.
+
+  if (req.expected_group_timestamp != system_state_access.LastCommitedTS()) {
+    spdlog::debug("UpdateAuthDataHandler: bad expected timestamp {},{}", req.expected_group_timestamp,
+                  system_state_access.LastCommitedTS());
+    memgraph::slk::Save(res, res_builder);
+    return;
+  }
+
+  try {
+    // Update
+    if (req.user) auth->SaveUser(*req.user);
+    if (req.role) auth->SaveRole(*req.role);
+    // Success
+    system_state_access.SetLastCommitedTS(req.new_group_timestamp);
+    res = UpdateAuthDataRes(true);
+    spdlog::debug("UpdateAuthDataHandler: SUCCESS updated LCTS to {}", req.new_group_timestamp);
+  } catch (const auth::AuthException & /* not used */) {
+    // Failure
+  }
+
+  memgraph::slk::Save(res, res_builder);
+}
+
+void DropAuthDataHandler(memgraph::system::ReplicaHandlerAccessToState &system_state_access, auth::SynchedAuth &auth,
+                         slk::Reader *req_reader, slk::Builder *res_builder) {
+  replication::DropAuthDataReq req;
+  memgraph::slk::Load(&req, req_reader);
+
+  using memgraph::replication::DropAuthDataRes;
+  DropAuthDataRes res(false);
+
+  // Note: No need to check epoch, recovery mechanism is done by a full uptodate snapshot
+  //       of the set of databases. Hence no history exists to maintain regarding epoch change.
+  //       If MAIN has changed we need to check this new group_timestamp is consistent with
+  //       what we have so far.
+
+  if (req.expected_group_timestamp != system_state_access.LastCommitedTS()) {
+    spdlog::debug("DropAuthDataHandler: bad expected timestamp {},{}", req.expected_group_timestamp,
+                  system_state_access.LastCommitedTS());
+    memgraph::slk::Save(res, res_builder);
+    return;
+  }
+
+  try {
+    // Remove
+    switch (req.type) {
+      case replication::DropAuthDataReq::DataType::USER:
+        auth->RemoveUser(req.name);
+        break;
+      case replication::DropAuthDataReq::DataType::ROLE:
+        auth->RemoveRole(req.name);
+        break;
+    }
+    // Success
+    system_state_access.SetLastCommitedTS(req.new_group_timestamp);
+    res = DropAuthDataRes(true);
+    spdlog::debug("DropAuthDataHandler: SUCCESS updated LCTS to {}", req.new_group_timestamp);
+  } catch (const auth::AuthException & /* not used */) {
+    // Failure
+  }
+
+  memgraph::slk::Save(res, res_builder);
+}
+
+bool SystemRecoveryHandler(auth::SynchedAuth &auth, auth::Auth::Config auth_config,
+                           const std::vector<auth::User> &users, const std::vector<auth::Role> &roles) {
+  return auth.WithLock([&](auto &locked_auth) {
+    // Update config
+    locked_auth.SetConfig(std::move(auth_config));
+    // Get all current users
+    auto old_users = locked_auth.AllUsernames();
+    // Save incoming users
+    for (const auto &user : users) {
+      // Missing users
+      try {
+        locked_auth.SaveUser(user);
+      } catch (const auth::AuthException &) {
+        spdlog::debug("SystemRecoveryHandler: Failed to save user");
+        return false;
+      }
+      const auto it = std::find(old_users.begin(), old_users.end(), user.username());
+      if (it != old_users.end()) old_users.erase(it);
+    }
+    // Delete all the leftover users
+    for (const auto &user : old_users) {
+      if (!locked_auth.RemoveUser(user)) {
+        spdlog::debug("SystemRecoveryHandler: Failed to remove user \"{}\".", user);
+        return false;
+      }
+    }
+
+    // Roles are only supported with a license
+    if (license::global_license_checker.IsEnterpriseValidFast()) {
+      // Get all current roles
+      auto old_roles = locked_auth.AllRolenames();
+      // Save incoming users
+      for (const auto &role : roles) {
+        // Missing users
+        try {
+          locked_auth.SaveRole(role);
+        } catch (const auth::AuthException &) {
+          spdlog::debug("SystemRecoveryHandler: Failed to save user");
+          return false;
+        }
+        const auto it = std::find(old_roles.begin(), old_roles.end(), role.rolename());
+        if (it != old_roles.end()) old_roles.erase(it);
+      }
+      // Delete all the leftover users
+      for (const auto &role : old_roles) {
+        if (!locked_auth.RemoveRole(role)) {
+          spdlog::debug("SystemRecoveryHandler: Failed to remove user \"{}\".", role);
+          return false;
+        }
+      }
+    }
+
+    // Success
+    return true;
+  });
+}
+
+void Register(replication::RoleReplicaData const &data, system::ReplicaHandlerAccessToState &system_state_access,
+              auth::SynchedAuth &auth) {
+  // NOTE: Register even without license as the user could add a license at run-time
+  data.server->rpc_server_.Register<replication::UpdateAuthDataRpc>(
+      [system_state_access, &auth](auto *req_reader, auto *res_builder) mutable {
+        spdlog::debug("Received UpdateAuthDataRpc");
+        UpdateAuthDataHandler(system_state_access, auth, req_reader, res_builder);
+      });
+  data.server->rpc_server_.Register<replication::DropAuthDataRpc>(
+      [system_state_access, &auth](auto *req_reader, auto *res_builder) mutable {
+        spdlog::debug("Received DropAuthDataRpc");
+        DropAuthDataHandler(system_state_access, auth, req_reader, res_builder);
+      });
+}
+#endif
+
+}  // namespace memgraph::auth

src/auth/replication_handlers.hpp

@@ -0,0 +1,31 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#include "auth/auth.hpp"
+#include "replication/state.hpp"
+#include "slk/streams.hpp"
+#include "system/state.hpp"
+
+namespace memgraph::auth {
+#ifdef MG_ENTERPRISE
+void UpdateAuthDataHandler(system::ReplicaHandlerAccessToState &system_state_access, auth::SynchedAuth &auth,
+                           slk::Reader *req_reader, slk::Builder *res_builder);
+void DropAuthDataHandler(system::ReplicaHandlerAccessToState &system_state_access, auth::SynchedAuth &auth,
+                         slk::Reader *req_reader, slk::Builder *res_builder);
+
+bool SystemRecoveryHandler(auth::SynchedAuth &auth, auth::Auth::Config auth_config,
+                           const std::vector<auth::User> &users, const std::vector<auth::Role> &roles);
+void Register(replication::RoleReplicaData const &data, system::ReplicaHandlerAccessToState &system_state_access,
+              auth::SynchedAuth &auth);
+#endif
+}  // namespace memgraph::auth

src/auth/rpc.cpp

@@ -0,0 +1,178 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#include "auth/rpc.hpp"
+
+#include <json/json.hpp>
+#include "auth/auth.hpp"
+#include "slk/serialization.hpp"
+#include "slk/streams.hpp"
+#include "utils/enum.hpp"
+
+namespace memgraph::slk {
+
+// Serialize code for auth::Role
+void Save(const auth::Role &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self.Serialize().dump(), builder);
+}
+namespace {
+auth::Role LoadAuthRole(memgraph::slk::Reader *reader) {
+  std::string tmp;
+  memgraph::slk::Load(&tmp, reader);
+  const auto json = nlohmann::json::parse(tmp);
+  return memgraph::auth::Role::Deserialize(json);
+}
+}  // namespace
+// Deserialize code for auth::Role
+void Load(auth::Role *self, memgraph::slk::Reader *reader) { *self = LoadAuthRole(reader); }
+// Special case for optional<Role>
+template <>
+inline void Load<auth::Role>(std::optional<auth::Role> *obj, Reader *reader) {
+  bool exists = false;
+  Load(&exists, reader);
+  if (exists) {
+    obj->emplace(LoadAuthRole(reader));
+  } else {
+    *obj = std::nullopt;
+  }
+}
+
+// Serialize code for auth::User
+void Save(const auth::User &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self.Serialize().dump(), builder);
+  std::optional<auth::Role> role{};
+  if (const auto *role_ptr = self.role(); role_ptr) {
+    role.emplace(*role_ptr);
+  }
+  memgraph::slk::Save(role, builder);
+}
+// Deserialize code for auth::User
+void Load(auth::User *self, memgraph::slk::Reader *reader) {
+  std::string tmp;
+  memgraph::slk::Load(&tmp, reader);
+  const auto json = nlohmann::json::parse(tmp);
+  *self = memgraph::auth::User::Deserialize(json);
+  std::optional<auth::Role> role{};
+  memgraph::slk::Load(&role, reader);
+  if (role)
+    self->SetRole(*role);
+  else
+    self->ClearRole();
+}
+
+// Serialize code for auth::Auth::Config
+void Save(const auth::Auth::Config &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self.name_regex_str, builder);
+  memgraph::slk::Save(self.password_regex_str, builder);
+  memgraph::slk::Save(self.password_permit_null, builder);
+}
+// Deserialize code for auth::Auth::Config
+void Load(auth::Auth::Config *self, memgraph::slk::Reader *reader) {
+  std::string name_regex_str{};
+  std::string password_regex_str{};
+  bool password_permit_null{};
+
+  memgraph::slk::Load(&name_regex_str, reader);
+  memgraph::slk::Load(&password_regex_str, reader);
+  memgraph::slk::Load(&password_permit_null, reader);
+
+  *self = auth::Auth::Config{std::move(name_regex_str), std::move(password_regex_str), password_permit_null};
+}
+
+// Serialize code for UpdateAuthDataReq
+void Save(const memgraph::replication::UpdateAuthDataReq &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self.epoch_id, builder);
+  memgraph::slk::Save(self.expected_group_timestamp, builder);
+  memgraph::slk::Save(self.new_group_timestamp, builder);
+  memgraph::slk::Save(self.user, builder);
+  memgraph::slk::Save(self.role, builder);
+}
+void Load(memgraph::replication::UpdateAuthDataReq *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(&self->epoch_id, reader);
+  memgraph::slk::Load(&self->expected_group_timestamp, reader);
+  memgraph::slk::Load(&self->new_group_timestamp, reader);
+  memgraph::slk::Load(&self->user, reader);
+  memgraph::slk::Load(&self->role, reader);
+}
+
+// Serialize code for UpdateAuthDataRes
+void Save(const memgraph::replication::UpdateAuthDataRes &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self.success, builder);
+}
+void Load(memgraph::replication::UpdateAuthDataRes *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(&self->success, reader);
+}
+
+// Serialize code for DropAuthDataReq
+void Save(const memgraph::replication::DropAuthDataReq &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self.epoch_id, builder);
+  memgraph::slk::Save(self.expected_group_timestamp, builder);
+  memgraph::slk::Save(self.new_group_timestamp, builder);
+  memgraph::slk::Save(utils::EnumToNum<2, uint8_t>(self.type), builder);
+  memgraph::slk::Save(self.name, builder);
+}
+void Load(memgraph::replication::DropAuthDataReq *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(&self->epoch_id, reader);
+  memgraph::slk::Load(&self->expected_group_timestamp, reader);
+  memgraph::slk::Load(&self->new_group_timestamp, reader);
+  uint8_t type_tmp = 0;
+  memgraph::slk::Load(&type_tmp, reader);
+  if (!utils::NumToEnum<2>(type_tmp, self->type)) {
+    throw SlkReaderException("Unexpected result line:{}!", __LINE__);
+  }
+  memgraph::slk::Load(&self->name, reader);
+}
+
+// Serialize code for DropAuthDataRes
+void Save(const memgraph::replication::DropAuthDataRes &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self.success, builder);
+}
+void Load(memgraph::replication::DropAuthDataRes *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(&self->success, reader);
+}
+
+}  // namespace memgraph::slk
+
+namespace memgraph::replication {
+
+constexpr utils::TypeInfo UpdateAuthDataReq::kType{utils::TypeId::REP_UPDATE_AUTH_DATA_REQ, "UpdateAuthDataReq",
+                                                   nullptr};
+
+constexpr utils::TypeInfo UpdateAuthDataRes::kType{utils::TypeId::REP_UPDATE_AUTH_DATA_RES, "UpdateAuthDataRes",
+                                                   nullptr};
+
+constexpr utils::TypeInfo DropAuthDataReq::kType{utils::TypeId::REP_DROP_AUTH_DATA_REQ, "DropAuthDataReq", nullptr};
+
+constexpr utils::TypeInfo DropAuthDataRes::kType{utils::TypeId::REP_DROP_AUTH_DATA_RES, "DropAuthDataRes", nullptr};
+
+void UpdateAuthDataReq::Save(const UpdateAuthDataReq &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self, builder);
+}
+void UpdateAuthDataReq::Load(UpdateAuthDataReq *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(self, reader);
+}
+void UpdateAuthDataRes::Save(const UpdateAuthDataRes &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self, builder);
+}
+void UpdateAuthDataRes::Load(UpdateAuthDataRes *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(self, reader);
+}
+
+void DropAuthDataReq::Save(const DropAuthDataReq &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self, builder);
+}
+void DropAuthDataReq::Load(DropAuthDataReq *self, memgraph::slk::Reader *reader) { memgraph::slk::Load(self, reader); }
+void DropAuthDataRes::Save(const DropAuthDataRes &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self, builder);
+}
+void DropAuthDataRes::Load(DropAuthDataRes *self, memgraph::slk::Reader *reader) { memgraph::slk::Load(self, reader); }
+
+}  // namespace memgraph::replication

src/auth/rpc.hpp

@@ -0,0 +1,119 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#include <optional>
+
+#include "auth/auth.hpp"
+#include "auth/models.hpp"
+#include "rpc/messages.hpp"
+#include "slk/streams.hpp"
+
+namespace memgraph::replication {
+
+struct UpdateAuthDataReq {
+  static const utils::TypeInfo kType;
+  static const utils::TypeInfo &GetTypeInfo() { return kType; }
+
+  static void Load(UpdateAuthDataReq *self, memgraph::slk::Reader *reader);
+  static void Save(const UpdateAuthDataReq &self, memgraph::slk::Builder *builder);
+  UpdateAuthDataReq() = default;
+  UpdateAuthDataReq(std::string epoch_id, uint64_t expected_ts, uint64_t new_ts, auth::User user)
+      : epoch_id{std::move(epoch_id)},
+        expected_group_timestamp{expected_ts},
+        new_group_timestamp{new_ts},
+        user{std::move(user)} {}
+  UpdateAuthDataReq(std::string epoch_id, uint64_t expected_ts, uint64_t new_ts, auth::Role role)
+      : epoch_id{std::move(epoch_id)},
+        expected_group_timestamp{expected_ts},
+        new_group_timestamp{new_ts},
+        role{std::move(role)} {}
+
+  std::string epoch_id;
+  uint64_t expected_group_timestamp;
+  uint64_t new_group_timestamp;
+  std::optional<auth::User> user;
+  std::optional<auth::Role> role;
+};
+
+struct UpdateAuthDataRes {
+  static const utils::TypeInfo kType;
+  static const utils::TypeInfo &GetTypeInfo() { return kType; }
+
+  static void Load(UpdateAuthDataRes *self, memgraph::slk::Reader *reader);
+  static void Save(const UpdateAuthDataRes &self, memgraph::slk::Builder *builder);
+  UpdateAuthDataRes() = default;
+  explicit UpdateAuthDataRes(bool success) : success{success} {}
+
+  bool success;
+};
+
+using UpdateAuthDataRpc = rpc::RequestResponse<UpdateAuthDataReq, UpdateAuthDataRes>;
+
+struct DropAuthDataReq {
+  static const utils::TypeInfo kType;
+  static const utils::TypeInfo &GetTypeInfo() { return kType; }
+
+  static void Load(DropAuthDataReq *self, memgraph::slk::Reader *reader);
+  static void Save(const DropAuthDataReq &self, memgraph::slk::Builder *builder);
+  DropAuthDataReq() = default;
+
+  enum class DataType { USER, ROLE };
+
+  DropAuthDataReq(std::string epoch_id, uint64_t expected_ts, uint64_t new_ts, DataType type, std::string_view name)
+      : epoch_id{std::move(epoch_id)},
+        expected_group_timestamp{expected_ts},
+        new_group_timestamp{new_ts},
+        type{type},
+        name{name} {}
+
+  std::string epoch_id;
+  uint64_t expected_group_timestamp;
+  uint64_t new_group_timestamp;
+  DataType type;
+  std::string name;
+};
+
+struct DropAuthDataRes {
+  static const utils::TypeInfo kType;
+  static const utils::TypeInfo &GetTypeInfo() { return kType; }
+
+  static void Load(DropAuthDataRes *self, memgraph::slk::Reader *reader);
+  static void Save(const DropAuthDataRes &self, memgraph::slk::Builder *builder);
+  DropAuthDataRes() = default;
+  explicit DropAuthDataRes(bool success) : success{success} {}
+
+  bool success;
+};
+
+using DropAuthDataRpc = rpc::RequestResponse<DropAuthDataReq, DropAuthDataRes>;
+
+}  // namespace memgraph::replication
+
+namespace memgraph::slk {
+
+void Save(const auth::Role &self, memgraph::slk::Builder *builder);
+void Load(auth::Role *self, memgraph::slk::Reader *reader);
+void Save(const auth::User &self, memgraph::slk::Builder *builder);
+void Load(auth::User *self, memgraph::slk::Reader *reader);
+void Save(const auth::Auth::Config &self, memgraph::slk::Builder *builder);
+void Load(auth::Auth::Config *self, memgraph::slk::Reader *reader);
+
+void Save(const memgraph::replication::UpdateAuthDataRes &self, memgraph::slk::Builder *builder);
+void Load(memgraph::replication::UpdateAuthDataRes *self, memgraph::slk::Reader *reader);
+void Save(const memgraph::replication::UpdateAuthDataReq & /*self*/, memgraph::slk::Builder * /*builder*/);
+void Load(memgraph::replication::UpdateAuthDataReq * /*self*/, memgraph::slk::Reader * /*reader*/);
+void Save(const memgraph::replication::DropAuthDataRes &self, memgraph::slk::Builder *builder);
+void Load(memgraph::replication::DropAuthDataRes *self, memgraph::slk::Reader *reader);
+void Save(const memgraph::replication::DropAuthDataReq & /*self*/, memgraph::slk::Builder * /*builder*/);
+void Load(memgraph::replication::DropAuthDataReq * /*self*/, memgraph::slk::Reader * /*reader*/);
+}  // namespace memgraph::slk

src/communication/websocket/auth.hpp

@@ -1,4 +1,4 @@
-// Copyright 2022 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -14,8 +14,6 @@
 #include <string>
 
 #include "auth/auth.hpp"
-#include "utils/spin_lock.hpp"
-#include "utils/synchronized.hpp"
 
 namespace memgraph::communication::websocket {
 
@@ -30,7 +28,7 @@ class AuthenticationInterface {
 
 class SafeAuth : public AuthenticationInterface {
  public:
-  explicit SafeAuth(utils::Synchronized<auth::Auth, utils::WritePrioritizedRWLock> *auth) : auth_{auth} {}
+  explicit SafeAuth(auth::SynchedAuth *auth) : auth_{auth} {}
 
   bool Authenticate(const std::string &username, const std::string &password) const override;
 
@@ -39,6 +37,6 @@ class SafeAuth : public AuthenticationInterface {
   bool HasAnyUsers() const override;
 
  private:
-  utils::Synchronized<auth::Auth, utils::WritePrioritizedRWLock> *auth_;
+  auth::SynchedAuth *auth_;
 };
 }  // namespace memgraph::communication::websocket

src/coordination/CMakeLists.txt

@@ -0,0 +1,31 @@
+add_library(mg-coordination STATIC)
+add_library(mg::coordination ALIAS mg-coordination)
+target_sources(mg-coordination
+        PUBLIC
+        include/coordination/coordinator_client.hpp
+        include/coordination/coordinator_state.hpp
+        include/coordination/coordinator_rpc.hpp
+        include/coordination/coordinator_server.hpp
+        include/coordination/coordinator_config.hpp
+        include/coordination/coordinator_exceptions.hpp
+        include/coordination/coordinator_instance.hpp
+        include/coordination/coordinator_slk.hpp
+        include/coordination/coordinator_data.hpp
+        include/coordination/constants.hpp
+        include/coordination/coordinator_cluster_config.hpp
+        include/coordination/coordinator_handlers.hpp
+
+        PRIVATE
+        coordinator_client.cpp
+        coordinator_state.cpp
+        coordinator_rpc.cpp
+        coordinator_server.cpp
+        coordinator_data.cpp
+        coordinator_instance.cpp
+        coordinator_handlers.cpp
+)
+target_include_directories(mg-coordination PUBLIC include)
+
+target_link_libraries(mg-coordination
+    PUBLIC mg::utils mg::rpc mg::slk mg::io mg::repl_coord_glue lib::rangev3 nuraft mg-replication_handler
+)

src/coordination/coordinator_client.cpp

@@ -0,0 +1,105 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#ifdef MG_ENTERPRISE
+
+#include "coordination/coordinator_client.hpp"
+
+#include "coordination/coordinator_config.hpp"
+#include "coordination/coordinator_rpc.hpp"
+#include "replication_coordination_glue/messages.hpp"
+
+namespace memgraph::coordination {
+
+namespace {
+auto CreateClientContext(memgraph::coordination::CoordinatorClientConfig const &config)
+    -> communication::ClientContext {
+  return (config.ssl) ? communication::ClientContext{config.ssl->key_file, config.ssl->cert_file}
+                      : communication::ClientContext{};
+}
+}  // namespace
+
+CoordinatorClient::CoordinatorClient(CoordinatorData *coord_data, CoordinatorClientConfig config,
+                                     HealthCheckCallback succ_cb, HealthCheckCallback fail_cb)
+    : rpc_context_{CreateClientContext(config)},
+      rpc_client_{io::network::Endpoint(io::network::Endpoint::needs_resolving, config.ip_address, config.port),
+                  &rpc_context_},
+      config_{std::move(config)},
+      coord_data_{coord_data},
+      succ_cb_{std::move(succ_cb)},
+      fail_cb_{std::move(fail_cb)} {}
+
+auto CoordinatorClient::InstanceName() const -> std::string { return config_.instance_name; }
+auto CoordinatorClient::SocketAddress() const -> std::string { return rpc_client_.Endpoint().SocketAddress(); }
+
+void CoordinatorClient::StartFrequentCheck() {
+  MG_ASSERT(config_.health_check_frequency_sec > std::chrono::seconds(0),
+            "Health check frequency must be greater than 0");
+
+  instance_checker_.Run(
+      config_.instance_name, config_.health_check_frequency_sec, [this, instance_name = config_.instance_name] {
+        try {
+          spdlog::trace("Sending frequent heartbeat to machine {} on {}", instance_name,
+                        rpc_client_.Endpoint().SocketAddress());
+          {  // NOTE: This is intentionally scoped so that stream lock could get released.
+            auto stream{rpc_client_.Stream<memgraph::replication_coordination_glue::FrequentHeartbeatRpc>()};
+            stream.AwaitResponse();
+          }
+          succ_cb_(coord_data_, instance_name);
+        } catch (rpc::RpcFailedException const &) {
+          fail_cb_(coord_data_, instance_name);
+        }
+      });
+}
+
+void CoordinatorClient::StopFrequentCheck() { instance_checker_.Stop(); }
+void CoordinatorClient::PauseFrequentCheck() { instance_checker_.Pause(); }
+void CoordinatorClient::ResumeFrequentCheck() { instance_checker_.Resume(); }
+
+auto CoordinatorClient::SetCallbacks(HealthCheckCallback succ_cb, HealthCheckCallback fail_cb) -> void {
+  succ_cb_ = std::move(succ_cb);
+  fail_cb_ = std::move(fail_cb);
+}
+
+auto CoordinatorClient::ReplicationClientInfo() const -> ReplClientInfo { return config_.replication_client_info; }
+
+auto CoordinatorClient::SendPromoteReplicaToMainRpc(ReplicationClientsInfo replication_clients_info) const -> bool {
+  try {
+    auto stream{rpc_client_.Stream<PromoteReplicaToMainRpc>(std::move(replication_clients_info))};
+    if (!stream.AwaitResponse().success) {
+      spdlog::error("Failed to receive successful RPC failover response!");
+      return false;
+    }
+    return true;
+  } catch (rpc::RpcFailedException const &) {
+    spdlog::error("RPC error occurred while sending failover RPC!");
+  }
+  return false;
+}
+
+auto CoordinatorClient::DemoteToReplica() const -> bool {
+  auto const &instance_name = config_.instance_name;
+  try {
+    auto stream{rpc_client_.Stream<DemoteMainToReplicaRpc>(config_.replication_client_info)};
+    if (!stream.AwaitResponse().success) {
+      spdlog::error("Failed to receive successful RPC response for setting instance {} to replica!", instance_name);
+      return false;
+    }
+    spdlog::info("Sent request RPC from coordinator to instance to set it as replica!");
+    return true;
+  } catch (rpc::RpcFailedException const &) {
+    spdlog::error("Failed to set instance {} to replica!", instance_name);
+  }
+  return false;
+}
+
+}  // namespace memgraph::coordination
+#endif

src/coordination/coordinator_data.cpp

@@ -0,0 +1,199 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#include "coordination/coordinator_instance.hpp"
+#include "coordination/register_main_replica_coordinator_status.hpp"
+#ifdef MG_ENTERPRISE
+
+#include "coordination/coordinator_data.hpp"
+
+#include <range/v3/view.hpp>
+#include <shared_mutex>
+#include "libnuraft/nuraft.hxx"
+
+namespace memgraph::coordination {
+
+CoordinatorData::CoordinatorData() {
+  auto find_instance = [](CoordinatorData *coord_data, std::string_view instance_name) -> CoordinatorInstance & {
+    auto instance = std::ranges::find_if(
+        coord_data->registered_instances_,
+        [instance_name](CoordinatorInstance const &instance) { return instance.InstanceName() == instance_name; });
+
+    MG_ASSERT(instance != coord_data->registered_instances_.end(), "Instance {} not found during callback!",
+              instance_name);
+    return *instance;
+  };
+
+  replica_succ_cb_ = [find_instance](CoordinatorData *coord_data, std::string_view instance_name) -> void {
+    auto lock = std::lock_guard{coord_data->coord_data_lock_};
+    spdlog::trace("Instance {} performing replica successful callback", instance_name);
+    find_instance(coord_data, instance_name).OnSuccessPing();
+  };
+
+  replica_fail_cb_ = [find_instance](CoordinatorData *coord_data, std::string_view instance_name) -> void {
+    auto lock = std::lock_guard{coord_data->coord_data_lock_};
+    spdlog::trace("Instance {} performing replica failure callback", instance_name);
+    find_instance(coord_data, instance_name).OnFailPing();
+  };
+
+  main_succ_cb_ = [find_instance](CoordinatorData *coord_data, std::string_view instance_name) -> void {
+    auto lock = std::lock_guard{coord_data->coord_data_lock_};
+    spdlog::trace("Instance {} performing main successful callback", instance_name);
+
+    auto &instance = find_instance(coord_data, instance_name);
+
+    if (instance.IsAlive() || !coord_data->ClusterHasAliveMain_()) {
+      instance.OnSuccessPing();
+      return;
+    }
+
+    bool const demoted = instance.DemoteToReplica(coord_data->replica_succ_cb_, coord_data->replica_fail_cb_);
+    if (demoted) {
+      instance.OnSuccessPing();
+      spdlog::info("Instance {} demoted to replica", instance_name);
+    } else {
+      spdlog::error("Instance {} failed to become replica", instance_name);
+    }
+  };
+
+  main_fail_cb_ = [find_instance](CoordinatorData *coord_data, std::string_view instance_name) -> void {
+    auto lock = std::lock_guard{coord_data->coord_data_lock_};
+    spdlog::trace("Instance {} performing main failure callback", instance_name);
+    find_instance(coord_data, instance_name).OnFailPing();
+
+    if (!coord_data->ClusterHasAliveMain_()) {
+      spdlog::info("Cluster without main instance, trying automatic failover");
+      coord_data->TryFailover();
+    }
+  };
+}
+
+auto CoordinatorData::ClusterHasAliveMain_() const -> bool {
+  auto const alive_main = [](CoordinatorInstance const &instance) { return instance.IsMain() && instance.IsAlive(); };
+  return std::ranges::any_of(registered_instances_, alive_main);
+}
+
+auto CoordinatorData::TryFailover() -> void {
+  auto replica_instances = registered_instances_ | ranges::views::filter(&CoordinatorInstance::IsReplica);
+
+  auto chosen_replica_instance = std::ranges::find_if(replica_instances, &CoordinatorInstance::IsAlive);
+  if (chosen_replica_instance == replica_instances.end()) {
+    spdlog::warn("Failover failed since all replicas are down!");
+    return;
+  }
+
+  chosen_replica_instance->PauseFrequentCheck();
+  utils::OnScopeExit scope_exit{[&chosen_replica_instance] { chosen_replica_instance->ResumeFrequentCheck(); }};
+
+  std::vector<ReplClientInfo> repl_clients_info;
+  repl_clients_info.reserve(std::ranges::distance(replica_instances));
+
+  auto const not_chosen_replica_instance = [&chosen_replica_instance](CoordinatorInstance const &instance) {
+    return instance != *chosen_replica_instance;
+  };
+
+  std::ranges::transform(registered_instances_ | ranges::views::filter(not_chosen_replica_instance),
+                         std::back_inserter(repl_clients_info),
+                         [](const CoordinatorInstance &instance) { return instance.ReplicationClientInfo(); });
+
+  if (!chosen_replica_instance->PromoteToMain(std::move(repl_clients_info), main_succ_cb_, main_fail_cb_)) {
+    spdlog::warn("Failover failed since promoting replica to main failed!");
+    return;
+  }
+  spdlog::info("Failover successful! Instance {} promoted to main.", chosen_replica_instance->InstanceName());
+}
+
+auto CoordinatorData::ShowInstances() const -> std::vector<CoordinatorInstanceStatus> {
+  std::vector<CoordinatorInstanceStatus> instances_status;
+  instances_status.reserve(registered_instances_.size());
+
+  auto const stringify_repl_role = [](CoordinatorInstance const &instance) -> std::string {
+    if (!instance.IsAlive()) return "unknown";
+    if (instance.IsMain()) return "main";
+    return "replica";
+  };
+
+  auto const instance_to_status =
+      [&stringify_repl_role](CoordinatorInstance const &instance) -> CoordinatorInstanceStatus {
+    return {.instance_name = instance.InstanceName(),
+            .socket_address = instance.SocketAddress(),
+            .replication_role = stringify_repl_role(instance),
+            .is_alive = instance.IsAlive()};
+  };
+
+  {
+    auto lock = std::shared_lock{coord_data_lock_};
+    std::ranges::transform(registered_instances_, std::back_inserter(instances_status), instance_to_status);
+  }
+
+  return instances_status;
+}
+
+auto CoordinatorData::SetInstanceToMain(std::string instance_name) -> SetInstanceToMainCoordinatorStatus {
+  auto lock = std::lock_guard{coord_data_lock_};
+
+  auto const is_new_main = [&instance_name](CoordinatorInstance const &instance) {
+    return instance.InstanceName() == instance_name;
+  };
+  auto new_main = std::ranges::find_if(registered_instances_, is_new_main);
+
+  if (new_main == registered_instances_.end()) {
+    spdlog::error("Instance {} not registered. Please register it using REGISTER INSTANCE {}", instance_name,
+                  instance_name);
+    return SetInstanceToMainCoordinatorStatus::NO_INSTANCE_WITH_NAME;
+  }
+
+  new_main->PauseFrequentCheck();
+  utils::OnScopeExit scope_exit{[&new_main] { new_main->ResumeFrequentCheck(); }};
+
+  ReplicationClientsInfo repl_clients_info;
+  repl_clients_info.reserve(registered_instances_.size() - 1);
+
+  auto const is_not_new_main = [&instance_name](CoordinatorInstance const &instance) {
+    return instance.InstanceName() != instance_name;
+  };
+  std::ranges::transform(registered_instances_ | ranges::views::filter(is_not_new_main),
+                         std::back_inserter(repl_clients_info),
+                         [](const CoordinatorInstance &instance) { return instance.ReplicationClientInfo(); });
+
+  if (!new_main->PromoteToMain(std::move(repl_clients_info), main_succ_cb_, main_fail_cb_)) {
+    return SetInstanceToMainCoordinatorStatus::COULD_NOT_PROMOTE_TO_MAIN;
+  }
+
+  spdlog::info("Instance {} promoted to main", instance_name);
+  return SetInstanceToMainCoordinatorStatus::SUCCESS;
+}
+
+auto CoordinatorData::RegisterInstance(CoordinatorClientConfig config) -> RegisterInstanceCoordinatorStatus {
+  auto lock = std::lock_guard{coord_data_lock_};
+  if (std::ranges::any_of(registered_instances_, [&config](CoordinatorInstance const &instance) {
+        return instance.InstanceName() == config.instance_name;
+      })) {
+    return RegisterInstanceCoordinatorStatus::NAME_EXISTS;
+  }
+
+  if (std::ranges::any_of(registered_instances_, [&config](CoordinatorInstance const &instance) {
+        return instance.SocketAddress() == config.SocketAddress();
+      })) {
+    return RegisterInstanceCoordinatorStatus::ENDPOINT_EXISTS;
+  }
+
+  try {
+    registered_instances_.emplace_back(this, std::move(config), replica_succ_cb_, replica_fail_cb_);
+    return RegisterInstanceCoordinatorStatus::SUCCESS;
+
+  } catch (CoordinatorRegisterInstanceException const &) {
+    return RegisterInstanceCoordinatorStatus::RPC_FAILED;
+  }
+}
+
+}  // namespace memgraph::coordination
+#endif

src/coordination/coordinator_handlers.cpp

@@ -0,0 +1,123 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#ifdef MG_ENTERPRISE
+#include "coordination/coordinator_handlers.hpp"
+
+#include <range/v3/view.hpp>
+
+#include "coordination/coordinator_rpc.hpp"
+#include "coordination/include/coordination/coordinator_server.hpp"
+
+namespace memgraph::dbms {
+
+void CoordinatorHandlers::Register(memgraph::coordination::CoordinatorServer &server,
+                                   replication::ReplicationHandler &replication_handler) {
+  server.Register<coordination::PromoteReplicaToMainRpc>(
+      [&](slk::Reader *req_reader, slk::Builder *res_builder) -> void {
+        spdlog::info("Received PromoteReplicaToMainRpc");
+        CoordinatorHandlers::PromoteReplicaToMainHandler(replication_handler, req_reader, res_builder);
+      });
+
+  server.Register<coordination::DemoteMainToReplicaRpc>(
+      [&replication_handler](slk::Reader *req_reader, slk::Builder *res_builder) -> void {
+        spdlog::info("Received DemoteMainToReplicaRpc from coordinator server");
+        CoordinatorHandlers::DemoteMainToReplicaHandler(replication_handler, req_reader, res_builder);
+      });
+}
+
+void CoordinatorHandlers::DemoteMainToReplicaHandler(replication::ReplicationHandler &replication_handler,
+                                                     slk::Reader *req_reader, slk::Builder *res_builder) {
+  spdlog::info("Executing DemoteMainToReplicaHandler");
+
+  if (!replication_handler.IsMain()) {
+    spdlog::error("Setting to replica must be performed on main.");
+    slk::Save(coordination::DemoteMainToReplicaRes{false}, res_builder);
+    return;
+  }
+
+  coordination::DemoteMainToReplicaReq req;
+  slk::Load(&req, req_reader);
+
+  const replication::ReplicationServerConfig clients_config{
+      .ip_address = req.replication_client_info.replication_ip_address,
+      .port = req.replication_client_info.replication_port};
+
+  if (!replication_handler.SetReplicationRoleReplica(clients_config)) {
+    spdlog::error("Demoting main to replica failed!");
+    slk::Save(coordination::PromoteReplicaToMainRes{false}, res_builder);
+    return;
+  }
+
+  slk::Save(coordination::PromoteReplicaToMainRes{true}, res_builder);
+}
+
+void CoordinatorHandlers::PromoteReplicaToMainHandler(replication::ReplicationHandler &replication_handler,
+                                                      slk::Reader *req_reader, slk::Builder *res_builder) {
+  if (!replication_handler.IsReplica()) {
+    spdlog::error("Failover must be performed on replica!");
+    slk::Save(coordination::PromoteReplicaToMainRes{false}, res_builder);
+    return;
+  }
+
+  // This can fail because of disk. If it does, the cluster state could get inconsistent.
+  // We don't handle disk issues.
+  if (!replication_handler.DoReplicaToMainPromotion()) {
+    spdlog::error("Promoting replica to main failed!");
+    slk::Save(coordination::PromoteReplicaToMainRes{false}, res_builder);
+    return;
+  }
+
+  coordination::PromoteReplicaToMainReq req;
+  slk::Load(&req, req_reader);
+
+  auto const converter = [](const auto &repl_info_config) {
+    return replication::ReplicationClientConfig{
+        .name = repl_info_config.instance_name,
+        .mode = repl_info_config.replication_mode,
+        .ip_address = repl_info_config.replication_ip_address,
+        .port = repl_info_config.replication_port,
+    };
+  };
+
+  // registering replicas
+  for (auto const &config : req.replication_clients_info | ranges::views::transform(converter)) {
+    auto instance_client = replication_handler.RegisterReplica(config);
+    if (instance_client.HasError()) {
+      using enum memgraph::replication::RegisterReplicaError;
+      switch (instance_client.GetError()) {
+        // Can't happen, checked on the coordinator side
+        case memgraph::query::RegisterReplicaError::NAME_EXISTS:
+          spdlog::error("Replica with the same name already exists!");
+          slk::Save(coordination::PromoteReplicaToMainRes{false}, res_builder);
+          return;
+        // Can't happen, checked on the coordinator side
+        case memgraph::query::RegisterReplicaError::ENDPOINT_EXISTS:
+          spdlog::error("Replica with the same endpoint already exists!");
+          slk::Save(coordination::PromoteReplicaToMainRes{false}, res_builder);
+          return;
+        // We don't handle disk issues
+        case memgraph::query::RegisterReplicaError::COULD_NOT_BE_PERSISTED:
+          spdlog::error("Registered replica could not be persisted!");
+          slk::Save(coordination::PromoteReplicaToMainRes{false}, res_builder);
+          return;
+        case memgraph::query::RegisterReplicaError::CONNECTION_FAILED:
+          // Connection failure is not a fatal error
+          break;
+      }
+    }
+  }
+
+  slk::Save(coordination::PromoteReplicaToMainRes{true}, res_builder);
+}
+
+}  // namespace memgraph::dbms
+#endif

src/coordination/coordinator_instance.cpp

@@ -0,0 +1,84 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#ifdef MG_ENTERPRISE
+
+#include "coordination/coordinator_instance.hpp"
+
+namespace memgraph::coordination {
+
+CoordinatorInstance::CoordinatorInstance(CoordinatorData *data, CoordinatorClientConfig config,
+                                         HealthCheckCallback succ_cb, HealthCheckCallback fail_cb)
+    : client_(data, std::move(config), std::move(succ_cb), std::move(fail_cb)),
+      replication_role_(replication_coordination_glue::ReplicationRole::REPLICA),
+      is_alive_(true) {
+  if (!client_.DemoteToReplica()) {
+    throw CoordinatorRegisterInstanceException("Failed to demote instance {} to replica", client_.InstanceName());
+  }
+  client_.StartFrequentCheck();
+}
+
+auto CoordinatorInstance::OnSuccessPing() -> void {
+  last_response_time_ = std::chrono::system_clock::now();
+  is_alive_ = true;
+}
+
+auto CoordinatorInstance::OnFailPing() -> bool {
+  is_alive_ =
+      std::chrono::duration_cast<std::chrono::seconds>(std::chrono::system_clock::now() - last_response_time_).count() <
+      CoordinatorClusterConfig::alive_response_time_difference_sec_;
+  return is_alive_;
+}
+
+auto CoordinatorInstance::InstanceName() const -> std::string { return client_.InstanceName(); }
+auto CoordinatorInstance::SocketAddress() const -> std::string { return client_.SocketAddress(); }
+auto CoordinatorInstance::IsAlive() const -> bool { return is_alive_; }
+
+auto CoordinatorInstance::IsReplica() const -> bool {
+  return replication_role_ == replication_coordination_glue::ReplicationRole::REPLICA;
+}
+auto CoordinatorInstance::IsMain() const -> bool {
+  return replication_role_ == replication_coordination_glue::ReplicationRole::MAIN;
+}
+
+auto CoordinatorInstance::PromoteToMain(ReplicationClientsInfo repl_clients_info, HealthCheckCallback main_succ_cb,
+                                        HealthCheckCallback main_fail_cb) -> bool {
+  if (!client_.SendPromoteReplicaToMainRpc(std::move(repl_clients_info))) {
+    return false;
+  }
+
+  replication_role_ = replication_coordination_glue::ReplicationRole::MAIN;
+  client_.SetCallbacks(std::move(main_succ_cb), std::move(main_fail_cb));
+
+  return true;
+}
+
+auto CoordinatorInstance::DemoteToReplica(HealthCheckCallback replica_succ_cb, HealthCheckCallback replica_fail_cb)
+    -> bool {
+  if (!client_.DemoteToReplica()) {
+    return false;
+  }
+
+  replication_role_ = replication_coordination_glue::ReplicationRole::REPLICA;
+  client_.SetCallbacks(std::move(replica_succ_cb), std::move(replica_fail_cb));
+
+  return true;
+}
+
+auto CoordinatorInstance::PauseFrequentCheck() -> void { client_.PauseFrequentCheck(); }
+auto CoordinatorInstance::ResumeFrequentCheck() -> void { client_.ResumeFrequentCheck(); }
+
+auto CoordinatorInstance::ReplicationClientInfo() const -> CoordinatorClientConfig::ReplicationClientInfo {
+  return client_.ReplicationClientInfo();
+}
+
+}  // namespace memgraph::coordination
+#endif

src/coordination/coordinator_rpc.cpp

@@ -0,0 +1,107 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#ifdef MG_ENTERPRISE
+
+#include "coordination/coordinator_rpc.hpp"
+
+#include "coordination/coordinator_slk.hpp"
+#include "slk/serialization.hpp"
+
+namespace memgraph {
+
+namespace coordination {
+
+void PromoteReplicaToMainReq::Save(const PromoteReplicaToMainReq &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self, builder);
+}
+
+void PromoteReplicaToMainReq::Load(PromoteReplicaToMainReq *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(self, reader);
+}
+
+void PromoteReplicaToMainRes::Save(const PromoteReplicaToMainRes &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self, builder);
+}
+
+void PromoteReplicaToMainRes::Load(PromoteReplicaToMainRes *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(self, reader);
+}
+
+void DemoteMainToReplicaReq::Save(const DemoteMainToReplicaReq &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self, builder);
+}
+
+void DemoteMainToReplicaReq::Load(DemoteMainToReplicaReq *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(self, reader);
+}
+
+void DemoteMainToReplicaRes::Save(const DemoteMainToReplicaRes &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self, builder);
+}
+
+void DemoteMainToReplicaRes::Load(DemoteMainToReplicaRes *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(self, reader);
+}
+
+}  // namespace coordination
+
+constexpr utils::TypeInfo coordination::PromoteReplicaToMainReq::kType{utils::TypeId::COORD_FAILOVER_REQ,
+                                                                       "CoordPromoteReplicaToMainReq", nullptr};
+
+constexpr utils::TypeInfo coordination::PromoteReplicaToMainRes::kType{utils::TypeId::COORD_FAILOVER_RES,
+                                                                       "CoordPromoteReplicaToMainRes", nullptr};
+
+constexpr utils::TypeInfo coordination::DemoteMainToReplicaReq::kType{utils::TypeId::COORD_SET_REPL_MAIN_REQ,
+                                                                      "CoordDemoteToReplicaReq", nullptr};
+
+constexpr utils::TypeInfo coordination::DemoteMainToReplicaRes::kType{utils::TypeId::COORD_SET_REPL_MAIN_RES,
+                                                                      "CoordDemoteToReplicaRes", nullptr};
+
+namespace slk {
+
+void Save(const memgraph::coordination::PromoteReplicaToMainRes &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self.success, builder);
+}
+
+void Load(memgraph::coordination::PromoteReplicaToMainRes *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(&self->success, reader);
+}
+
+void Save(const memgraph::coordination::PromoteReplicaToMainReq &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self.replication_clients_info, builder);
+}
+
+void Load(memgraph::coordination::PromoteReplicaToMainReq *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(&self->replication_clients_info, reader);
+}
+
+void Save(const memgraph::coordination::DemoteMainToReplicaReq &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self.replication_client_info, builder);
+}
+
+void Load(memgraph::coordination::DemoteMainToReplicaReq *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(&self->replication_client_info, reader);
+}
+
+void Save(const memgraph::coordination::DemoteMainToReplicaRes &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self.success, builder);
+}
+
+void Load(memgraph::coordination::DemoteMainToReplicaRes *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(&self->success, reader);
+}
+
+}  // namespace slk
+
+}  // namespace memgraph
+
+#endif

src/coordination/coordinator_server.cpp

@@ -0,0 +1,57 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#ifdef MG_ENTERPRISE
+
+#include "coordination/coordinator_server.hpp"
+#include "replication_coordination_glue/messages.hpp"
+
+namespace memgraph::coordination {
+
+namespace {
+
+auto CreateServerContext(const memgraph::coordination::CoordinatorServerConfig &config)
+    -> communication::ServerContext {
+  return (config.ssl) ? communication::ServerContext{config.ssl->key_file, config.ssl->cert_file, config.ssl->ca_file,
+                                                     config.ssl->verify_peer}
+                      : communication::ServerContext{};
+}
+
+// NOTE: The coordinator server doesn't more than 1 processing thread - each replica can
+// have only a single coordinator server. Also, the single-threaded guarantee
+// simplifies the rest of the implementation.
+constexpr auto kCoordinatorServerThreads = 1;
+
+}  // namespace
+
+CoordinatorServer::CoordinatorServer(const CoordinatorServerConfig &config)
+    : rpc_server_context_{CreateServerContext(config)},
+      rpc_server_{io::network::Endpoint{config.ip_address, config.port}, &rpc_server_context_,
+                  kCoordinatorServerThreads} {
+  rpc_server_.Register<replication_coordination_glue::FrequentHeartbeatRpc>([](auto *req_reader, auto *res_builder) {
+    spdlog::debug("Received FrequentHeartbeatRpc on coordinator server");
+    replication_coordination_glue::FrequentHeartbeatHandler(req_reader, res_builder);
+  });
+}
+
+CoordinatorServer::~CoordinatorServer() {
+  if (rpc_server_.IsRunning()) {
+    auto const &endpoint = rpc_server_.endpoint();
+    spdlog::trace("Closing coordinator server on {}:{}", endpoint.address, endpoint.port);
+    rpc_server_.Shutdown();
+  }
+  rpc_server_.AwaitShutdown();
+}
+
+bool CoordinatorServer::Start() { return rpc_server_.Start(); }
+
+}  // namespace memgraph::coordination
+#endif

src/coordination/coordinator_state.cpp

@@ -0,0 +1,83 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#ifdef MG_ENTERPRISE
+
+#include "coordination/coordinator_state.hpp"
+
+#include "coordination/coordinator_config.hpp"
+#include "coordination/register_main_replica_coordinator_status.hpp"
+#include "flags/replication.hpp"
+#include "spdlog/spdlog.h"
+#include "utils/logging.hpp"
+#include "utils/variant_helpers.hpp"
+
+#include <algorithm>
+
+namespace memgraph::coordination {
+
+CoordinatorState::CoordinatorState() {
+  MG_ASSERT(!(FLAGS_coordinator && FLAGS_coordinator_server_port),
+            "Instance cannot be a coordinator and have registered coordinator server.");
+
+  spdlog::info("Executing coordinator constructor");
+  if (FLAGS_coordinator_server_port) {
+    spdlog::info("Coordinator server port set");
+    auto const config = CoordinatorServerConfig{
+        .ip_address = kDefaultReplicationServerIp,
+        .port = static_cast<uint16_t>(FLAGS_coordinator_server_port),
+    };
+    spdlog::info("Executing coordinator constructor main replica");
+
+    data_ = CoordinatorMainReplicaData{.coordinator_server_ = std::make_unique<CoordinatorServer>(config)};
+  }
+}
+
+auto CoordinatorState::RegisterInstance(CoordinatorClientConfig config) -> RegisterInstanceCoordinatorStatus {
+  MG_ASSERT(std::holds_alternative<CoordinatorData>(data_),
+            "Coordinator cannot register replica since variant holds wrong alternative");
+
+  return std::visit(
+      memgraph::utils::Overloaded{
+          [](const CoordinatorMainReplicaData & /*coordinator_main_replica_data*/) {
+            return RegisterInstanceCoordinatorStatus::NOT_COORDINATOR;
+          },
+          [config](CoordinatorData &coordinator_data) { return coordinator_data.RegisterInstance(config); }},
+      data_);
+}
+
+auto CoordinatorState::SetInstanceToMain(std::string instance_name) -> SetInstanceToMainCoordinatorStatus {
+  MG_ASSERT(std::holds_alternative<CoordinatorData>(data_),
+            "Coordinator cannot register replica since variant holds wrong alternative");
+
+  return std::visit(
+      memgraph::utils::Overloaded{[](const CoordinatorMainReplicaData & /*coordinator_main_replica_data*/) {
+                                    return SetInstanceToMainCoordinatorStatus::NOT_COORDINATOR;
+                                  },
+                                  [&instance_name](CoordinatorData &coordinator_data) {
+                                    return coordinator_data.SetInstanceToMain(instance_name);
+                                  }},
+      data_);
+}
+
+auto CoordinatorState::ShowInstances() const -> std::vector<CoordinatorInstanceStatus> {
+  MG_ASSERT(std::holds_alternative<CoordinatorData>(data_),
+            "Can't call show instances on data_, as variant holds wrong alternative");
+  return std::get<CoordinatorData>(data_).ShowInstances();
+}
+
+auto CoordinatorState::GetCoordinatorServer() const -> CoordinatorServer & {
+  MG_ASSERT(std::holds_alternative<CoordinatorMainReplicaData>(data_),
+            "Cannot get coordinator server since variant holds wrong alternative");
+  return *std::get<CoordinatorMainReplicaData>(data_).coordinator_server_;
+}
+}  // namespace memgraph::coordination
+#endif

src/coordination/include/coordination/constants.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -11,11 +11,12 @@
 
 #pragma once
 
-#include "dbms/dbms_handler.hpp"
-#include "replication/replication_client.hpp"
+namespace memgraph::coordination {
 
-namespace memgraph::dbms {
+#ifdef MG_EXPERIMENTAL_HIGH_AVAILABILITY
+constexpr bool allow_ha = true;
+#else
+constexpr bool allow_ha = false;
+#endif
 
-void StartReplicaClient(DbmsHandler &dbms_handler, replication::ReplicationClient &client);
-
-}  // namespace memgraph::dbms
+}  // namespace memgraph::coordination

src/coordination/include/coordination/coordinator_client.hpp

@@ -0,0 +1,72 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#ifdef MG_ENTERPRISE
+
+#include "coordination/coordinator_config.hpp"
+#include "rpc/client.hpp"
+#include "utils/scheduler.hpp"
+
+namespace memgraph::coordination {
+
+class CoordinatorData;
+using HealthCheckCallback = std::function<void(CoordinatorData *, std::string_view)>;
+using ReplicationClientsInfo = std::vector<ReplClientInfo>;
+
+class CoordinatorClient {
+ public:
+  explicit CoordinatorClient(CoordinatorData *coord_data_, CoordinatorClientConfig config, HealthCheckCallback succ_cb,
+                             HealthCheckCallback fail_cb);
+
+  ~CoordinatorClient() = default;
+
+  CoordinatorClient(CoordinatorClient &) = delete;
+  CoordinatorClient &operator=(CoordinatorClient const &) = delete;
+
+  CoordinatorClient(CoordinatorClient &&) noexcept = delete;
+  CoordinatorClient &operator=(CoordinatorClient &&) noexcept = delete;
+
+  void StartFrequentCheck();
+  void StopFrequentCheck();
+  void PauseFrequentCheck();
+  void ResumeFrequentCheck();
+
+  auto InstanceName() const -> std::string;
+  auto SocketAddress() const -> std::string;
+
+  [[nodiscard]] auto SendPromoteReplicaToMainRpc(ReplicationClientsInfo replication_clients_info) const -> bool;
+  [[nodiscard]] auto DemoteToReplica() const -> bool;
+
+  auto ReplicationClientInfo() const -> ReplClientInfo;
+
+  auto SetCallbacks(HealthCheckCallback succ_cb, HealthCheckCallback fail_cb) -> void;
+
+  friend bool operator==(CoordinatorClient const &first, CoordinatorClient const &second) {
+    return first.config_ == second.config_;
+  }
+
+ private:
+  utils::Scheduler instance_checker_;
+
+  // TODO: (andi) Pimpl?
+  communication::ClientContext rpc_context_;
+  mutable rpc::Client rpc_client_;
+
+  CoordinatorClientConfig config_;
+  CoordinatorData *coord_data_;
+  HealthCheckCallback succ_cb_;
+  HealthCheckCallback fail_cb_;
+};
+
+}  // namespace memgraph::coordination
+#endif

src/coordination/include/coordination/coordinator_cluster_config.hpp

@@ -0,0 +1,22 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#ifdef MG_ENTERPRISE
+namespace memgraph::coordination {
+
+struct CoordinatorClusterConfig {
+  static constexpr int alive_response_time_difference_sec_{5};
+};
+
+}  // namespace memgraph::coordination
+#endif

src/coordination/include/coordination/coordinator_config.hpp

@@ -0,0 +1,77 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#ifdef MG_ENTERPRISE
+
+#include "replication_coordination_glue/mode.hpp"
+
+#include <chrono>
+#include <cstdint>
+#include <optional>
+#include <string>
+
+namespace memgraph::coordination {
+
+inline constexpr auto *kDefaultReplicationServerIp = "0.0.0.0";
+
+struct CoordinatorClientConfig {
+  std::string instance_name;
+  std::string ip_address;
+  uint16_t port{};
+  std::chrono::seconds health_check_frequency_sec{1};
+
+  auto SocketAddress() const -> std::string { return ip_address + ":" + std::to_string(port); }
+
+  struct ReplicationClientInfo {
+    std::string instance_name;
+    replication_coordination_glue::ReplicationMode replication_mode{};
+    std::string replication_ip_address;
+    uint16_t replication_port{};
+
+    friend bool operator==(ReplicationClientInfo const &, ReplicationClientInfo const &) = default;
+  };
+
+  ReplicationClientInfo replication_client_info;
+
+  struct SSL {
+    std::string key_file;
+    std::string cert_file;
+
+    friend bool operator==(const SSL &, const SSL &) = default;
+  };
+
+  std::optional<SSL> ssl;
+
+  friend bool operator==(CoordinatorClientConfig const &, CoordinatorClientConfig const &) = default;
+};
+
+using ReplClientInfo = CoordinatorClientConfig::ReplicationClientInfo;
+
+struct CoordinatorServerConfig {
+  std::string ip_address;
+  uint16_t port{};
+  struct SSL {
+    std::string key_file;
+    std::string cert_file;
+    std::string ca_file;
+    bool verify_peer{};
+    friend bool operator==(SSL const &, SSL const &) = default;
+  };
+
+  std::optional<SSL> ssl;
+
+  friend bool operator==(CoordinatorServerConfig const &, CoordinatorServerConfig const &) = default;
+};
+
+}  // namespace memgraph::coordination
+#endif

src/coordination/include/coordination/coordinator_data.hpp

@@ -0,0 +1,52 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#ifdef MG_ENTERPRISE
+
+#include "coordination/coordinator_instance.hpp"
+#include "coordination/coordinator_instance_status.hpp"
+#include "coordination/coordinator_server.hpp"
+#include "coordination/register_main_replica_coordinator_status.hpp"
+#include "utils/rw_lock.hpp"
+#include "utils/thread_pool.hpp"
+
+#include <list>
+
+namespace memgraph::coordination {
+class CoordinatorData {
+ public:
+  CoordinatorData();
+
+  [[nodiscard]] auto RegisterInstance(CoordinatorClientConfig config) -> RegisterInstanceCoordinatorStatus;
+
+  [[nodiscard]] auto SetInstanceToMain(std::string instance_name) -> SetInstanceToMainCoordinatorStatus;
+
+  auto TryFailover() -> void;
+
+  auto ShowInstances() const -> std::vector<CoordinatorInstanceStatus>;
+
+ private:
+  auto ClusterHasAliveMain_() const -> bool;
+
+  mutable utils::RWLock coord_data_lock_{utils::RWLock::Priority::READ};
+  HealthCheckCallback main_succ_cb_, main_fail_cb_, replica_succ_cb_, replica_fail_cb_;
+  // NOTE: Must be std::list because we rely on pointer stability
+  std::list<CoordinatorInstance> registered_instances_;
+};
+
+struct CoordinatorMainReplicaData {
+  std::unique_ptr<CoordinatorServer> coordinator_server_;
+};
+
+}  // namespace memgraph::coordination
+#endif

src/coordination/include/coordination/coordinator_exceptions.hpp

@@ -0,0 +1,32 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#ifdef MG_ENTERPRISE
+
+#include "utils/exceptions.hpp"
+
+namespace memgraph::coordination {
+class CoordinatorRegisterInstanceException final : public utils::BasicException {
+ public:
+  explicit CoordinatorRegisterInstanceException(const std::string_view what) noexcept
+      : BasicException("Failed to create instance: " + std::string(what)) {}
+
+  template <class... Args>
+  explicit CoordinatorRegisterInstanceException(fmt::format_string<Args...> fmt, Args &&...args) noexcept
+      : CoordinatorRegisterInstanceException(fmt::format(fmt, std::forward<Args>(args)...)) {}
+
+  SPECIALIZE_GET_EXCEPTION_NAME(CoordinatorRegisterInstanceException)
+};
+
+}  // namespace memgraph::coordination
+#endif

src/coordination/include/coordination/coordinator_handlers.hpp

@@ -0,0 +1,38 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#ifdef MG_ENTERPRISE
+
+#include "coordination/coordinator_server.hpp"
+#include "replication_handler/replication_handler.hpp"
+#include "slk/streams.hpp"
+
+namespace memgraph::dbms {
+
+class DbmsHandler;
+
+class CoordinatorHandlers {
+ public:
+  static void Register(memgraph::coordination::CoordinatorServer &server,
+                       replication::ReplicationHandler &replication_handler);
+
+ private:
+  static void PromoteReplicaToMainHandler(replication::ReplicationHandler &replication_handler, slk::Reader *req_reader,
+                                          slk::Builder *res_builder);
+  static void DemoteMainToReplicaHandler(replication::ReplicationHandler &replication_handler, slk::Reader *req_reader,
+                                         slk::Builder *res_builder);
+};
+
+}  // namespace memgraph::dbms
+
+#endif

src/coordination/include/coordination/coordinator_instance.hpp

@@ -0,0 +1,68 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#ifdef MG_ENTERPRISE
+
+#include "coordination/coordinator_client.hpp"
+#include "coordination/coordinator_cluster_config.hpp"
+#include "coordination/coordinator_exceptions.hpp"
+#include "replication_coordination_glue/role.hpp"
+
+namespace memgraph::coordination {
+
+class CoordinatorData;
+
+class CoordinatorInstance {
+ public:
+  CoordinatorInstance(CoordinatorData *data, CoordinatorClientConfig config, HealthCheckCallback succ_cb,
+                      HealthCheckCallback fail_cb);
+
+  CoordinatorInstance(CoordinatorInstance const &other) = delete;
+  CoordinatorInstance &operator=(CoordinatorInstance const &other) = delete;
+  CoordinatorInstance(CoordinatorInstance &&other) noexcept = delete;
+  CoordinatorInstance &operator=(CoordinatorInstance &&other) noexcept = delete;
+  ~CoordinatorInstance() = default;
+
+  auto OnSuccessPing() -> void;
+  auto OnFailPing() -> bool;
+
+  auto IsAlive() const -> bool;
+
+  auto InstanceName() const -> std::string;
+  auto SocketAddress() const -> std::string;
+
+  auto IsReplica() const -> bool;
+  auto IsMain() const -> bool;
+
+  auto PromoteToMain(ReplicationClientsInfo repl_clients_info, HealthCheckCallback main_succ_cb,
+                     HealthCheckCallback main_fail_cb) -> bool;
+  auto DemoteToReplica(HealthCheckCallback replica_succ_cb, HealthCheckCallback replica_fail_cb) -> bool;
+
+  auto PauseFrequentCheck() -> void;
+  auto ResumeFrequentCheck() -> void;
+
+  auto ReplicationClientInfo() const -> ReplClientInfo;
+
+ private:
+  CoordinatorClient client_;
+  replication_coordination_glue::ReplicationRole replication_role_;
+  std::chrono::system_clock::time_point last_response_time_{};
+  bool is_alive_{false};
+
+  friend bool operator==(CoordinatorInstance const &first, CoordinatorInstance const &second) {
+    return first.client_ == second.client_ && first.replication_role_ == second.replication_role_;
+  }
+};
+
+}  // namespace memgraph::coordination
+#endif

src/coordination/include/coordination/coordinator_instance_status.hpp

@@ -0,0 +1,31 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#ifdef MG_ENTERPRISE
+
+#include "io/network/endpoint.hpp"
+
+#include <string_view>
+
+namespace memgraph::coordination {
+
+struct CoordinatorInstanceStatus {
+  std::string instance_name;
+  std::string socket_address;
+  std::string replication_role;
+  bool is_alive;
+};
+
+}  // namespace memgraph::coordination
+
+#endif

src/coordination/include/coordination/coordinator_rpc.hpp

@@ -0,0 +1,104 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#ifdef MG_ENTERPRISE
+
+#include "coordination/coordinator_config.hpp"
+#include "rpc/messages.hpp"
+#include "slk/serialization.hpp"
+
+namespace memgraph::coordination {
+
+struct PromoteReplicaToMainReq {
+  static const utils::TypeInfo kType;
+  static const utils::TypeInfo &GetTypeInfo() { return kType; }
+
+  static void Load(PromoteReplicaToMainReq *self, memgraph::slk::Reader *reader);
+  static void Save(const PromoteReplicaToMainReq &self, memgraph::slk::Builder *builder);
+
+  explicit PromoteReplicaToMainReq(std::vector<CoordinatorClientConfig::ReplicationClientInfo> replication_clients_info)
+      : replication_clients_info(std::move(replication_clients_info)) {}
+  PromoteReplicaToMainReq() = default;
+
+  std::vector<CoordinatorClientConfig::ReplicationClientInfo> replication_clients_info;
+};
+
+struct PromoteReplicaToMainRes {
+  static const utils::TypeInfo kType;
+  static const utils::TypeInfo &GetTypeInfo() { return kType; }
+
+  static void Load(PromoteReplicaToMainRes *self, memgraph::slk::Reader *reader);
+  static void Save(const PromoteReplicaToMainRes &self, memgraph::slk::Builder *builder);
+
+  explicit PromoteReplicaToMainRes(bool success) : success(success) {}
+  PromoteReplicaToMainRes() = default;
+
+  bool success;
+};
+
+using PromoteReplicaToMainRpc = rpc::RequestResponse<PromoteReplicaToMainReq, PromoteReplicaToMainRes>;
+
+struct DemoteMainToReplicaReq {
+  static const utils::TypeInfo kType;
+  static const utils::TypeInfo &GetTypeInfo() { return kType; }
+
+  static void Load(DemoteMainToReplicaReq *self, memgraph::slk::Reader *reader);
+  static void Save(const DemoteMainToReplicaReq &self, memgraph::slk::Builder *builder);
+
+  explicit DemoteMainToReplicaReq(CoordinatorClientConfig::ReplicationClientInfo replication_client_info)
+      : replication_client_info(std::move(replication_client_info)) {}
+
+  DemoteMainToReplicaReq() = default;
+
+  CoordinatorClientConfig::ReplicationClientInfo replication_client_info;
+};
+
+struct DemoteMainToReplicaRes {
+  static const utils::TypeInfo kType;
+  static const utils::TypeInfo &GetTypeInfo() { return kType; }
+
+  static void Load(DemoteMainToReplicaRes *self, memgraph::slk::Reader *reader);
+  static void Save(const DemoteMainToReplicaRes &self, memgraph::slk::Builder *builder);
+
+  explicit DemoteMainToReplicaRes(bool success) : success(success) {}
+  DemoteMainToReplicaRes() = default;
+
+  bool success;
+};
+
+using DemoteMainToReplicaRpc = rpc::RequestResponse<DemoteMainToReplicaReq, DemoteMainToReplicaRes>;
+
+}  // namespace memgraph::coordination
+
+// SLK serialization declarations
+namespace memgraph::slk {
+
+void Save(const memgraph::coordination::PromoteReplicaToMainRes &self, memgraph::slk::Builder *builder);
+
+void Load(memgraph::coordination::PromoteReplicaToMainRes *self, memgraph::slk::Reader *reader);
+
+void Save(const memgraph::coordination::PromoteReplicaToMainReq &self, memgraph::slk::Builder *builder);
+
+void Load(memgraph::coordination::PromoteReplicaToMainReq *self, memgraph::slk::Reader *reader);
+
+void Save(const memgraph::coordination::DemoteMainToReplicaRes &self, memgraph::slk::Builder *builder);
+
+void Load(memgraph::coordination::DemoteMainToReplicaRes *self, memgraph::slk::Reader *reader);
+
+void Save(const memgraph::coordination::DemoteMainToReplicaReq &self, memgraph::slk::Builder *builder);
+
+void Load(memgraph::coordination::DemoteMainToReplicaReq *self, memgraph::slk::Reader *reader);
+
+}  // namespace memgraph::slk
+
+#endif

src/coordination/include/coordination/coordinator_server.hpp

@@ -0,0 +1,44 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#ifdef MG_ENTERPRISE
+
+#include "coordination/coordinator_config.hpp"
+#include "rpc/server.hpp"
+
+namespace memgraph::coordination {
+
+class CoordinatorServer {
+ public:
+  explicit CoordinatorServer(const CoordinatorServerConfig &config);
+  CoordinatorServer(const CoordinatorServer &) = delete;
+  CoordinatorServer(CoordinatorServer &&) = delete;
+  CoordinatorServer &operator=(const CoordinatorServer &) = delete;
+  CoordinatorServer &operator=(CoordinatorServer &&) = delete;
+
+  virtual ~CoordinatorServer();
+
+  bool Start();
+
+  template <typename TRequestResponse, typename F>
+  void Register(F &&callback) {
+    rpc_server_.Register<TRequestResponse>(std::forward<F>(callback));
+  }
+
+ private:
+  communication::ServerContext rpc_server_context_;
+  rpc::Server rpc_server_;
+};
+
+}  // namespace memgraph::coordination
+#endif

src/coordination/include/coordination/coordinator_slk.hpp

@@ -0,0 +1,38 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#ifdef MG_ENTERPRISE
+
+#include "coordination/coordinator_config.hpp"
+#include "slk/serialization.hpp"
+#include "slk/streams.hpp"
+
+namespace memgraph::slk {
+
+using ReplicationClientInfo = coordination::CoordinatorClientConfig::ReplicationClientInfo;
+
+inline void Save(const ReplicationClientInfo &obj, Builder *builder) {
+  Save(obj.instance_name, builder);
+  Save(obj.replication_mode, builder);
+  Save(obj.replication_ip_address, builder);
+  Save(obj.replication_port, builder);
+}
+
+inline void Load(ReplicationClientInfo *obj, Reader *reader) {
+  Load(&obj->instance_name, reader);
+  Load(&obj->replication_mode, reader);
+  Load(&obj->replication_ip_address, reader);
+  Load(&obj->replication_port, reader);
+}
+}  // namespace memgraph::slk
+#endif

src/coordination/include/coordination/coordinator_state.hpp

@@ -0,0 +1,50 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#ifdef MG_ENTERPRISE
+
+#include "coordination/coordinator_data.hpp"
+#include "coordination/coordinator_instance_status.hpp"
+#include "coordination/coordinator_server.hpp"
+#include "coordination/register_main_replica_coordinator_status.hpp"
+
+#include <variant>
+
+namespace memgraph::coordination {
+
+class CoordinatorState {
+ public:
+  CoordinatorState();
+  ~CoordinatorState() = default;
+
+  CoordinatorState(CoordinatorState const &) = delete;
+  CoordinatorState &operator=(CoordinatorState const &) = delete;
+
+  CoordinatorState(CoordinatorState &&) noexcept = delete;
+  CoordinatorState &operator=(CoordinatorState &&) noexcept = delete;
+
+  [[nodiscard]] auto RegisterInstance(CoordinatorClientConfig config) -> RegisterInstanceCoordinatorStatus;
+
+  [[nodiscard]] auto SetInstanceToMain(std::string instance_name) -> SetInstanceToMainCoordinatorStatus;
+
+  auto ShowInstances() const -> std::vector<CoordinatorInstanceStatus>;
+
+  // The client code must check that the server exists before calling this method.
+  auto GetCoordinatorServer() const -> CoordinatorServer &;
+
+ private:
+  std::variant<CoordinatorData, CoordinatorMainReplicaData> data_;
+};
+
+}  // namespace memgraph::coordination
+#endif

src/coordination/include/coordination/register_main_replica_coordinator_status.hpp

@@ -0,0 +1,36 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#ifdef MG_ENTERPRISE
+
+#include <cstdint>
+
+namespace memgraph::coordination {
+
+enum class RegisterInstanceCoordinatorStatus : uint8_t {
+  NAME_EXISTS,
+  ENDPOINT_EXISTS,
+  NOT_COORDINATOR,
+  RPC_FAILED,
+  SUCCESS
+};
+
+enum class SetInstanceToMainCoordinatorStatus : uint8_t {
+  NO_INSTANCE_WITH_NAME,
+  NOT_COORDINATOR,
+  SUCCESS,
+  COULD_NOT_PROMOTE_TO_MAIN,
+};
+
+}  // namespace memgraph::coordination
+#endif

src/dbms/CMakeLists.txt

@@ -1,3 +1,10 @@
+add_library(mg-dbms STATIC
+        dbms_handler.cpp
+        database.cpp
+        coordinator_handler.cpp
+        inmemory/replication_handlers.cpp
+        replication_handlers.cpp
+        rpc.cpp
 
-add_library(mg-dbms STATIC dbms_handler.cpp database.cpp replication_handler.cpp replication_client.cpp inmemory/replication_handlers.cpp)
-target_link_libraries(mg-dbms mg-utils mg-storage-v2 mg-query)
+)
+target_link_libraries(mg-dbms mg-utils mg-storage-v2 mg-query mg-auth mg-replication mg-coordination)

src/dbms/coordinator_handler.cpp

@@ -0,0 +1,39 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#include "coordination/register_main_replica_coordinator_status.hpp"
+#ifdef MG_ENTERPRISE
+
+#include "dbms/coordinator_handler.hpp"
+
+#include "dbms/dbms_handler.hpp"
+
+namespace memgraph::dbms {
+
+CoordinatorHandler::CoordinatorHandler(coordination::CoordinatorState &coordinator_state)
+    : coordinator_state_(coordinator_state) {}
+
+auto CoordinatorHandler::RegisterInstance(memgraph::coordination::CoordinatorClientConfig config)
+    -> coordination::RegisterInstanceCoordinatorStatus {
+  return coordinator_state_.RegisterInstance(config);
+}
+
+auto CoordinatorHandler::SetInstanceToMain(std::string instance_name)
+    -> coordination::SetInstanceToMainCoordinatorStatus {
+  return coordinator_state_.SetInstanceToMain(std::move(instance_name));
+}
+
+auto CoordinatorHandler::ShowInstances() const -> std::vector<coordination::CoordinatorInstanceStatus> {
+  return coordinator_state_.ShowInstances();
+}
+}  // namespace memgraph::dbms
+
+#endif

src/dbms/coordinator_handler.hpp

@@ -0,0 +1,43 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#ifdef MG_ENTERPRISE
+
+#include "coordination/coordinator_config.hpp"
+#include "coordination/coordinator_instance_status.hpp"
+#include "coordination/coordinator_state.hpp"
+#include "coordination/register_main_replica_coordinator_status.hpp"
+
+#include <vector>
+
+namespace memgraph::dbms {
+
+class DbmsHandler;
+
+class CoordinatorHandler {
+ public:
+  explicit CoordinatorHandler(coordination::CoordinatorState &coordinator_state);
+
+  auto RegisterInstance(coordination::CoordinatorClientConfig config)
+      -> coordination::RegisterInstanceCoordinatorStatus;
+
+  auto SetInstanceToMain(std::string instance_name) -> coordination::SetInstanceToMainCoordinatorStatus;
+
+  auto ShowInstances() const -> std::vector<coordination::CoordinatorInstanceStatus>;
+
+ private:
+  coordination::CoordinatorState &coordinator_state_;
+};
+
+}  // namespace memgraph::dbms
+#endif

src/dbms/database.cpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -11,10 +11,7 @@
 
 #include "dbms/database.hpp"
 #include "dbms/inmemory/storage_helper.hpp"
-#include "dbms/replication_handler.hpp"
-#include "flags/storage_mode.hpp"
 #include "storage/v2/disk/storage.hpp"
-#include "storage/v2/inmemory/storage.hpp"
 #include "storage/v2/storage_mode.hpp"
 
 template struct memgraph::utils::Gatekeeper<memgraph::dbms::Database>;

src/dbms/database.hpp

@@ -110,7 +110,7 @@ class Database {
    * @param force_directory Use the configured directory, do not try to decipher the multi-db version
    * @return DatabaseInfo
    */
-  DatabaseInfo GetInfo(bool force_directory, replication::ReplicationRole replication_role) const {
+  DatabaseInfo GetInfo(bool force_directory, replication_coordination_glue::ReplicationRole replication_role) const {
     DatabaseInfo info;
     info.storage_info = storage_->GetInfo(force_directory, replication_role);
     info.triggers = trigger_store_.GetTriggerInfo().size();

src/dbms/dbms_handler.cpp

@@ -16,21 +16,68 @@
 
 #include "dbms/constants.hpp"
 #include "dbms/global.hpp"
-#include "dbms/replication_client.hpp"
 #include "spdlog/spdlog.h"
+#include "system/include/system/system.hpp"
 #include "utils/exceptions.hpp"
 #include "utils/logging.hpp"
 #include "utils/uuid.hpp"
 
 namespace memgraph::dbms {
 
-#ifdef MG_ENTERPRISE
-
 namespace {
-constexpr std::string_view kDBPrefix = "database:";                               // Key prefix for database durability
-constexpr std::string_view kLastCommitedSystemTsKey = "last_commited_system_ts";  // Key for timestamp durability
+constexpr std::string_view kDBPrefix = "database:";  // Key prefix for database durability
+
+std::string RegisterReplicaErrorToString(query::RegisterReplicaError error) {
+  switch (error) {
+    using enum query::RegisterReplicaError;
+    case NAME_EXISTS:
+      return "NAME_EXISTS";
+    case ENDPOINT_EXISTS:
+      return "ENDPOINT_EXISTS";
+    case CONNECTION_FAILED:
+      return "CONNECTION_FAILED";
+    case COULD_NOT_BE_PERSISTED:
+      return "COULD_NOT_BE_PERSISTED";
+  }
+}
+
+// Per storage
+// NOTE Storage will connect to all replicas. Future work might change this
+void RestoreReplication(replication::RoleMainData &mainData, DatabaseAccess db_acc) {
+  spdlog::info("Restoring replication role.");
+
+  // Each individual client has already been restored and started. Here we just go through each database and start its
+  // client
+  for (auto &instance_client : mainData.registered_replicas_) {
+    spdlog::info("Replica {} restoration started for {}.", instance_client.name_, db_acc->name());
+    const auto &ret = db_acc->storage()->repl_storage_state_.replication_clients_.WithLock(
+        [&, db_acc](auto &storage_clients) mutable -> utils::BasicResult<query::RegisterReplicaError> {
+          auto client = std::make_unique<storage::ReplicationStorageClient>(instance_client);
+          auto *storage = db_acc->storage();
+          client->Start(storage, std::move(db_acc));
+          // After start the storage <-> replica state should be READY or RECOVERING (if correctly started)
+          // MAYBE_BEHIND isn't a statement of the current state, this is the default value
+          // Failed to start due to branching of MAIN and REPLICA
+          if (client->State() == storage::replication::ReplicaState::MAYBE_BEHIND) {
+            spdlog::warn("Connection failed when registering replica {}. Replica will still be registered.",
+                         instance_client.name_);
+          }
+          storage_clients.push_back(std::move(client));
+          return {};
+        });
+
+    if (ret.HasError()) {
+      MG_ASSERT(query::RegisterReplicaError::CONNECTION_FAILED != ret.GetError());
+      LOG_FATAL("Failure when restoring replica {}: {}.", instance_client.name_,
+                RegisterReplicaErrorToString(ret.GetError()));
+    }
+    spdlog::info("Replica {} restored for {}.", instance_client.name_, db_acc->name());
+  }
+  spdlog::info("Replication role restored to MAIN.");
+}
 }  // namespace
 
+#ifdef MG_ENTERPRISE
 struct Durability {
   enum class DurabilityVersion : uint8_t {
     V0 = 0,
@@ -109,11 +156,9 @@ struct Durability {
   }
 };
 
-DbmsHandler::DbmsHandler(
-    storage::Config config,
-    memgraph::utils::Synchronized<memgraph::auth::Auth, memgraph::utils::WritePrioritizedRWLock> *auth,
-    bool recovery_on_startup)
-    : default_config_{std::move(config)}, repl_state_{ReplicationStateRootPath(default_config_)} {
+DbmsHandler::DbmsHandler(storage::Config config, memgraph::system::System &system,
+                         replication::ReplicationState &repl_state, auth::SynchedAuth &auth, bool recovery_on_startup)
+    : default_config_{std::move(config)}, auth_{auth}, repl_state_{repl_state}, system_{&system} {
   // TODO: Decouple storage config from dbms config
   // TODO: Save individual db configs inside the kvstore and restore from there
 
@@ -147,19 +192,13 @@ DbmsHandler::DbmsHandler(
       const auto uuid = json.at("uuid").get<utils::UUID>();
       const auto rel_dir = json.at("rel_dir").get<std::filesystem::path>();
       spdlog::info("Restoring database {} at {}.", name, rel_dir);
-      auto new_db = New_(name, uuid, rel_dir);
+      auto new_db = New_(name, uuid, nullptr, rel_dir);
       MG_ASSERT(!new_db.HasError(), "Failed while creating database {}.", name);
       directories.emplace(rel_dir.filename());
       spdlog::info("Database {} restored.", name);
     }
-    // Read the last timestamp
-    auto lcst = durability_->Get(kLastCommitedSystemTsKey);
-    if (lcst) {
-      last_commited_system_timestamp_ = std::stoul(*lcst);
-      system_timestamp_ = last_commited_system_timestamp_;
-    }
   } else {  // Clear databases from the durability list and auth
-    auto locked_auth = auth->Lock();
+    auto locked_auth = auth_.Lock();
     auto it = durability_->begin(std::string{kDBPrefix});
     auto end = durability_->end(std::string{kDBPrefix});
     for (; it != end; ++it) {
@@ -169,8 +208,6 @@ DbmsHandler::DbmsHandler(
       locked_auth->DeleteDatabase(name);
       durability_->Delete(key);
     }
-    // Delete the last timestamp
-    durability_->Delete(kLastCommitedSystemTsKey);
   }
 
   /*
@@ -195,39 +232,29 @@ DbmsHandler::DbmsHandler(
    */
   // Setup the default DB
   SetupDefault_();
-
-  /*
-   * REPLICATION RECOVERY AND STARTUP
-   */
-  // Startup replication state (if recovered at startup)
-  auto replica = [this](replication::RoleReplicaData const &data) { return StartRpcServer(*this, data); };
-  // Replication recovery and frequent check start
-  auto main = [this](replication::RoleMainData &data) {
-    for (auto &client : data.registered_replicas_) {
-      SystemRestore(client);
-    }
-    ForEach([this](DatabaseAccess db) { RecoverReplication(db); });
-    for (auto &client : data.registered_replicas_) {
-      StartReplicaClient(*this, client);
-    }
-    return true;
-  };
-  // Startup proccess for main/replica
-  MG_ASSERT(std::visit(memgraph::utils::Overloaded{replica, main}, repl_state_.ReplicationData()),
-            "Replica recovery failure!");
-
-  // Warning
-  if (default_config_.durability.snapshot_wal_mode == storage::Config::Durability::SnapshotWalMode::DISABLED &&
-      repl_state_.IsMain()) {
-    spdlog::warn(
-        "The instance has the MAIN replication role, but durability logs and snapshots are disabled. Please "
-        "consider "
-        "enabling durability by using --storage-snapshot-interval-sec and --storage-wal-enabled flags because "
-        "without write-ahead logs this instance is not replicating any data.");
-  }
 }
 
-DbmsHandler::DeleteResult DbmsHandler::TryDelete(std::string_view db_name) {
+struct DropDatabase : memgraph::system::ISystemAction {
+  explicit DropDatabase(utils::UUID uuid) : uuid_{uuid} {}
+  void DoDurability() override { /* Done during DBMS execution */
+  }
+
+  bool DoReplication(replication::ReplicationClient &client, replication::ReplicationEpoch const &epoch,
+                     memgraph::system::Transaction const &txn) const override {
+    auto check_response = [](const storage::replication::DropDatabaseRes &response) {
+      return response.result != storage::replication::DropDatabaseRes::Result::FAILURE;
+    };
+
+    return client.SteamAndFinalizeDelta<storage::replication::DropDatabaseRpc>(
+        check_response, epoch.id(), txn.last_committed_system_timestamp(), txn.timestamp(), uuid_);
+  }
+  void PostReplication(replication::RoleMainData &mainData) const override {}
+
+ private:
+  utils::UUID uuid_;
+};
+
+DbmsHandler::DeleteResult DbmsHandler::TryDelete(std::string_view db_name, system::Transaction *transaction) {
   std::lock_guard<LockT> wr(lock_);
   if (db_name == kDefaultDB) {
     // MSG cannot delete the default db
@@ -264,9 +291,10 @@ DbmsHandler::DeleteResult DbmsHandler::TryDelete(std::string_view db_name) {
 
   // Success
   // Save delta
-  if (system_transaction_) {
-    system_transaction_->delta.emplace(SystemTransaction::Delta::drop_database, uuid);
+  if (transaction) {
+    transaction->AddAction<DropDatabase>(uuid);
   }
+
   return {};
 }
 
@@ -287,18 +315,48 @@ DbmsHandler::DeleteResult DbmsHandler::Delete(utils::UUID uuid) {
   return Delete_(db_name);
 }
 
-DbmsHandler::NewResultT DbmsHandler::New_(storage::Config storage_config) {
+struct CreateDatabase : memgraph::system::ISystemAction {
+  explicit CreateDatabase(storage::SalientConfig config, DatabaseAccess db_acc)
+      : config_{std::move(config)}, db_acc(db_acc) {}
+
+  void DoDurability() override {
+    // Done during dbms execution
+  }
+
+  bool DoReplication(replication::ReplicationClient &client, replication::ReplicationEpoch const &epoch,
+                     memgraph::system::Transaction const &txn) const override {
+    auto check_response = [](const storage::replication::CreateDatabaseRes &response) {
+      return response.result != storage::replication::CreateDatabaseRes::Result::FAILURE;
+    };
+
+    return client.SteamAndFinalizeDelta<storage::replication::CreateDatabaseRpc>(
+        check_response, epoch.id(), txn.last_committed_system_timestamp(), txn.timestamp(), config_);
+  }
+
+  void PostReplication(replication::RoleMainData &mainData) const override {
+    // Sync database with REPLICAs
+    // NOTE: The function bellow is used to create ReplicationStorageClient, so it must be called on a new storage
+    // We don't need to have it here, since the function won't fail even if the replication client fails to
+    // connect We will just have everything ready, for recovery at some point.
+    dbms::DbmsHandler::RecoverStorageReplication(db_acc, mainData);
+  }
+
+ private:
+  storage::SalientConfig config_;
+  DatabaseAccess db_acc;
+};
+
+DbmsHandler::NewResultT DbmsHandler::New_(storage::Config storage_config, system::Transaction *txn) {
   auto new_db = db_handler_.New(storage_config, repl_state_);
 
   if (new_db.HasValue()) {  // Success
                             // Save delta
-    if (system_transaction_) {
-      system_transaction_->delta.emplace(SystemTransaction::Delta::create_database, storage_config.salient);
-    }
     UpdateDurability(storage_config);
-    return new_db.GetValue();
+    if (txn) {
+      txn->AddAction<CreateDatabase>(storage_config.salient, new_db.GetValue());
+    }
   }
-  return new_db.GetError();
+  return new_db;
 }
 
 DbmsHandler::DeleteResult DbmsHandler::Delete_(std::string_view db_name) {
@@ -352,94 +410,16 @@ void DbmsHandler::UpdateDurability(const storage::Config &config, std::optional<
   durability_->Put(key, val);
 }
 
-AllSyncReplicaStatus DbmsHandler::Commit() {
-  if (system_transaction_ == std::nullopt || system_transaction_->delta == std::nullopt)
-    return AllSyncReplicaStatus::AllCommitsConfirmed;  // Nothing to commit
-  const auto &delta = *system_transaction_->delta;
-
-  auto sync_status = AllSyncReplicaStatus::AllCommitsConfirmed;
-  // TODO Create a system client that can handle all of this automatically
-  switch (delta.action) {  // TODO for
-    using enum SystemTransaction::Delta::Action;
-    case CREATE_DATABASE: {
-      // Replication
-      auto main_handler = [&](memgraph::replication::RoleMainData &main_data) {
-        // TODO: data race issue? registered_replicas_ access not protected
-        // This is sync in any case, as this is the startup
-        for (auto &client : main_data.registered_replicas_) {
-          bool completed = SteamAndFinalizeDelta<storage::replication::CreateDatabaseRpc>(
-              client,
-              [](const storage::replication::CreateDatabaseRes &response) {
-                return response.result != storage::replication::CreateDatabaseRes::Result::FAILURE;
-              },
-              std::string(main_data.epoch_.id()), last_commited_system_timestamp_,
-              system_transaction_->system_timestamp, delta.config);
-          // TODO: reduce duplicate code
-          if (!completed && client.mode_ == replication::ReplicationMode::SYNC) {
-            sync_status = AllSyncReplicaStatus::SomeCommitsUnconfirmed;
-          }
-        }
-        // Sync database with REPLICAs
-        RecoverReplication(Get_(delta.config.name));
-      };
-      auto replica_handler = [](memgraph::replication::RoleReplicaData &) { /* Nothing to do */ };
-      std::visit(utils::Overloaded{main_handler, replica_handler}, repl_state_.ReplicationData());
-    } break;
-    case DROP_DATABASE: {
-      // Replication
-      auto main_handler = [&](memgraph::replication::RoleMainData &main_data) {
-        // TODO: data race issue? registered_replicas_ access not protected
-        // This is sync in any case, as this is the startup
-        for (auto &client : main_data.registered_replicas_) {
-          bool completed = SteamAndFinalizeDelta<storage::replication::DropDatabaseRpc>(
-              client,
-              [](const storage::replication::DropDatabaseRes &response) {
-                return response.result != storage::replication::DropDatabaseRes::Result::FAILURE;
-              },
-              std::string(main_data.epoch_.id()), last_commited_system_timestamp_,
-              system_transaction_->system_timestamp, delta.uuid);
-          // TODO: reduce duplicate code
-          if (!completed && client.mode_ == replication::ReplicationMode::SYNC) {
-            sync_status = AllSyncReplicaStatus::SomeCommitsUnconfirmed;
-          }
-        }
-      };
-      auto replica_handler = [](memgraph::replication::RoleReplicaData &) { /* Nothing to do */ };
-      std::visit(utils::Overloaded{main_handler, replica_handler}, repl_state_.ReplicationData());
-    } break;
-    case UPDATE_AUTH_DATA:  // TODO
-    case DROP_AUTH_DATA:    // TODO
-      break;
-  }
-
-  durability_->Put(kLastCommitedSystemTsKey, std::to_string(system_transaction_->system_timestamp));
-  last_commited_system_timestamp_ = system_transaction_->system_timestamp;
-  ResetSystemTransaction();
-  return sync_status;
-}
-
-#else  // not MG_ENTERPRISE
-
-AllSyncReplicaStatus DbmsHandler::Commit() {
-  if (system_transaction_ == std::nullopt || system_transaction_->delta == std::nullopt) {
-    return AllSyncReplicaStatus::AllCommitsConfirmed;  // Nothing to commit
-  }
-  const auto &delta = *system_transaction_->delta;
-
-  switch (delta.action) {
-    using enum SystemTransaction::Delta::Action;
-    case CREATE_DATABASE:
-    case DROP_DATABASE:
-    case UPDATE_AUTH_DATA:  // TODO Do we want to have auth replication under community?
-    case DROP_AUTH_DATA:    // TODO Do we want to have auth replication under community?
-      /* Community edition doesn't support multi-tenant replication */
-      break;
-  }
-
-  last_commited_system_timestamp_ = system_transaction_->system_timestamp;
-  ResetSystemTransaction();
-  return AllSyncReplicaStatus::AllCommitsConfirmed;
-}
-
 #endif
+
+void DbmsHandler::RecoverStorageReplication(DatabaseAccess db_acc, replication::RoleMainData &role_main_data) {
+  if (allow_mt_repl || db_acc->name() == dbms::kDefaultDB) {
+    // Handle global replication state
+    spdlog::info("Replication configuration will be stored and will be automatically restored in case of a crash.");
+    // RECOVER REPLICA CONNECTIONS
+    memgraph::dbms::RestoreReplication(role_main_data, db_acc);
+  } else if (!role_main_data.registered_replicas_.empty()) {
+    spdlog::warn("Multi-tenant replication is currently not supported!");
+  }
+}
 }  // namespace memgraph::dbms

src/dbms/dbms_handler.hpp

@@ -25,23 +25,24 @@
 #include "constants.hpp"
 #include "dbms/database.hpp"
 #include "dbms/inmemory/replication_handlers.hpp"
-#include "dbms/replication_handler.hpp"
+#include "dbms/rpc.hpp"
 #include "kvstore/kvstore.hpp"
+#include "license/license.hpp"
 #include "replication/replication_client.hpp"
 #include "storage/v2/config.hpp"
-#include "storage/v2/replication/enums.hpp"
-#include "storage/v2/replication/rpc.hpp"
 #include "storage/v2/transaction.hpp"
+#include "system/system.hpp"
 #include "utils/thread_pool.hpp"
 #ifdef MG_ENTERPRISE
+#include "coordination/coordinator_state.hpp"
 #include "dbms/database_handler.hpp"
 #endif
-#include "dbms/transaction.hpp"
 #include "global.hpp"
 #include "query/config.hpp"
 #include "query/interpreter_context.hpp"
 #include "spdlog/spdlog.h"
 #include "storage/v2/isolation_level.hpp"
+#include "system/system.hpp"
 #include "utils/logging.hpp"
 #include "utils/result.hpp"
 #include "utils/rw_lock.hpp"
@@ -50,11 +51,6 @@
 
 namespace memgraph::dbms {
 
-enum class AllSyncReplicaStatus {
-  AllCommitsConfirmed,
-  SomeCommitsUnconfirmed,
-};
-
 struct Statistics {
   uint64_t num_vertex;           //!< Sum of vertexes in every database
   uint64_t num_edges;            //!< Sum of edges in every database
@@ -110,8 +106,8 @@ class DbmsHandler {
    * @param auth pointer to the global authenticator
    * @param recovery_on_startup restore databases (and its content) and authentication data
    */
-  DbmsHandler(storage::Config config,
-              memgraph::utils::Synchronized<memgraph::auth::Auth, memgraph::utils::WritePrioritizedRWLock> *auth,
+  DbmsHandler(storage::Config config, memgraph::system::System &system, replication::ReplicationState &repl_state,
+              auth::SynchedAuth &auth,
               bool recovery_on_startup);  // TODO If more arguments are added use a config struct
 #else
   /**
@@ -119,15 +115,14 @@ class DbmsHandler {
    *
    * @param configs storage configuration
    */
-  DbmsHandler(storage::Config config)
-      : repl_state_{ReplicationStateRootPath(config)},
+  DbmsHandler(storage::Config config, memgraph::system::System &system, replication::ReplicationState &repl_state)
+      : repl_state_{repl_state},
+        system_{&system},
         db_gatekeeper_{[&] {
                          config.salient.name = kDefaultDB;
                          return std::move(config);
                        }(),
-                       repl_state_} {
-    RecoverReplication(Get());
-  }
+                       repl_state_} {}
 #endif
 
 #ifdef MG_ENTERPRISE
@@ -137,10 +132,10 @@ class DbmsHandler {
    * @param name name of the database
    * @return NewResultT context on success, error on failure
    */
-  NewResultT New(const std::string &name) {
+  NewResultT New(const std::string &name, system::Transaction *txn = nullptr) {
     std::lock_guard<LockT> wr(lock_);
     const auto uuid = utils::UUID{};
-    return New_(name, uuid);
+    return New_(name, uuid, txn);
   }
 
   /**
@@ -233,7 +228,7 @@ class DbmsHandler {
    * @param db_name database name
    * @return DeleteResult error on failure
    */
-  DeleteResult TryDelete(std::string_view db_name);
+  DeleteResult TryDelete(std::string_view db_name, system::Transaction *transaction = nullptr);
 
   /**
    * @brief Delete or defer deletion of database.
@@ -266,19 +261,12 @@ class DbmsHandler {
 #endif
   }
 
-  replication::ReplicationState &ReplicationState() { return repl_state_; }
-  replication::ReplicationState const &ReplicationState() const { return repl_state_; }
-
-  bool IsMain() const { return repl_state_.IsMain(); }
-  bool IsReplica() const { return repl_state_.IsReplica(); }
-
   /**
    * @brief Return the statistics all databases.
    *
    * @return Statistics
    */
-  Statistics Stats() {
-    auto const replication_role = repl_state_.GetRole();
+  Statistics Stats(memgraph::replication_coordination_glue::ReplicationRole replication_role) {
     Statistics stats{};
     // TODO: Handle overflow?
 #ifdef MG_ENTERPRISE
@@ -314,8 +302,7 @@ class DbmsHandler {
    *
    * @return std::vector<DatabaseInfo>
    */
-  std::vector<DatabaseInfo> Info() {
-    auto const replication_role = repl_state_.GetRole();
+  std::vector<DatabaseInfo> Info(memgraph::replication_coordination_glue::ReplicationRole replication_role) {
     std::vector<DatabaseInfo> res;
 #ifdef MG_ENTERPRISE
     std::shared_lock<LockT> rd(lock_);
@@ -402,98 +389,17 @@ class DbmsHandler {
     }
   }
 
-  void NewSystemTransaction() {
-    DMG_ASSERT(!system_transaction_, "Already running a system transaction");
-    system_transaction_.emplace(++system_timestamp_);
-  }
-
-  void ResetSystemTransaction() { system_transaction_.reset(); }
-
-  //! \tparam RPC An rpc::RequestResponse
-  //! \tparam Args the args type
-  //! \param client the client to use for rpc communication
-  //! \param check predicate to check response is ok
-  //! \param args arguments to forward to the rpc request
-  //! \return If replica stream is completed or enqueued
-  template <typename RPC, typename... Args>
-  bool SteamAndFinalizeDelta(auto &client, auto &&check, Args &&...args) {
-    try {
-      auto stream = client.rpc_client_.template Stream<RPC>(std::forward<Args>(args)...);
-      auto task = [&client, check = std::forward<decltype(check)>(check), stream = std::move(stream)]() mutable {
-        if (stream.IsDefunct()) {
-          client.state_.WithLock([](auto &state) { state = memgraph::replication::ReplicationClient::State::BEHIND; });
-          return false;
-        }
-        try {
-          if (check(stream.AwaitResponse())) {
-            return true;
-          }
-        } catch (memgraph::rpc::GenericRpcFailedException const &e) {
-          // swallow error, fallthrough to error handling
-        }
-        // This replica needs SYSTEM recovery
-        client.state_.WithLock([](auto &state) { state = memgraph::replication::ReplicationClient::State::BEHIND; });
-        return false;
-      };
-
-      if (client.mode_ == memgraph::replication::ReplicationMode::ASYNC) {
-        client.thread_pool_.AddTask([task = utils::CopyMovableFunctionWrapper{std::move(task)}]() mutable { task(); });
-        return true;
-      }
-
-      return task();
-    } catch (memgraph::rpc::GenericRpcFailedException const &e) {
-      // This replica needs SYSTEM recovery
-      client.state_.WithLock([](auto &state) { state = memgraph::replication::ReplicationClient::State::BEHIND; });
-      return false;
-    }
-  };
-
-  AllSyncReplicaStatus Commit();
-
-  auto LastCommitedTS() const -> uint64_t { return last_commited_system_timestamp_; }
-  void SetLastCommitedTS(uint64_t new_ts) { last_commited_system_timestamp_.store(new_ts); }
+  static void RecoverStorageReplication(DatabaseAccess db_acc, replication::RoleMainData &role_main_data);
 
+  auto default_config() const -> storage::Config const & {
 #ifdef MG_ENTERPRISE
-  // When being called by intepreter no need to gain lock, it should already be under a system transaction
-  // But concurrently the FrequentCheck is running and will need to lock before reading last_commited_system_timestamp_
-  template <bool REQUIRE_LOCK = false>
-  void SystemRestore(replication::ReplicationClient &client) {
-    // Check if system is up to date
-    if (client.state_.WithLock(
-            [](auto &state) { return state == memgraph::replication::ReplicationClient::State::READY; }))
-      return;
-
-    // Try to recover...
-    {
-      auto [database_configs, last_commited_system_timestamp] = std::invoke([&] {
-        auto sys_guard =
-            std::unique_lock{system_lock_, std::defer_lock};  // ensure no other system transaction in progress
-        if constexpr (REQUIRE_LOCK) {
-          sys_guard.lock();
-        }
-        auto configs = std::vector<storage::SalientConfig>{};
-        ForEach([&configs](DatabaseAccess acc) { configs.emplace_back(acc->config().salient); });
-        return std::pair{configs, last_commited_system_timestamp_.load()};
-      });
-      try {
-        auto stream = client.rpc_client_.Stream<storage::replication::SystemRecoveryRpc>(last_commited_system_timestamp,
-                                                                                         std::move(database_configs));
-        const auto response = stream.AwaitResponse();
-        if (response.result == storage::replication::SystemRecoveryRes::Result::FAILURE) {
-          client.state_.WithLock([](auto &state) { state = memgraph::replication::ReplicationClient::State::BEHIND; });
-          return;
-        }
-      } catch (memgraph::rpc::GenericRpcFailedException const &e) {
-        client.state_.WithLock([](auto &state) { state = memgraph::replication::ReplicationClient::State::BEHIND; });
-        return;
-      }
-    }
-
-    // Successfully recovered
-    client.state_.WithLock([](auto &state) { state = memgraph::replication::ReplicationClient::State::READY; });
-  }
+    return default_config_;
+#else
+    const auto acc = db_gatekeeper_.access();
+    MG_ASSERT(acc, "Failed to get default database!");
+    return acc->get()->config();
 #endif
+  }
 
  private:
 #ifdef MG_ENTERPRISE
@@ -519,7 +425,8 @@ class DbmsHandler {
    * @param uuid undelying RocksDB directory
    * @return NewResultT context on success, error on failure
    */
-  NewResultT New_(std::string_view name, utils::UUID uuid, std::optional<std::filesystem::path> rel_dir = {}) {
+  NewResultT New_(std::string_view name, utils::UUID uuid, system::Transaction *txn = nullptr,
+                  std::optional<std::filesystem::path> rel_dir = {}) {
     auto config_copy = default_config_;
     config_copy.salient.name = name;
     config_copy.salient.uuid = uuid;
@@ -530,7 +437,7 @@ class DbmsHandler {
       storage::UpdatePaths(config_copy,
                            default_config_.durability.storage_directory / kMultiTenantDir / std::string{uuid});
     }
-    return New_(std::move(config_copy));
+    return New_(std::move(config_copy), txn);
   }
 
   /**
@@ -539,11 +446,11 @@ class DbmsHandler {
    * @param config configuration to be used
    * @return NewResultT context on success, error on failure
    */
-  NewResultT New_(const storage::SalientConfig &config) {
+  NewResultT New_(const storage::SalientConfig &config, system::Transaction *txn = nullptr) {
     auto config_copy = default_config_;
     config_copy.salient = config;  // name, uuid, mode, etc
     UpdatePaths(config_copy, config_copy.durability.storage_directory / kMultiTenantDir / std::string{config.uuid});
-    return New_(std::move(config_copy));
+    return New_(std::move(config_copy), txn);
   }
 
   /**
@@ -552,7 +459,7 @@ class DbmsHandler {
    * @param storage_config storage configuration
    * @return NewResultT context on success, error on failure
    */
-  NewResultT New_(storage::Config storage_config);
+  DbmsHandler::NewResultT New_(storage::Config storage_config, system::Transaction *txn = nullptr);
 
   // TODO: new overload of Delete_ with DatabaseAccess
   DeleteResult Delete_(std::string_view db_name);
@@ -567,7 +474,8 @@ class DbmsHandler {
       Get(kDefaultDB);
     } catch (const UnknownDatabaseException &) {
       // No default DB restored, create it
-      MG_ASSERT(New_(kDefaultDB, {/* random UUID */}, ".").HasValue(), "Failed while creating the default database");
+      MG_ASSERT(New_(kDefaultDB, {/* random UUID */}, nullptr, ".").HasValue(),
+                "Failed while creating the default database");
     }
 
     // For back-compatibility...
@@ -654,34 +562,24 @@ class DbmsHandler {
   }
 #endif
 
-  void RecoverReplication(DatabaseAccess db_acc) {
-    if (allow_mt_repl || db_acc->name() == dbms::kDefaultDB) {
-      // Handle global replication state
-      spdlog::info("Replication configuration will be stored and will be automatically restored in case of a crash.");
-      // RECOVER REPLICA CONNECTIONS
-      memgraph::dbms::RestoreReplication(repl_state_, std::move(db_acc));
-    } else if (const ::memgraph::replication::RoleMainData *data =
-                   std::get_if<::memgraph::replication::RoleMainData>(&repl_state_.ReplicationData());
-               data && !data->registered_replicas_.empty()) {
-      spdlog::warn("Multi-tenant replication is currently not supported!");
-    }
-  }
-
 #ifdef MG_ENTERPRISE
   mutable LockT lock_{utils::RWLock::Priority::READ};  //!< protective lock
   storage::Config default_config_;                     //!< Storage configuration used when creating new databases
   DatabaseHandler db_handler_;                         //!< multi-tenancy storage handler
-  std::unique_ptr<kvstore::KVStore> durability_;       //!< list of active dbs (pointer so we can postpone its creation)
+  // TODO: move to be common
+  std::unique_ptr<kvstore::KVStore> durability_;  //!< list of active dbs (pointer so we can postpone its creation)
+  auth::SynchedAuth &auth_;                       //!< Synchronized auth::Auth
 #endif
-  // TODO: Make an api
- public:
-  utils::ResourceLock system_lock_{};  //!> Ensure exclusive access for system queries
  private:
-  std::optional<SystemTransaction> system_transaction_;      //!< Current system transaction (only one at a time)
-  uint64_t system_timestamp_{storage::kTimestampInitialId};  //!< System timestamp
-  std::atomic_uint64_t last_commited_system_timestamp_{
-      storage::kTimestampInitialId};          //!< Last commited system timestamp
-  replication::ReplicationState repl_state_;  //!< Global replication state
+  // NOTE: atm the only reason this exists here, is because we pass it into the construction of New Database's
+  //       Database only uses it as a convience to make the correct Access without out needing to be told the
+  //       current replication role. TODO: make Database Access explicit about the role and remove this from
+  //       dbms stuff
+  replication::ReplicationState &repl_state_;  //!< Ref to global replication state
+ public:
+  // TODO fix to be non public/remove from dbms....maybe
+  system::System *system_;
+
 #ifndef MG_ENTERPRISE
   mutable utils::Gatekeeper<Database> db_gatekeeper_;  //!< Single databases gatekeeper
 #endif

src/dbms/inmemory/replication_handlers.cpp

@@ -23,7 +23,7 @@
 #include "storage/v2/inmemory/storage.hpp"
 #include "storage/v2/inmemory/unique_constraints.hpp"
 
-using memgraph::replication::ReplicationRole;
+using memgraph::replication_coordination_glue::ReplicationRole;
 using memgraph::storage::Delta;
 using memgraph::storage::EdgeAccessor;
 using memgraph::storage::EdgeRef;

src/dbms/inmemory/storage_helper.hpp

@@ -11,10 +11,6 @@
 
 #pragma once
 
-#include <variant>
-
-#include "dbms/constants.hpp"
-#include "dbms/replication_handler.hpp"
 #include "replication/state.hpp"
 #include "storage/v2/config.hpp"
 #include "storage/v2/inmemory/storage.hpp"

src/dbms/replication_client.cpp

@@ -1,43 +0,0 @@
-// Copyright 2024 Memgraph Ltd.
-//
-// Use of this software is governed by the Business Source License
-// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
-// License, and you may not use this file except in compliance with the Business Source License.
-//
-// As of the Change Date specified in that file, in accordance with
-// the Business Source License, use of this software will be governed
-// by the Apache License, Version 2.0, included in the file
-// licenses/APL.txt.
-
-#include "dbms/replication_client.hpp"
-#include "replication/replication_client.hpp"
-
-namespace memgraph::dbms {
-
-void StartReplicaClient(DbmsHandler &dbms_handler, replication::ReplicationClient &client) {
-  // No client error, start instance level client
-  auto const &endpoint = client.rpc_client_.Endpoint();
-  spdlog::trace("Replication client started at: {}:{}", endpoint.address, endpoint.port);
-  client.StartFrequentCheck([&dbms_handler](bool reconnect, replication::ReplicationClient &client) {
-    // Working connection
-    // Check if system needs restoration
-    if (reconnect) {
-      client.state_.WithLock([](auto &state) { state = memgraph::replication::ReplicationClient::State::BEHIND; });
-    }
-#ifdef MG_ENTERPRISE
-    dbms_handler.SystemRestore<true>(client);
-#endif
-    // Check if any database has been left behind
-    dbms_handler.ForEach([&name = client.name_, reconnect](dbms::DatabaseAccess db_acc) {
-      // Specific database <-> replica client
-      db_acc->storage()->repl_storage_state_.WithClient(name, [&](storage::ReplicationStorageClient *client) {
-        if (reconnect || client->State() == storage::replication::ReplicaState::MAYBE_BEHIND) {
-          // Database <-> replica might be behind, check and recover
-          client->TryCheckReplicaStateAsync(db_acc->storage(), db_acc);
-        }
-      });
-    });
-  });
-}  // namespace memgraph::dbms
-
-}  // namespace memgraph::dbms

src/dbms/replication_handler.cpp

@@ -1,441 +0,0 @@
-// Copyright 2024 Memgraph Ltd.
-//
-// Use of this software is governed by the Business Source License
-// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
-// License, and you may not use this file except in compliance with the Business Source License.
-//
-// As of the Change Date specified in that file, in accordance with
-// the Business Source License, use of this software will be governed
-// by the Apache License, Version 2.0, included in the file
-// licenses/APL.txt.
-
-#include "dbms/replication_handler.hpp"
-
-#include <algorithm>
-
-#include "dbms/constants.hpp"
-#include "dbms/dbms_handler.hpp"
-#include "dbms/global.hpp"
-#include "dbms/inmemory/replication_handlers.hpp"
-#include "dbms/replication_client.hpp"
-#include "replication/state.hpp"
-#include "spdlog/spdlog.h"
-#include "storage/v2/config.hpp"
-#include "storage/v2/replication/rpc.hpp"
-#include "utils/on_scope_exit.hpp"
-
-using memgraph::replication::ReplicationClientConfig;
-using memgraph::replication::ReplicationState;
-using memgraph::replication::RoleMainData;
-using memgraph::replication::RoleReplicaData;
-
-namespace memgraph::dbms {
-
-namespace {
-
-std::string RegisterReplicaErrorToString(RegisterReplicaError error) {
-  switch (error) {
-    using enum RegisterReplicaError;
-    case NAME_EXISTS:
-      return "NAME_EXISTS";
-    case END_POINT_EXISTS:
-      return "END_POINT_EXISTS";
-    case CONNECTION_FAILED:
-      return "CONNECTION_FAILED";
-    case COULD_NOT_BE_PERSISTED:
-      return "COULD_NOT_BE_PERSISTED";
-  }
-}
-}  // namespace
-
-ReplicationHandler::ReplicationHandler(DbmsHandler &dbms_handler) : dbms_handler_(dbms_handler) {}
-
-bool ReplicationHandler::SetReplicationRoleMain() {
-  auto const main_handler = [](RoleMainData const &) {
-    // If we are already MAIN, we don't want to change anything
-    return false;
-  };
-  auto const replica_handler = [this](RoleReplicaData const &) {
-    // STEP 1) bring down all REPLICA servers
-    dbms_handler_.ForEach([](DatabaseAccess db_acc) {
-      auto *storage = db_acc->storage();
-      // Remember old epoch + storage timestamp association
-      storage->PrepareForNewEpoch();
-    });
-
-    // STEP 2) Change to MAIN
-    // TODO: restore replication servers if false?
-    if (!dbms_handler_.ReplicationState().SetReplicationRoleMain()) {
-      // TODO: Handle recovery on failure???
-      return false;
-    }
-
-    // STEP 3) We are now MAIN, update storage local epoch
-    const auto &epoch =
-        std::get<RoleMainData>(std::as_const(dbms_handler_.ReplicationState()).ReplicationData()).epoch_;
-    dbms_handler_.ForEach([&](DatabaseAccess db_acc) {
-      auto *storage = db_acc->storage();
-      storage->repl_storage_state_.epoch_ = epoch;
-    });
-
-    return true;
-  };
-
-  // TODO: under lock
-  return std::visit(utils::Overloaded{main_handler, replica_handler},
-                    dbms_handler_.ReplicationState().ReplicationData());
-}
-
-bool ReplicationHandler::SetReplicationRoleReplica(const memgraph::replication::ReplicationServerConfig &config) {
-  // We don't want to restart the server if we're already a REPLICA
-  if (dbms_handler_.ReplicationState().IsReplica()) {
-    return false;
-  }
-
-  // TODO StorageState needs to be synched. Could have a dangling reference if someone adds a database as we are
-  //      deleting the replica.
-  // Remove database specific clients
-  dbms_handler_.ForEach([&](DatabaseAccess db_acc) {
-    auto *storage = db_acc->storage();
-    storage->repl_storage_state_.replication_clients_.WithLock([](auto &clients) { clients.clear(); });
-  });
-  // Remove instance level clients
-  std::get<RoleMainData>(dbms_handler_.ReplicationState().ReplicationData()).registered_replicas_.clear();
-
-  // Creates the server
-  dbms_handler_.ReplicationState().SetReplicationRoleReplica(config);
-
-  // Start
-  const auto success =
-      std::visit(utils::Overloaded{[](RoleMainData const &) {
-                                     // ASSERT
-                                     return false;
-                                   },
-                                   [this](RoleReplicaData const &data) { return StartRpcServer(dbms_handler_, data); }},
-                 dbms_handler_.ReplicationState().ReplicationData());
-  // TODO Handle error (restore to main?)
-  return success;
-}
-
-auto ReplicationHandler::RegisterReplica(const memgraph::replication::ReplicationClientConfig &config)
-    -> memgraph::utils::BasicResult<RegisterReplicaError> {
-  MG_ASSERT(dbms_handler_.ReplicationState().IsMain(), "Only main instance can register a replica!");
-
-  auto instance_client = dbms_handler_.ReplicationState().RegisterReplica(config);
-  if (instance_client.HasError()) {
-    switch (instance_client.GetError()) {
-      case memgraph::replication::RegisterReplicaError::NOT_MAIN:
-        MG_ASSERT(false, "Only main instance can register a replica!");
-        return {};
-      case memgraph::replication::RegisterReplicaError::NAME_EXISTS:
-        return memgraph::dbms::RegisterReplicaError::NAME_EXISTS;
-      case memgraph::replication::RegisterReplicaError::END_POINT_EXISTS:
-        return memgraph::dbms::RegisterReplicaError::END_POINT_EXISTS;
-      case memgraph::replication::RegisterReplicaError::COULD_NOT_BE_PERSISTED:
-        return memgraph::dbms::RegisterReplicaError::COULD_NOT_BE_PERSISTED;
-      case memgraph::replication::RegisterReplicaError::SUCCESS:
-        break;
-    }
-  }
-
-  if (!allow_mt_repl && dbms_handler_.All().size() > 1) {
-    spdlog::warn("Multi-tenant replication is currently not supported!");
-  }
-
-#ifdef MG_ENTERPRISE
-  // Update system before enabling individual storage <-> replica clients
-  dbms_handler_.SystemRestore(*instance_client.GetValue());
-#endif
-
-  bool all_clients_good = true;
-
-  // Add database specific clients (NOTE Currently all databases are connected to each replica)
-  dbms_handler_.ForEach([&](DatabaseAccess db_acc) {
-    auto *storage = db_acc->storage();
-    if (!allow_mt_repl && storage->name() != kDefaultDB) {
-      return;
-    }
-    // TODO: ATM only IN_MEMORY_TRANSACTIONAL, fix other modes
-    if (storage->storage_mode_ != storage::StorageMode::IN_MEMORY_TRANSACTIONAL) return;
-
-    all_clients_good &= storage->repl_storage_state_.replication_clients_.WithLock(
-        [storage, &instance_client, db_acc = std::move(db_acc)](auto &storage_clients) mutable {  // NOLINT
-          auto client = std::make_unique<storage::ReplicationStorageClient>(*instance_client.GetValue());
-          // All good, start replica client
-          client->Start(storage, std::move(db_acc));
-          // After start the storage <-> replica state should be READY or RECOVERING (if correctly started)
-          // MAYBE_BEHIND isn't a statement of the current state, this is the default value
-          // Failed to start due an error like branching of MAIN and REPLICA
-          if (client->State() == storage::replication::ReplicaState::MAYBE_BEHIND) {
-            return false;
-          }
-          storage_clients.push_back(std::move(client));
-          return true;
-        });
-  });
-
-  // NOTE Currently if any databases fails, we revert back
-  if (!all_clients_good) {
-    spdlog::error("Failed to register all databases on the REPLICA \"{}\"", config.name);
-    UnregisterReplica(config.name);
-    return RegisterReplicaError::CONNECTION_FAILED;
-  }
-
-  // No client error, start instance level client
-  StartReplicaClient(dbms_handler_, *instance_client.GetValue());
-  return {};
-}
-
-auto ReplicationHandler::UnregisterReplica(std::string_view name) -> UnregisterReplicaResult {
-  auto const replica_handler = [](RoleReplicaData const &) -> UnregisterReplicaResult {
-    return UnregisterReplicaResult::NOT_MAIN;
-  };
-  auto const main_handler = [this, name](RoleMainData &mainData) -> UnregisterReplicaResult {
-    if (!dbms_handler_.ReplicationState().TryPersistUnregisterReplica(name)) {
-      return UnregisterReplicaResult::COULD_NOT_BE_PERSISTED;
-    }
-    // Remove database specific clients
-    dbms_handler_.ForEach([name](DatabaseAccess db_acc) {
-      db_acc->storage()->repl_storage_state_.replication_clients_.WithLock([&name](auto &clients) {
-        std::erase_if(clients, [name](const auto &client) { return client->Name() == name; });
-      });
-    });
-    // Remove instance level clients
-    auto const n_unregistered =
-        std::erase_if(mainData.registered_replicas_, [name](auto const &client) { return client.name_ == name; });
-    return n_unregistered != 0 ? UnregisterReplicaResult::SUCCESS : UnregisterReplicaResult::CAN_NOT_UNREGISTER;
-  };
-
-  return std::visit(utils::Overloaded{main_handler, replica_handler},
-                    dbms_handler_.ReplicationState().ReplicationData());
-}
-
-auto ReplicationHandler::GetRole() const -> memgraph::replication::ReplicationRole {
-  return dbms_handler_.ReplicationState().GetRole();
-}
-
-bool ReplicationHandler::IsMain() const { return dbms_handler_.ReplicationState().IsMain(); }
-
-bool ReplicationHandler::IsReplica() const { return dbms_handler_.ReplicationState().IsReplica(); }
-
-// Per storage
-// NOTE Storage will connect to all replicas. Future work might change this
-void RestoreReplication(replication::ReplicationState &repl_state, DatabaseAccess db_acc) {
-  spdlog::info("Restoring replication role.");
-
-  /// MAIN
-  auto const recover_main = [db_acc = std::move(db_acc)](RoleMainData &mainData) mutable {  // NOLINT
-    // Each individual client has already been restored and started. Here we just go through each database and start its
-    // client
-    for (auto &instance_client : mainData.registered_replicas_) {
-      spdlog::info("Replica {} restoration started for {}.", instance_client.name_, db_acc->name());
-      const auto &ret = db_acc->storage()->repl_storage_state_.replication_clients_.WithLock(
-          [&, db_acc](auto &storage_clients) mutable -> utils::BasicResult<RegisterReplicaError> {
-            auto client = std::make_unique<storage::ReplicationStorageClient>(instance_client);
-            auto *storage = db_acc->storage();
-            client->Start(storage, std::move(db_acc));
-            // After start the storage <-> replica state should be READY or RECOVERING (if correctly started)
-            // MAYBE_BEHIND isn't a statement of the current state, this is the default value
-            // Failed to start due to branching of MAIN and REPLICA
-            if (client->State() == storage::replication::ReplicaState::MAYBE_BEHIND) {
-              spdlog::warn("Connection failed when registering replica {}. Replica will still be registered.",
-                           instance_client.name_);
-            }
-            storage_clients.push_back(std::move(client));
-            return {};
-          });
-
-      if (ret.HasError()) {
-        MG_ASSERT(RegisterReplicaError::CONNECTION_FAILED != ret.GetError());
-        LOG_FATAL("Failure when restoring replica {}: {}.", instance_client.name_,
-                  RegisterReplicaErrorToString(ret.GetError()));
-      }
-      spdlog::info("Replica {} restored for {}.", instance_client.name_, db_acc->name());
-    }
-    spdlog::info("Replication role restored to MAIN.");
-  };
-
-  /// REPLICA
-  auto const recover_replica = [](RoleReplicaData const &data) { /*nothing to do*/ };
-
-  std::visit(
-      utils::Overloaded{
-          recover_main,
-          recover_replica,
-      },
-      repl_state.ReplicationData());
-}
-
-namespace system_replication {
-#ifdef MG_ENTERPRISE
-void SystemHeartbeatHandler(const uint64_t ts, slk::Reader *req_reader, slk::Builder *res_builder) {
-  replication::SystemHeartbeatReq req;
-  replication::SystemHeartbeatReq::Load(&req, req_reader);
-
-  replication::SystemHeartbeatRes res(ts);
-  memgraph::slk::Save(res, res_builder);
-}
-
-void CreateDatabaseHandler(DbmsHandler &dbms_handler, slk::Reader *req_reader, slk::Builder *res_builder) {
-  memgraph::storage::replication::CreateDatabaseReq req;
-  memgraph::slk::Load(&req, req_reader);
-
-  using memgraph::storage::replication::CreateDatabaseRes;
-  CreateDatabaseRes res(CreateDatabaseRes::Result::FAILURE);
-
-  // Note: No need to check epoch, recovery mechanism is done by a full uptodate snapshot
-  //       of the set of databases. Hence no history exists to maintain regarding epoch change.
-  //       If MAIN has changed we need to check this new group_timestamp is consistent with
-  //       what we have so far.
-
-  if (req.expected_group_timestamp != dbms_handler.LastCommitedTS()) {
-    spdlog::debug("CreateDatabaseHandler: bad expected timestamp {},{}", req.expected_group_timestamp,
-                  dbms_handler.LastCommitedTS());
-    memgraph::slk::Save(res, res_builder);
-    return;
-  }
-
-  try {
-    // Create new
-    auto new_db = dbms_handler.Update(req.config);
-    if (new_db.HasValue()) {
-      // Successfully create db
-      dbms_handler.SetLastCommitedTS(req.new_group_timestamp);
-      res = CreateDatabaseRes(CreateDatabaseRes::Result::SUCCESS);
-      spdlog::debug("CreateDatabaseHandler: SUCCESS updated LCTS to {}", req.new_group_timestamp);
-    }
-  } catch (...) {
-    // Failure
-  }
-
-  memgraph::slk::Save(res, res_builder);
-}
-
-void DropDatabaseHandler(DbmsHandler &dbms_handler, slk::Reader *req_reader, slk::Builder *res_builder) {
-  memgraph::storage::replication::DropDatabaseReq req;
-  memgraph::slk::Load(&req, req_reader);
-
-  using memgraph::storage::replication::DropDatabaseRes;
-  DropDatabaseRes res(DropDatabaseRes::Result::FAILURE);
-
-  // Note: No need to check epoch, recovery mechanism is done by a full uptodate snapshot
-  //       of the set of databases. Hence no history exists to maintain regarding epoch change.
-  //       If MAIN has changed we need to check this new group_timestamp is consistent with
-  //       what we have so far.
-
-  if (req.expected_group_timestamp != dbms_handler.LastCommitedTS()) {
-    spdlog::debug("DropDatabaseHandler: bad expected timestamp {},{}", req.expected_group_timestamp,
-                  dbms_handler.LastCommitedTS());
-    memgraph::slk::Save(res, res_builder);
-    return;
-  }
-
-  try {
-    // NOTE: Single communication channel can exist at a time, no other database can be deleted/created aat the moment.
-    auto new_db = dbms_handler.Delete(req.uuid);
-    if (new_db.HasError()) {
-      if (new_db.GetError() == DeleteError::NON_EXISTENT) {
-        // Nothing to drop
-        dbms_handler.SetLastCommitedTS(req.new_group_timestamp);
-        res = DropDatabaseRes(DropDatabaseRes::Result::NO_NEED);
-      }
-    } else {
-      // Successfully drop db
-      dbms_handler.SetLastCommitedTS(req.new_group_timestamp);
-      res = DropDatabaseRes(DropDatabaseRes::Result::SUCCESS);
-      spdlog::debug("DropDatabaseHandler: SUCCESS updated LCTS to {}", req.new_group_timestamp);
-    }
-  } catch (...) {
-    // Failure
-  }
-
-  memgraph::slk::Save(res, res_builder);
-}
-
-void SystemRecoveryHandler(DbmsHandler &dbms_handler, slk::Reader *req_reader, slk::Builder *res_builder) {
-  // TODO Speed up
-  memgraph::storage::replication::SystemRecoveryReq req;
-  memgraph::slk::Load(&req, req_reader);
-
-  using memgraph::storage::replication::SystemRecoveryRes;
-  SystemRecoveryRes res(SystemRecoveryRes::Result::FAILURE);
-
-  utils::OnScopeExit send_on_exit([&]() { memgraph::slk::Save(res, res_builder); });
-
-  // Get all current dbs
-  auto old = dbms_handler.All();
-
-  // Check/create the incoming dbs
-  for (const auto &config : req.database_configs) {
-    // Missing db
-    try {
-      if (dbms_handler.Update(config).HasError()) {
-        spdlog::debug("SystemRecoveryHandler: Failed to update database \"{}\".", config.name);
-        return;  // Send failure on exit
-      }
-    } catch (const UnknownDatabaseException &) {
-      spdlog::debug("SystemRecoveryHandler: UnknownDatabaseException");
-      return;  // Send failure on exit
-    }
-    const auto it = std::find(old.begin(), old.end(), config.name);
-    if (it != old.end()) old.erase(it);
-  }
-
-  // Delete all the leftover old dbs
-  for (const auto &remove_db : old) {
-    const auto del = dbms_handler.Delete(remove_db);
-    if (del.HasError()) {
-      // Some errors are not terminal
-      if (del.GetError() == DeleteError::DEFAULT_DB || del.GetError() == DeleteError::NON_EXISTENT) {
-        spdlog::debug("SystemRecoveryHandler: Dropped database \"{}\".", remove_db);
-        continue;
-      }
-      spdlog::debug("SystemRecoveryHandler: Failed to drop database \"{}\".", remove_db);
-      return;  // Send failure on exit
-    }
-  }
-  // Successfully recovered
-  dbms_handler.SetLastCommitedTS(req.forced_group_timestamp);
-  spdlog::debug("SystemRecoveryHandler: SUCCESS updated LCTS to {}", req.forced_group_timestamp);
-  res = SystemRecoveryRes(SystemRecoveryRes::Result::SUCCESS);
-}
-#endif
-
-void Register(replication::RoleReplicaData const &data, dbms::DbmsHandler &dbms_handler) {
-#ifdef MG_ENTERPRISE
-  data.server->rpc_server_.Register<replication::SystemHeartbeatRpc>(
-      [&dbms_handler](auto *req_reader, auto *res_builder) {
-        spdlog::debug("Received SystemHeartbeatRpc");
-        SystemHeartbeatHandler(dbms_handler.LastCommitedTS(), req_reader, res_builder);
-      });
-  data.server->rpc_server_.Register<storage::replication::CreateDatabaseRpc>(
-      [&dbms_handler](auto *req_reader, auto *res_builder) {
-        spdlog::debug("Received CreateDatabaseRpc");
-        CreateDatabaseHandler(dbms_handler, req_reader, res_builder);
-      });
-  data.server->rpc_server_.Register<storage::replication::DropDatabaseRpc>(
-      [&dbms_handler](auto *req_reader, auto *res_builder) {
-        spdlog::debug("Received DropDatabaseRpc");
-        DropDatabaseHandler(dbms_handler, req_reader, res_builder);
-      });
-  data.server->rpc_server_.Register<storage::replication::SystemRecoveryRpc>(
-      [&dbms_handler](auto *req_reader, auto *res_builder) {
-        spdlog::debug("Received SystemRecoveryRpc");
-        SystemRecoveryHandler(dbms_handler, req_reader, res_builder);
-      });
-#endif
-}
-}  // namespace system_replication
-
-bool StartRpcServer(DbmsHandler &dbms_handler, const replication::RoleReplicaData &data) {
-  // Register handlers
-  InMemoryReplicationHandlers::Register(&dbms_handler, *data.server);
-  system_replication::Register(data, dbms_handler);
-  // Start server
-  if (!data.server->Start()) {
-    spdlog::error("Unable to start the replication server.");
-    return false;
-  }
-  return true;
-}
-}  // namespace memgraph::dbms

src/dbms/replication_handler.hpp

@@ -1,81 +0,0 @@
-// Copyright 2024 Memgraph Ltd.
-//
-// Use of this software is governed by the Business Source License
-// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
-// License, and you may not use this file except in compliance with the Business Source License.
-//
-// As of the Change Date specified in that file, in accordance with
-// the Business Source License, use of this software will be governed
-// by the Apache License, Version 2.0, included in the file
-// licenses/APL.txt.
-
-#pragma once
-
-#include "dbms/database.hpp"
-#include "replication/role.hpp"
-#include "utils/result.hpp"
-
-// BEGIN fwd declares
-namespace memgraph::replication {
-struct ReplicationState;
-struct ReplicationServerConfig;
-struct ReplicationClientConfig;
-}  // namespace memgraph::replication
-
-namespace memgraph::dbms {
-class DbmsHandler;
-
-enum class RegisterReplicaError : uint8_t { NAME_EXISTS, END_POINT_EXISTS, CONNECTION_FAILED, COULD_NOT_BE_PERSISTED };
-enum class UnregisterReplicaResult : uint8_t {
-  NOT_MAIN,
-  COULD_NOT_BE_PERSISTED,
-  CAN_NOT_UNREGISTER,
-  SUCCESS,
-};
-
-/// A handler type that keep in sync current ReplicationState and the MAIN/REPLICA-ness of Storage
-/// TODO: extend to do multiple storages
-struct ReplicationHandler {
-  explicit ReplicationHandler(DbmsHandler &dbms_handler);
-
-  // as REPLICA, become MAIN
-  bool SetReplicationRoleMain();
-
-  // as MAIN, become REPLICA
-  bool SetReplicationRoleReplica(const memgraph::replication::ReplicationServerConfig &config);
-
-  // as MAIN, define and connect to REPLICAs
-  auto RegisterReplica(const memgraph::replication::ReplicationClientConfig &config)
-      -> utils::BasicResult<RegisterReplicaError>;
-
-  // as MAIN, remove a REPLICA connection
-  auto UnregisterReplica(std::string_view name) -> UnregisterReplicaResult;
-
-  // Helper pass-through (TODO: remove)
-  auto GetRole() const -> memgraph::replication::ReplicationRole;
-  bool IsMain() const;
-  bool IsReplica() const;
-
- private:
-  DbmsHandler &dbms_handler_;
-};
-
-/// A handler type that keep in sync current ReplicationState and the MAIN/REPLICA-ness of Storage
-/// TODO: extend to do multiple storages
-void RestoreReplication(replication::ReplicationState &repl_state, DatabaseAccess db_acc);
-
-namespace system_replication {
-// System handlers
-#ifdef MG_ENTERPRISE
-void CreateDatabaseHandler(DbmsHandler &dbms_handler, slk::Reader *req_reader, slk::Builder *res_builder);
-void SystemHeartbeatHandler(uint64_t ts, slk::Reader *req_reader, slk::Builder *res_builder);
-void SystemRecoveryHandler(DbmsHandler &dbms_handler, slk::Reader *req_reader, slk::Builder *res_builder);
-#endif
-
-/// Register all DBMS level RPC handlers
-void Register(replication::RoleReplicaData const &data, DbmsHandler &dbms_handler);
-}  // namespace system_replication
-
-bool StartRpcServer(DbmsHandler &dbms_handler, const replication::RoleReplicaData &data);
-
-}  // namespace memgraph::dbms

src/dbms/replication_handlers.cpp

@@ -0,0 +1,191 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#include "dbms/replication_handlers.hpp"
+
+#include "dbms/database.hpp"
+#include "dbms/dbms_handler.hpp"
+#include "storage/v2/storage.hpp"
+#include "system/state.hpp"
+
+namespace memgraph::dbms {
+
+#ifdef MG_ENTERPRISE
+
+void CreateDatabaseHandler(memgraph::system::ReplicaHandlerAccessToState &system_state_access,
+                           DbmsHandler &dbms_handler, slk::Reader *req_reader, slk::Builder *res_builder) {
+  using memgraph::storage::replication::CreateDatabaseRes;
+  CreateDatabaseRes res(CreateDatabaseRes::Result::FAILURE);
+
+  // Ignore if no license
+  if (!license::global_license_checker.IsEnterpriseValidFast()) {
+    spdlog::error("Handling CreateDatabase, an enterprise RPC message, without license.");
+    memgraph::slk::Save(res, res_builder);
+    return;
+  }
+
+  memgraph::storage::replication::CreateDatabaseReq req;
+  memgraph::slk::Load(&req, req_reader);
+
+  // Note: No need to check epoch, recovery mechanism is done by a full uptodate snapshot
+  //       of the set of databases. Hence no history exists to maintain regarding epoch change.
+  //       If MAIN has changed we need to check this new group_timestamp is consistent with
+  //       what we have so far.
+
+  if (req.expected_group_timestamp != system_state_access.LastCommitedTS()) {
+    spdlog::debug("CreateDatabaseHandler: bad expected timestamp {},{}", req.expected_group_timestamp,
+                  system_state_access.LastCommitedTS());
+    memgraph::slk::Save(res, res_builder);
+    return;
+  }
+
+  try {
+    // Create new
+    auto new_db = dbms_handler.Update(req.config);
+    if (new_db.HasValue()) {
+      // Successfully create db
+      system_state_access.SetLastCommitedTS(req.new_group_timestamp);
+      res = CreateDatabaseRes(CreateDatabaseRes::Result::SUCCESS);
+      spdlog::debug("CreateDatabaseHandler: SUCCESS updated LCTS to {}", req.new_group_timestamp);
+    }
+  } catch (...) {
+    // Failure
+  }
+
+  memgraph::slk::Save(res, res_builder);
+}
+
+void DropDatabaseHandler(memgraph::system::ReplicaHandlerAccessToState &system_state_access, DbmsHandler &dbms_handler,
+                         slk::Reader *req_reader, slk::Builder *res_builder) {
+  using memgraph::storage::replication::DropDatabaseRes;
+  DropDatabaseRes res(DropDatabaseRes::Result::FAILURE);
+
+  // Ignore if no license
+  if (!license::global_license_checker.IsEnterpriseValidFast()) {
+    spdlog::error("Handling DropDatabase, an enterprise RPC message, without license.");
+    memgraph::slk::Save(res, res_builder);
+    return;
+  }
+
+  memgraph::storage::replication::DropDatabaseReq req;
+  memgraph::slk::Load(&req, req_reader);
+
+  // Note: No need to check epoch, recovery mechanism is done by a full uptodate snapshot
+  //       of the set of databases. Hence no history exists to maintain regarding epoch change.
+  //       If MAIN has changed we need to check this new group_timestamp is consistent with
+  //       what we have so far.
+
+  if (req.expected_group_timestamp != system_state_access.LastCommitedTS()) {
+    spdlog::debug("DropDatabaseHandler: bad expected timestamp {},{}", req.expected_group_timestamp,
+                  system_state_access.LastCommitedTS());
+    memgraph::slk::Save(res, res_builder);
+    return;
+  }
+
+  try {
+    // NOTE: Single communication channel can exist at a time, no other database can be deleted/created at the moment.
+    auto new_db = dbms_handler.Delete(req.uuid);
+    if (new_db.HasError()) {
+      if (new_db.GetError() == DeleteError::NON_EXISTENT) {
+        // Nothing to drop
+        system_state_access.SetLastCommitedTS(req.new_group_timestamp);
+        res = DropDatabaseRes(DropDatabaseRes::Result::NO_NEED);
+      }
+    } else {
+      // Successfully drop db
+      system_state_access.SetLastCommitedTS(req.new_group_timestamp);
+      res = DropDatabaseRes(DropDatabaseRes::Result::SUCCESS);
+      spdlog::debug("DropDatabaseHandler: SUCCESS updated LCTS to {}", req.new_group_timestamp);
+    }
+  } catch (...) {
+    // Failure
+  }
+
+  memgraph::slk::Save(res, res_builder);
+}
+
+bool SystemRecoveryHandler(DbmsHandler &dbms_handler, const std::vector<storage::SalientConfig> &database_configs) {
+  /*
+   * NO LICENSE
+   */
+  if (!license::global_license_checker.IsEnterpriseValidFast()) {
+    spdlog::error("Handling SystemRecovery, an enterprise RPC message, without license.");
+    for (const auto &config : database_configs) {
+      // Only handle default DB
+      if (config.name != kDefaultDB) continue;
+      try {
+        if (dbms_handler.Update(config).HasError()) {
+          return false;
+        }
+      } catch (const UnknownDatabaseException &) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  /*
+   * MULTI-TENANCY
+   */
+  // Get all current dbs
+  auto old = dbms_handler.All();
+  // Check/create the incoming dbs
+  for (const auto &config : database_configs) {
+    // Missing db
+    try {
+      if (dbms_handler.Update(config).HasError()) {
+        spdlog::debug("SystemRecoveryHandler: Failed to update database \"{}\".", config.name);
+        return false;
+      }
+    } catch (const UnknownDatabaseException &) {
+      spdlog::debug("SystemRecoveryHandler: UnknownDatabaseException");
+      return false;
+    }
+    const auto it = std::find(old.begin(), old.end(), config.name);
+    if (it != old.end()) old.erase(it);
+  }
+
+  // Delete all the leftover old dbs
+  for (const auto &remove_db : old) {
+    const auto del = dbms_handler.Delete(remove_db);
+    if (del.HasError()) {
+      // Some errors are not terminal
+      if (del.GetError() == DeleteError::DEFAULT_DB || del.GetError() == DeleteError::NON_EXISTENT) {
+        spdlog::debug("SystemRecoveryHandler: Dropped database \"{}\".", remove_db);
+        continue;
+      }
+      spdlog::debug("SystemRecoveryHandler: Failed to drop database \"{}\".", remove_db);
+      return false;
+    }
+  }
+
+  /*
+   * SUCCESS
+   */
+  return true;
+}
+
+void Register(replication::RoleReplicaData const &data, system::ReplicaHandlerAccessToState &system_state_access,
+              dbms::DbmsHandler &dbms_handler) {
+  // NOTE: Register even without license as the user could add a license at run-time
+  data.server->rpc_server_.Register<storage::replication::CreateDatabaseRpc>(
+      [system_state_access, &dbms_handler](auto *req_reader, auto *res_builder) mutable {
+        spdlog::debug("Received CreateDatabaseRpc");
+        CreateDatabaseHandler(system_state_access, dbms_handler, req_reader, res_builder);
+      });
+  data.server->rpc_server_.Register<storage::replication::DropDatabaseRpc>(
+      [system_state_access, &dbms_handler](auto *req_reader, auto *res_builder) mutable {
+        spdlog::debug("Received DropDatabaseRpc");
+        DropDatabaseHandler(system_state_access, dbms_handler, req_reader, res_builder);
+      });
+}
+#endif
+}  // namespace memgraph::dbms

src/dbms/replication_handlers.hpp

@@ -0,0 +1,32 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#include "dbms/dbms_handler.hpp"
+#include "replication/state.hpp"
+#include "slk/streams.hpp"
+#include "system/state.hpp"
+
+namespace memgraph::dbms {
+#ifdef MG_ENTERPRISE
+// RPC handlers
+void CreateDatabaseHandler(memgraph::system::ReplicaHandlerAccessToState &system_state_access,
+                           DbmsHandler &dbms_handler, slk::Reader *req_reader, slk::Builder *res_builder);
+void DropDatabaseHandler(memgraph::system::ReplicaHandlerAccessToState &system_state_access, DbmsHandler &dbms_handler,
+                         slk::Reader *req_reader, slk::Builder *res_builder);
+bool SystemRecoveryHandler(DbmsHandler &dbms_handler, const std::vector<storage::SalientConfig> &database_configs);
+
+// RPC registration
+void Register(replication::RoleReplicaData const &data, system::ReplicaHandlerAccessToState &system_state_access,
+              dbms::DbmsHandler &dbms_handler);
+#endif
+}  // namespace memgraph::dbms

src/dbms/rpc.cpp

@@ -0,0 +1,118 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#include "dbms/rpc.hpp"
+
+#include "slk/streams.hpp"
+#include "storage/v2/replication/rpc.hpp"
+#include "utils/enum.hpp"
+#include "utils/typeinfo.hpp"
+
+namespace memgraph {
+
+namespace storage::replication {
+
+void CreateDatabaseReq::Save(const CreateDatabaseReq &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self, builder);
+}
+void CreateDatabaseReq::Load(CreateDatabaseReq *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(self, reader);
+}
+void CreateDatabaseRes::Save(const CreateDatabaseRes &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self, builder);
+}
+void CreateDatabaseRes::Load(CreateDatabaseRes *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(self, reader);
+}
+void DropDatabaseReq::Save(const DropDatabaseReq &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self, builder);
+}
+void DropDatabaseReq::Load(DropDatabaseReq *self, memgraph::slk::Reader *reader) { memgraph::slk::Load(self, reader); }
+void DropDatabaseRes::Save(const DropDatabaseRes &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self, builder);
+}
+void DropDatabaseRes::Load(DropDatabaseRes *self, memgraph::slk::Reader *reader) { memgraph::slk::Load(self, reader); }
+
+const utils::TypeInfo CreateDatabaseReq::kType{utils::TypeId::REP_CREATE_DATABASE_REQ, "CreateDatabaseReq", nullptr};
+
+const utils::TypeInfo CreateDatabaseRes::kType{utils::TypeId::REP_CREATE_DATABASE_RES, "CreateDatabaseRes", nullptr};
+
+const utils::TypeInfo DropDatabaseReq::kType{utils::TypeId::REP_DROP_DATABASE_REQ, "DropDatabaseReq", nullptr};
+
+const utils::TypeInfo DropDatabaseRes::kType{utils::TypeId::REP_DROP_DATABASE_RES, "DropDatabaseRes", nullptr};
+
+}  // namespace storage::replication
+
+// Autogenerated SLK serialization code
+namespace slk {
+
+// Serialize code for CreateDatabaseReq
+
+void Save(const memgraph::storage::replication::CreateDatabaseReq &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self.epoch_id, builder);
+  memgraph::slk::Save(self.expected_group_timestamp, builder);
+  memgraph::slk::Save(self.new_group_timestamp, builder);
+  memgraph::slk::Save(self.config, builder);
+}
+
+void Load(memgraph::storage::replication::CreateDatabaseReq *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(&self->epoch_id, reader);
+  memgraph::slk::Load(&self->expected_group_timestamp, reader);
+  memgraph::slk::Load(&self->new_group_timestamp, reader);
+  memgraph::slk::Load(&self->config, reader);
+}
+
+// Serialize code for CreateDatabaseRes
+
+void Save(const memgraph::storage::replication::CreateDatabaseRes &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(utils::EnumToNum<uint8_t>(self.result), builder);
+}
+
+void Load(memgraph::storage::replication::CreateDatabaseRes *self, memgraph::slk::Reader *reader) {
+  uint8_t res = 0;
+  memgraph::slk::Load(&res, reader);
+  if (!utils::NumToEnum(res, self->result)) {
+    throw SlkReaderException("Unexpected result line:{}!", __LINE__);
+  }
+}
+
+// Serialize code for DropDatabaseReq
+
+void Save(const memgraph::storage::replication::DropDatabaseReq &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self.epoch_id, builder);
+  memgraph::slk::Save(self.expected_group_timestamp, builder);
+  memgraph::slk::Save(self.new_group_timestamp, builder);
+  memgraph::slk::Save(self.uuid, builder);
+}
+
+void Load(memgraph::storage::replication::DropDatabaseReq *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(&self->epoch_id, reader);
+  memgraph::slk::Load(&self->expected_group_timestamp, reader);
+  memgraph::slk::Load(&self->new_group_timestamp, reader);
+  memgraph::slk::Load(&self->uuid, reader);
+}
+
+// Serialize code for DropDatabaseRes
+
+void Save(const memgraph::storage::replication::DropDatabaseRes &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(utils::EnumToNum<uint8_t>(self.result), builder);
+}
+
+void Load(memgraph::storage::replication::DropDatabaseRes *self, memgraph::slk::Reader *reader) {
+  uint8_t res = 0;
+  memgraph::slk::Load(&res, reader);
+  if (!utils::NumToEnum(res, self->result)) {
+    throw SlkReaderException("Unexpected result line:{}!", __LINE__);
+  }
+}
+
+}  // namespace slk
+}  // namespace memgraph

src/dbms/rpc.hpp

@@ -0,0 +1,118 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#include <cstdint>
+#include <string>
+#include <utility>
+
+#include "rpc/messages.hpp"
+#include "slk/streams.hpp"
+#include "storage/v2/config.hpp"
+#include "utils/uuid.hpp"
+
+namespace memgraph::storage::replication {
+
+struct CreateDatabaseReq {
+  static const utils::TypeInfo kType;
+  static const utils::TypeInfo &GetTypeInfo() { return kType; }
+
+  static void Load(CreateDatabaseReq *self, memgraph::slk::Reader *reader);
+  static void Save(const CreateDatabaseReq &self, memgraph::slk::Builder *builder);
+  CreateDatabaseReq() = default;
+  CreateDatabaseReq(std::string_view epoch_id, uint64_t expected_group_timestamp, uint64_t new_group_timestamp,
+                    storage::SalientConfig config)
+      : epoch_id(std::string(epoch_id)),
+        expected_group_timestamp{expected_group_timestamp},
+        new_group_timestamp(new_group_timestamp),
+        config(std::move(config)) {}
+
+  std::string epoch_id;
+  uint64_t expected_group_timestamp;
+  uint64_t new_group_timestamp;
+  storage::SalientConfig config;
+};
+
+struct CreateDatabaseRes {
+  static const utils::TypeInfo kType;
+  static const utils::TypeInfo &GetTypeInfo() { return kType; }
+
+  enum class Result : uint8_t { SUCCESS, NO_NEED, FAILURE, /* Leave at end */ N };
+
+  static void Load(CreateDatabaseRes *self, memgraph::slk::Reader *reader);
+  static void Save(const CreateDatabaseRes &self, memgraph::slk::Builder *builder);
+  CreateDatabaseRes() = default;
+  explicit CreateDatabaseRes(Result res) : result(res) {}
+
+  Result result;
+};
+
+using CreateDatabaseRpc = rpc::RequestResponse<CreateDatabaseReq, CreateDatabaseRes>;
+
+struct DropDatabaseReq {
+  static const utils::TypeInfo kType;
+  static const utils::TypeInfo &GetTypeInfo() { return kType; }
+
+  static void Load(DropDatabaseReq *self, memgraph::slk::Reader *reader);
+  static void Save(const DropDatabaseReq &self, memgraph::slk::Builder *builder);
+  DropDatabaseReq() = default;
+  DropDatabaseReq(std::string_view epoch_id, uint64_t expected_group_timestamp, uint64_t new_group_timestamp,
+                  const utils::UUID &uuid)
+      : epoch_id(std::string(epoch_id)),
+        expected_group_timestamp{expected_group_timestamp},
+        new_group_timestamp(new_group_timestamp),
+        uuid(uuid) {}
+
+  std::string epoch_id;
+  uint64_t expected_group_timestamp;
+  uint64_t new_group_timestamp;
+  utils::UUID uuid;
+};
+
+struct DropDatabaseRes {
+  static const utils::TypeInfo kType;
+  static const utils::TypeInfo &GetTypeInfo() { return kType; }
+
+  enum class Result : uint8_t { SUCCESS, NO_NEED, FAILURE, /* Leave at end */ N };
+
+  static void Load(DropDatabaseRes *self, memgraph::slk::Reader *reader);
+  static void Save(const DropDatabaseRes &self, memgraph::slk::Builder *builder);
+  DropDatabaseRes() = default;
+  explicit DropDatabaseRes(Result res) : result(res) {}
+
+  Result result;
+};
+
+using DropDatabaseRpc = rpc::RequestResponse<DropDatabaseReq, DropDatabaseRes>;
+
+}  // namespace memgraph::storage::replication
+
+// SLK serialization declarations
+namespace memgraph::slk {
+
+void Save(const memgraph::storage::replication::CreateDatabaseReq &self, memgraph::slk::Builder *builder);
+
+void Load(memgraph::storage::replication::CreateDatabaseReq *self, memgraph::slk::Reader *reader);
+
+void Save(const memgraph::storage::replication::CreateDatabaseRes &self, memgraph::slk::Builder *builder);
+
+void Load(memgraph::storage::replication::CreateDatabaseRes *self, memgraph::slk::Reader *reader);
+
+void Save(const memgraph::storage::replication::DropDatabaseReq &self, memgraph::slk::Builder *builder);
+
+void Load(memgraph::storage::replication::DropDatabaseReq *self, memgraph::slk::Reader *reader);
+
+void Save(const memgraph::storage::replication::DropDatabaseRes &self, memgraph::slk::Builder *builder);
+
+void Load(memgraph::storage::replication::DropDatabaseRes *self, memgraph::slk::Reader *reader);
+
+}  // namespace memgraph::slk

src/dbms/transaction.hpp

@@ -11,6 +11,7 @@
 
 #pragma once
 
+#include <list>
 #include <memory>
 #include <optional>
 #include "auth/models.hpp"
@@ -66,6 +67,8 @@ struct SystemTransaction {
     static constexpr struct DropAuthData {
     } drop_auth_data;
 
+    enum class AuthData { USER, ROLE };
+
     // Multi-tenancy
     Delta(CreateDatabase /*tag*/, storage::SalientConfig config)
         : action(Action::CREATE_DATABASE), config(std::move(config)) {}
@@ -76,8 +79,12 @@ struct SystemTransaction {
         : action(Action::UPDATE_AUTH_DATA), auth_data{std::move(user), std::nullopt} {}
     Delta(UpdateAuthData /*tag*/, std::optional<auth::Role> role)
         : action(Action::UPDATE_AUTH_DATA), auth_data{std::nullopt, std::move(role)} {}
-    Delta(DropAuthData /*tag*/, std::string_view auth_data_key)
-        : action(Action::DROP_AUTH_DATA), auth_data_key{auth_data_key} {}
+    Delta(DropAuthData /*tag*/, AuthData type, std::string_view name)
+        : action(Action::DROP_AUTH_DATA),
+          auth_data_key{
+              .type = type,
+              .name = std::string{name},
+          } {}
 
     // Generic
     Delta(const Delta &) = delete;
@@ -110,14 +117,16 @@ struct SystemTransaction {
         std::optional<auth::User> user;
         std::optional<auth::Role> role;
       } auth_data;
-      std::string auth_data_key;
+      struct {
+        AuthData type;
+        std::string name;
+      } auth_data_key;
     };
   };
 
   explicit SystemTransaction(uint64_t timestamp) : system_timestamp(timestamp) {}
 
-  // Currently system transitions support a single delta
-  std::optional<Delta> delta{};  // TODO Vector
+  std::list<Delta> deltas{};
   uint64_t system_timestamp;
 };
 

src/flags/CMakeLists.txt

@@ -6,6 +6,7 @@ add_library(mg-flags STATIC audit.cpp
                             memory_limit.cpp
                             run_time_configurable.cpp
                             storage_mode.cpp
-                            query.cpp)
+                            query.cpp
+                            replication.cpp)
 target_include_directories(mg-flags PUBLIC ${CMAKE_SOURCE_DIR}/include)
 target_link_libraries(mg-flags PUBLIC spdlog::spdlog mg-settings mg-utils)

src/flags/all.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -17,5 +17,6 @@
 #include "flags/log_level.hpp"
 #include "flags/memory_limit.hpp"
 #include "flags/query.hpp"
+#include "flags/replication.hpp"
 #include "flags/run_time_configurable.hpp"
 #include "flags/storage_mode.hpp"

src/flags/general.cpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -156,13 +156,6 @@ DEFINE_string(pulsar_service_url, "", "Default URL used while connecting to Puls
 
 // Query flags.
 
-// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
-DEFINE_uint64(replication_replica_check_frequency_sec, 1,
-              "The time duration between two replica checks/pings. If < 1, replicas will NOT be checked at all. NOTE: "
-              "The MAIN instance allocates a new thread for each REPLICA.");
-// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
-DEFINE_bool(replication_restore_state_on_startup, false, "Restore replication state on startup, e.g. recover replica");
-
 DEFINE_VALIDATED_string(query_modules_directory, "",
                         "Directory where modules with custom query procedures are stored. "
                         "NOTE: Multiple comma-separated directories can be defined.",
@@ -202,3 +195,9 @@ DEFINE_HIDDEN_string(organization_name, "", "Organization name.");
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
 DEFINE_string(auth_user_or_role_name_regex, memgraph::glue::kDefaultUserRoleRegex.data(),
               "Set to the regular expression that each user or role name must fulfill.");
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
+DEFINE_bool(auth_password_permit_null, true, "Set to false to disable null passwords.");
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
+DEFINE_string(auth_password_strength_regex, memgraph::glue::kDefaultPasswordRegex.data(),
+              "The regular expression that should be used to match the entire "
+              "entered password to ensure its strength.");

src/flags/general.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -112,14 +112,13 @@ namespace memgraph::flags {
 auto ParseQueryModulesDirectory() -> std::vector<std::filesystem::path>;
 }  // namespace memgraph::flags
 
-// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
-DECLARE_uint64(replication_replica_check_frequency_sec);
-// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
-DECLARE_bool(replication_restore_state_on_startup);
-
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
 DECLARE_string(license_key);
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
 DECLARE_string(organization_name);
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
 DECLARE_string(auth_user_or_role_name_regex);
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
+DECLARE_bool(auth_password_permit_null);
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
+DECLARE_string(auth_password_strength_regex);

src/flags/replication.cpp

@@ -0,0 +1,26 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#include "replication.hpp"
+
+#ifdef MG_ENTERPRISE
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
+DEFINE_bool(coordinator, false, "Controls whether the instance is a replication coordinator.");
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
+DEFINE_uint32(coordinator_server_port, 0, "Port on which coordinator servers will be started.");
+#endif
+
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
+DEFINE_uint64(replication_replica_check_frequency_sec, 1,
+              "The time duration between two replica checks/pings. If < 1, replicas will NOT be checked at all. NOTE: "
+              "The MAIN instance allocates a new thread for each REPLICA.");
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
+DEFINE_bool(replication_restore_state_on_startup, false, "Restore replication state on startup, e.g. recover replica");

src/flags/replication.hpp

@@ -0,0 +1,26 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#include "gflags/gflags.h"
+
+#ifdef MG_ENTERPRISE
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
+DECLARE_bool(coordinator);
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
+DECLARE_uint32(coordinator_server_port);
+#endif
+
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
+DECLARE_uint64(replication_replica_check_frequency_sec);
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
+DECLARE_bool(replication_restore_state_on_startup);

src/glue/ServerT.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -33,7 +33,7 @@ class WritePrioritizedRWLock;
 
 struct Context {
   memgraph::query::InterpreterContext *ic;
-  memgraph::utils::Synchronized<memgraph::auth::Auth, memgraph::utils::WritePrioritizedRWLock> *auth;
+  memgraph::auth::SynchedAuth *auth;
 #if MG_ENTERPRISE
   memgraph::audit::Log *audit_log;
 #endif

src/glue/SessionHL.cpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -193,12 +193,13 @@ std::pair<std::vector<std::string>, std::optional<int>> SessionHL::Interpret(
   for (const auto &[key, bolt_param] : params) {
     params_pv.emplace(key, ToPropertyValue(bolt_param));
   }
+
+#ifdef MG_ENTERPRISE
   const std::string *username{nullptr};
   if (user_) {
     username = &user_->username();
   }
 
-#ifdef MG_ENTERPRISE
   if (memgraph::license::global_license_checker.IsEnterpriseValidFast()) {
     auto &db = interpreter_.current_db_.db_acc_;
     audit_log_->Record(endpoint_.address().to_string(), user_ ? *username : "", query,
@@ -318,8 +319,7 @@ void SessionHL::Configure(const std::map<std::string, memgraph::communication::b
 SessionHL::SessionHL(memgraph::query::InterpreterContext *interpreter_context,
                      memgraph::communication::v2::ServerEndpoint endpoint,
                      memgraph::communication::v2::InputStream *input_stream,
-                     memgraph::communication::v2::OutputStream *output_stream,
-                     memgraph::utils::Synchronized<memgraph::auth::Auth, memgraph::utils::WritePrioritizedRWLock> *auth
+                     memgraph::communication::v2::OutputStream *output_stream, memgraph::auth::SynchedAuth *auth
 #ifdef MG_ENTERPRISE
                      ,
                      memgraph::audit::Log *audit_log

src/glue/SessionHL.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -25,8 +25,7 @@ class SessionHL final : public memgraph::communication::bolt::Session<memgraph::
   SessionHL(memgraph::query::InterpreterContext *interpreter_context,
             memgraph::communication::v2::ServerEndpoint endpoint,
             memgraph::communication::v2::InputStream *input_stream,
-            memgraph::communication::v2::OutputStream *output_stream,
-            memgraph::utils::Synchronized<memgraph::auth::Auth, memgraph::utils::WritePrioritizedRWLock> *auth
+            memgraph::communication::v2::OutputStream *output_stream, memgraph::auth::SynchedAuth *auth
 #ifdef MG_ENTERPRISE
             ,
             memgraph::audit::Log *audit_log
@@ -88,7 +87,7 @@ class SessionHL final : public memgraph::communication::bolt::Session<memgraph::
   memgraph::audit::Log *audit_log_;
   bool in_explicit_db_{false};  //!< If true, the user has defined the database to use via metadata
 #endif
-  memgraph::utils::Synchronized<memgraph::auth::Auth, memgraph::utils::WritePrioritizedRWLock> *auth_;
+  memgraph::auth::SynchedAuth *auth_;
   memgraph::communication::v2::ServerEndpoint endpoint_;
   std::optional<std::string> implicit_db_;
 };

src/glue/auth.cpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -66,6 +66,8 @@ auth::Permission PrivilegeToPermission(query::AuthQuery::Privilege privilege) {
       return auth::Permission::MULTI_DATABASE_EDIT;
     case query::AuthQuery::Privilege::MULTI_DATABASE_USE:
       return auth::Permission::MULTI_DATABASE_USE;
+    case query::AuthQuery::Privilege::COORDINATOR:
+      return auth::Permission::COORDINATOR;
   }
 }
 

src/glue/auth_checker.cpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -66,9 +66,7 @@ bool IsUserAuthorizedEdgeType(const memgraph::auth::User &user, const memgraph::
 #endif
 namespace memgraph::glue {
 
-AuthChecker::AuthChecker(
-    memgraph::utils::Synchronized<memgraph::auth::Auth, memgraph::utils::WritePrioritizedRWLock> *auth)
-    : auth_(auth) {}
+AuthChecker::AuthChecker(memgraph::auth::SynchedAuth *auth) : auth_(auth) {}
 
 bool AuthChecker::IsUserAuthorized(const std::optional<std::string> &username,
                                    const std::vector<memgraph::query::AuthQuery::Privilege> &privileges,

src/glue/auth_checker.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -22,8 +22,7 @@ namespace memgraph::glue {
 
 class AuthChecker : public query::AuthChecker {
  public:
-  explicit AuthChecker(
-      memgraph::utils::Synchronized<memgraph::auth::Auth, memgraph::utils::WritePrioritizedRWLock> *auth);
+  explicit AuthChecker(memgraph::auth::SynchedAuth *auth);
 
   bool IsUserAuthorized(const std::optional<std::string> &username,
                         const std::vector<query::AuthQuery::Privilege> &privileges,
@@ -41,7 +40,7 @@ class AuthChecker : public query::AuthChecker {
                                              const std::string &db_name = "");
 
  private:
-  memgraph::utils::Synchronized<memgraph::auth::Auth, memgraph::utils::WritePrioritizedRWLock> *auth_;
+  memgraph::auth::SynchedAuth *auth_;
   mutable memgraph::utils::Synchronized<auth::User, memgraph::utils::SpinLock> user_;  // cached user
 };
 #ifdef MG_ENTERPRISE

src/glue/auth_global.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -13,4 +13,5 @@
 
 namespace memgraph::glue {
 inline constexpr std::string_view kDefaultUserRoleRegex = "[a-zA-Z0-9_.+-@]+";
+static constexpr std::string_view kDefaultPasswordRegex = ".+";
 }  // namespace memgraph::glue

src/glue/auth_handler.cpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -210,16 +210,25 @@ std::vector<std::vector<memgraph::query::TypedValue>> ShowFineGrainedUserPrivile
   if (!memgraph::license::global_license_checker.IsEnterpriseValidFast()) {
     return {};
   }
-  const auto &label_permissions = user->GetFineGrainedAccessLabelPermissions();
-  const auto &edge_type_permissions = user->GetFineGrainedAccessEdgeTypePermissions();
 
-  auto all_fine_grained_permissions =
-      GetFineGrainedPermissionForPrivilegeForUserOrRole(label_permissions, "LABEL", "USER");
-  auto edge_type_fine_grained_permissions =
-      GetFineGrainedPermissionForPrivilegeForUserOrRole(edge_type_permissions, "EDGE_TYPE", "USER");
+  auto all_fine_grained_permissions = GetFineGrainedPermissionForPrivilegeForUserOrRole(
+      user->GetUserFineGrainedAccessLabelPermissions(), "LABEL", "USER");
+  auto all_role_fine_grained_permissions = GetFineGrainedPermissionForPrivilegeForUserOrRole(
+      user->GetRoleFineGrainedAccessLabelPermissions(), "LABEL", "ROLE");
+  all_fine_grained_permissions.insert(all_fine_grained_permissions.end(),
+                                      std::make_move_iterator(all_role_fine_grained_permissions.begin()),
+                                      std::make_move_iterator(all_role_fine_grained_permissions.end()));
 
-  all_fine_grained_permissions.insert(all_fine_grained_permissions.end(), edge_type_fine_grained_permissions.begin(),
-                                      edge_type_fine_grained_permissions.end());
+  auto edge_type_fine_grained_permissions = GetFineGrainedPermissionForPrivilegeForUserOrRole(
+      user->GetUserFineGrainedAccessEdgeTypePermissions(), "EDGE_TYPE", "USER");
+  auto role_edge_type_fine_grained_permissions = GetFineGrainedPermissionForPrivilegeForUserOrRole(
+      user->GetRoleFineGrainedAccessEdgeTypePermissions(), "EDGE_TYPE", "ROLE");
+  all_fine_grained_permissions.insert(all_fine_grained_permissions.end(),
+                                      std::make_move_iterator(edge_type_fine_grained_permissions.begin()),
+                                      std::make_move_iterator(edge_type_fine_grained_permissions.end()));
+  all_fine_grained_permissions.insert(all_fine_grained_permissions.end(),
+                                      std::make_move_iterator(role_edge_type_fine_grained_permissions.begin()),
+                                      std::make_move_iterator(role_edge_type_fine_grained_permissions.end()));
 
   return ConstructFineGrainedPrivilegesResult(all_fine_grained_permissions);
 }
@@ -233,9 +242,9 @@ std::vector<std::vector<memgraph::query::TypedValue>> ShowFineGrainedRolePrivile
   const auto &edge_type_permissions = role->GetFineGrainedAccessEdgeTypePermissions();
 
   auto all_fine_grained_permissions =
-      GetFineGrainedPermissionForPrivilegeForUserOrRole(label_permissions, "LABEL", "USER");
+      GetFineGrainedPermissionForPrivilegeForUserOrRole(label_permissions, "LABEL", "ROLE");
   auto edge_type_fine_grained_permissions =
-      GetFineGrainedPermissionForPrivilegeForUserOrRole(edge_type_permissions, "EDGE_TYPE", "USER");
+      GetFineGrainedPermissionForPrivilegeForUserOrRole(edge_type_permissions, "EDGE_TYPE", "ROLE");
 
   all_fine_grained_permissions.insert(all_fine_grained_permissions.end(), edge_type_fine_grained_permissions.begin(),
                                       edge_type_fine_grained_permissions.end());
@@ -248,31 +257,15 @@ std::vector<std::vector<memgraph::query::TypedValue>> ShowFineGrainedRolePrivile
 
 namespace memgraph::glue {
 
-AuthQueryHandler::AuthQueryHandler(
-    memgraph::utils::Synchronized<memgraph::auth::Auth, memgraph::utils::WritePrioritizedRWLock> *auth,
-    std::string name_regex_string)
-    : auth_(auth), name_regex_string_(std::move(name_regex_string)), name_regex_(name_regex_string_) {}
+AuthQueryHandler::AuthQueryHandler(memgraph::auth::SynchedAuth *auth) : auth_(auth) {}
 
-bool AuthQueryHandler::CreateUser(const std::string &username, const std::optional<std::string> &password) {
-  if (name_regex_string_ != kDefaultUserRoleRegex) {
-    if (const auto license_check_result =
-            memgraph::license::global_license_checker.IsEnterpriseValid(memgraph::utils::global_settings);
-        license_check_result.HasError()) {
-      throw memgraph::auth::AuthException(
-          "Custom user/role regex is a Memgraph Enterprise feature. Please set the config "
-          "(\"--auth-user-or-role-name-regex\") to its default value (\"{}\") or remove the flag.\n{}",
-          kDefaultUserRoleRegex,
-          memgraph::license::LicenseCheckErrorToString(license_check_result.GetError(), "user/role regex"));
-    }
-  }
-  if (!std::regex_match(username, name_regex_)) {
-    throw query::QueryRuntimeException("Invalid user name.");
-  }
+bool AuthQueryHandler::CreateUser(const std::string &username, const std::optional<std::string> &password,
+                                  system::Transaction *system_tx) {
   try {
     const auto [first_user, user_added] = std::invoke([&, this] {
       auto locked_auth = auth_->Lock();
       const auto first_user = !locked_auth->HasUsers();
-      const auto user_added = locked_auth->AddUser(username, password).has_value();
+      const auto user_added = locked_auth->AddUser(username, password, system_tx).has_value();
       return std::make_pair(first_user, user_added);
     });
 
@@ -291,10 +284,11 @@ bool AuthQueryHandler::CreateUser(const std::string &username, const std::option
             }
           }
 #endif
-      );
+          ,
+          system_tx);
 #ifdef MG_ENTERPRISE
-      GrantDatabaseToUser(auth::kAllDatabases, username);
-      SetMainDatabase(dbms::kDefaultDB, username);
+      GrantDatabaseToUser(auth::kAllDatabases, username, system_tx);
+      SetMainDatabase(dbms::kDefaultDB, username, system_tx);
 #endif
     }
 
@@ -304,73 +298,61 @@ bool AuthQueryHandler::CreateUser(const std::string &username, const std::option
   }
 }
 
-bool AuthQueryHandler::DropUser(const std::string &username) {
-  if (!std::regex_match(username, name_regex_)) {
-    throw memgraph::query::QueryRuntimeException("Invalid user name.");
-  }
+bool AuthQueryHandler::DropUser(const std::string &username, system::Transaction *system_tx) {
   try {
     auto locked_auth = auth_->Lock();
     auto user = locked_auth->GetUser(username);
     if (!user) return false;
-    return locked_auth->RemoveUser(username);
+    return locked_auth->RemoveUser(username, system_tx);
   } catch (const memgraph::auth::AuthException &e) {
     throw memgraph::query::QueryRuntimeException(e.what());
   }
 }
 
-void AuthQueryHandler::SetPassword(const std::string &username, const std::optional<std::string> &password) {
-  if (!std::regex_match(username, name_regex_)) {
-    throw memgraph::query::QueryRuntimeException("Invalid user name.");
-  }
+void AuthQueryHandler::SetPassword(const std::string &username, const std::optional<std::string> &password,
+                                   system::Transaction *system_tx) {
   try {
     auto locked_auth = auth_->Lock();
     auto user = locked_auth->GetUser(username);
     if (!user) {
       throw memgraph::query::QueryRuntimeException("User '{}' doesn't exist.", username);
     }
-    user->UpdatePassword(password);
-    locked_auth->SaveUser(*user);
+    locked_auth->UpdatePassword(*user, password);
+    locked_auth->SaveUser(*user, system_tx);
   } catch (const memgraph::auth::AuthException &e) {
     throw memgraph::query::QueryRuntimeException(e.what());
   }
 }
 
-bool AuthQueryHandler::CreateRole(const std::string &rolename) {
-  if (!std::regex_match(rolename, name_regex_)) {
-    throw memgraph::query::QueryRuntimeException("Invalid role name.");
-  }
+bool AuthQueryHandler::CreateRole(const std::string &rolename, system::Transaction *system_tx) {
   try {
     auto locked_auth = auth_->Lock();
-    return locked_auth->AddRole(rolename).has_value();
+    return locked_auth->AddRole(rolename, system_tx).has_value();
   } catch (const memgraph::auth::AuthException &e) {
     throw memgraph::query::QueryRuntimeException(e.what());
   }
 }
 
 #ifdef MG_ENTERPRISE
-bool AuthQueryHandler::RevokeDatabaseFromUser(const std::string &db, const std::string &username) {
-  if (!std::regex_match(username, name_regex_)) {
-    throw memgraph::query::QueryRuntimeException("Invalid user name.");
-  }
+bool AuthQueryHandler::RevokeDatabaseFromUser(const std::string &db_name, const std::string &username,
+                                              system::Transaction *system_tx) {
   try {
     auto locked_auth = auth_->Lock();
     auto user = locked_auth->GetUser(username);
     if (!user) return false;
-    return locked_auth->RevokeDatabaseFromUser(db, username);
+    return locked_auth->RevokeDatabaseFromUser(db_name, username, system_tx);
   } catch (const memgraph::auth::AuthException &e) {
     throw memgraph::query::QueryRuntimeException(e.what());
   }
 }
 
-bool AuthQueryHandler::GrantDatabaseToUser(const std::string &db, const std::string &username) {
-  if (!std::regex_match(username, name_regex_)) {
-    throw memgraph::query::QueryRuntimeException("Invalid user name.");
-  }
+bool AuthQueryHandler::GrantDatabaseToUser(const std::string &db_name, const std::string &username,
+                                           system::Transaction *system_tx) {
   try {
     auto locked_auth = auth_->Lock();
     auto user = locked_auth->GetUser(username);
     if (!user) return false;
-    return locked_auth->GrantDatabaseToUser(db, username);
+    return locked_auth->GrantDatabaseToUser(db_name, username, system_tx);
   } catch (const memgraph::auth::AuthException &e) {
     throw memgraph::query::QueryRuntimeException(e.what());
   }
@@ -378,9 +360,6 @@ bool AuthQueryHandler::GrantDatabaseToUser(const std::string &db, const std::str
 
 std::vector<std::vector<memgraph::query::TypedValue>> AuthQueryHandler::GetDatabasePrivileges(
     const std::string &username) {
-  if (!std::regex_match(username, name_regex_)) {
-    throw memgraph::query::QueryRuntimeException("Invalid user or role name.");
-  }
   try {
     auto locked_auth = auth_->ReadLock();
     auto user = locked_auth->GetUser(username);
@@ -393,33 +372,28 @@ std::vector<std::vector<memgraph::query::TypedValue>> AuthQueryHandler::GetDatab
   }
 }
 
-bool AuthQueryHandler::SetMainDatabase(std::string_view db, const std::string &username) {
-  if (!std::regex_match(username, name_regex_)) {
-    throw memgraph::query::QueryRuntimeException("Invalid user name.");
-  }
+bool AuthQueryHandler::SetMainDatabase(std::string_view db_name, const std::string &username,
+                                       system::Transaction *system_tx) {
   try {
     auto locked_auth = auth_->Lock();
     auto user = locked_auth->GetUser(username);
     if (!user) return false;
-    return locked_auth->SetMainDatabase(db, username);
+    return locked_auth->SetMainDatabase(db_name, username, system_tx);
   } catch (const memgraph::auth::AuthException &e) {
     throw memgraph::query::QueryRuntimeException(e.what());
   }
 }
 
-void AuthQueryHandler::DeleteDatabase(std::string_view db) {
+void AuthQueryHandler::DeleteDatabase(std::string_view db_name, system::Transaction *system_tx) {
   try {
-    auth_->Lock()->DeleteDatabase(std::string(db));
+    auth_->Lock()->DeleteDatabase(std::string(db_name), system_tx);
   } catch (const memgraph::auth::AuthException &e) {
     throw memgraph::query::QueryRuntimeException(e.what());
   }
 }
 #endif
 
-bool AuthQueryHandler::DropRole(const std::string &rolename) {
-  if (!std::regex_match(rolename, name_regex_)) {
-    throw memgraph::query::QueryRuntimeException("Invalid role name.");
-  }
+bool AuthQueryHandler::DropRole(const std::string &rolename, system::Transaction *system_tx) {
   try {
     auto locked_auth = auth_->Lock();
     auto role = locked_auth->GetRole(rolename);
@@ -428,7 +402,7 @@ bool AuthQueryHandler::DropRole(const std::string &rolename) {
       return false;
     };
 
-    return locked_auth->RemoveRole(rolename);
+    return locked_auth->RemoveRole(rolename, system_tx);
   } catch (const memgraph::auth::AuthException &e) {
     throw memgraph::query::QueryRuntimeException(e.what());
   }
@@ -465,9 +439,6 @@ std::vector<memgraph::query::TypedValue> AuthQueryHandler::GetRolenames() {
 }
 
 std::optional<std::string> AuthQueryHandler::GetRolenameForUser(const std::string &username) {
-  if (!std::regex_match(username, name_regex_)) {
-    throw memgraph::query::QueryRuntimeException("Invalid user name.");
-  }
   try {
     auto locked_auth = auth_->ReadLock();
     auto user = locked_auth->GetUser(username);
@@ -485,9 +456,6 @@ std::optional<std::string> AuthQueryHandler::GetRolenameForUser(const std::strin
 }
 
 std::vector<memgraph::query::TypedValue> AuthQueryHandler::GetUsernamesForRole(const std::string &rolename) {
-  if (!std::regex_match(rolename, name_regex_)) {
-    throw memgraph::query::QueryRuntimeException("Invalid role name.");
-  }
   try {
     auto locked_auth = auth_->ReadLock();
     auto role = locked_auth->GetRole(rolename);
@@ -506,13 +474,8 @@ std::vector<memgraph::query::TypedValue> AuthQueryHandler::GetUsernamesForRole(c
   }
 }
 
-void AuthQueryHandler::SetRole(const std::string &username, const std::string &rolename) {
-  if (!std::regex_match(username, name_regex_)) {
-    throw memgraph::query::QueryRuntimeException("Invalid user name.");
-  }
-  if (!std::regex_match(rolename, name_regex_)) {
-    throw memgraph::query::QueryRuntimeException("Invalid role name.");
-  }
+void AuthQueryHandler::SetRole(const std::string &username, const std::string &rolename,
+                               system::Transaction *system_tx) {
   try {
     auto locked_auth = auth_->Lock();
     auto user = locked_auth->GetUser(username);
@@ -528,16 +491,13 @@ void AuthQueryHandler::SetRole(const std::string &username, const std::string &r
                                                    current_role->rolename());
     }
     user->SetRole(*role);
-    locked_auth->SaveUser(*user);
+    locked_auth->SaveUser(*user, system_tx);
   } catch (const memgraph::auth::AuthException &e) {
     throw memgraph::query::QueryRuntimeException(e.what());
   }
 }
 
-void AuthQueryHandler::ClearRole(const std::string &username) {
-  if (!std::regex_match(username, name_regex_)) {
-    throw memgraph::query::QueryRuntimeException("Invalid user name.");
-  }
+void AuthQueryHandler::ClearRole(const std::string &username, system::Transaction *system_tx) {
   try {
     auto locked_auth = auth_->Lock();
     auto user = locked_auth->GetUser(username);
@@ -545,16 +505,13 @@ void AuthQueryHandler::ClearRole(const std::string &username) {
       throw memgraph::query::QueryRuntimeException("User '{}' doesn't exist .", username);
     }
     user->ClearRole();
-    locked_auth->SaveUser(*user);
+    locked_auth->SaveUser(*user, system_tx);
   } catch (const memgraph::auth::AuthException &e) {
     throw memgraph::query::QueryRuntimeException(e.what());
   }
 }
 
 std::vector<std::vector<memgraph::query::TypedValue>> AuthQueryHandler::GetPrivileges(const std::string &user_or_role) {
-  if (!std::regex_match(user_or_role, name_regex_)) {
-    throw memgraph::query::QueryRuntimeException("Invalid user or role name.");
-  }
   try {
     auto locked_auth = auth_->ReadLock();
     std::vector<std::vector<memgraph::query::TypedValue>> grants;
@@ -602,7 +559,8 @@ void AuthQueryHandler::GrantPrivilege(
     const std::vector<std::unordered_map<memgraph::query::AuthQuery::FineGrainedPrivilege, std::vector<std::string>>>
         &edge_type_privileges
 #endif
-) {
+    ,
+    system::Transaction *system_tx) {
   EditPermissions(
       user_or_role, privileges,
 #ifdef MG_ENTERPRISE
@@ -625,11 +583,13 @@ void AuthQueryHandler::GrantPrivilege(
         }
       }
 #endif
-  );
+      ,
+      system_tx);
 }  // namespace memgraph::glue
 
 void AuthQueryHandler::DenyPrivilege(const std::string &user_or_role,
-                                     const std::vector<memgraph::query::AuthQuery::Privilege> &privileges) {
+                                     const std::vector<memgraph::query::AuthQuery::Privilege> &privileges,
+                                     system::Transaction *system_tx) {
   EditPermissions(
       user_or_role, privileges,
 #ifdef MG_ENTERPRISE
@@ -645,7 +605,8 @@ void AuthQueryHandler::DenyPrivilege(const std::string &user_or_role,
       ,
       [](auto &fine_grained_permissions, const auto &privilege_collection) {}
 #endif
-  );
+      ,
+      system_tx);
 }
 
 void AuthQueryHandler::RevokePrivilege(
@@ -657,7 +618,8 @@ void AuthQueryHandler::RevokePrivilege(
     const std::vector<std::unordered_map<memgraph::query::AuthQuery::FineGrainedPrivilege, std::vector<std::string>>>
         &edge_type_privileges
 #endif
-) {
+    ,
+    system::Transaction *system_tx) {
   EditPermissions(
       user_or_role, privileges,
 #ifdef MG_ENTERPRISE
@@ -679,7 +641,8 @@ void AuthQueryHandler::RevokePrivilege(
         }
       }
 #endif
-  );
+      ,
+      system_tx);
 }  // namespace memgraph::glue
 
 template <class TEditPermissionsFun
@@ -703,10 +666,8 @@ void AuthQueryHandler::EditPermissions(
     ,
     const TEditFineGrainedPermissionsFun &edit_fine_grained_permissions_fun
 #endif
-) {
-  if (!std::regex_match(user_or_role, name_regex_)) {
-    throw memgraph::query::QueryRuntimeException("Invalid user or role name.");
-  }
+    ,
+    system::Transaction *system_tx) {
   try {
     std::vector<memgraph::auth::Permission> permissions;
     permissions.reserve(privileges.size());
@@ -735,7 +696,7 @@ void AuthQueryHandler::EditPermissions(
         }
       }
 #endif
-      locked_auth->SaveUser(*user);
+      locked_auth->SaveUser(*user, system_tx);
     } else {
       for (const auto &permission : permissions) {
         edit_permissions_fun(role->permissions(), permission);
@@ -751,7 +712,7 @@ void AuthQueryHandler::EditPermissions(
         }
       }
 #endif
-      locked_auth->SaveRole(*role);
+      locked_auth->SaveRole(*role, system_tx);
     }
   } catch (const memgraph::auth::AuthException &e) {
     throw memgraph::query::QueryRuntimeException(e.what());

src/glue/auth_handler.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -23,35 +23,36 @@
 namespace memgraph::glue {
 
 class AuthQueryHandler final : public memgraph::query::AuthQueryHandler {
-  memgraph::utils::Synchronized<memgraph::auth::Auth, memgraph::utils::WritePrioritizedRWLock> *auth_;
-  std::string name_regex_string_;
-  std::regex name_regex_;
+  memgraph::auth::SynchedAuth *auth_;
 
  public:
-  AuthQueryHandler(memgraph::utils::Synchronized<memgraph::auth::Auth, memgraph::utils::WritePrioritizedRWLock> *auth,
-                   std::string name_regex_string);
+  explicit AuthQueryHandler(memgraph::auth::SynchedAuth *auth);
 
-  bool CreateUser(const std::string &username, const std::optional<std::string> &password) override;
+  bool CreateUser(const std::string &username, const std::optional<std::string> &password,
+                  system::Transaction *system_tx) override;
 
-  bool DropUser(const std::string &username) override;
+  bool DropUser(const std::string &username, system::Transaction *system_tx) override;
 
-  void SetPassword(const std::string &username, const std::optional<std::string> &password) override;
+  void SetPassword(const std::string &username, const std::optional<std::string> &password,
+                   system::Transaction *system_tx) override;
 
 #ifdef MG_ENTERPRISE
-  bool RevokeDatabaseFromUser(const std::string &db, const std::string &username) override;
+  bool RevokeDatabaseFromUser(const std::string &db_name, const std::string &username,
+                              system::Transaction *system_tx) override;
 
-  bool GrantDatabaseToUser(const std::string &db, const std::string &username) override;
+  bool GrantDatabaseToUser(const std::string &db_name, const std::string &username,
+                           system::Transaction *system_tx) override;
 
   std::vector<std::vector<memgraph::query::TypedValue>> GetDatabasePrivileges(const std::string &username) override;
 
-  bool SetMainDatabase(std::string_view db, const std::string &username) override;
+  bool SetMainDatabase(std::string_view db_name, const std::string &username, system::Transaction *system_tx) override;
 
-  void DeleteDatabase(std::string_view db) override;
+  void DeleteDatabase(std::string_view db_name, system::Transaction *system_tx) override;
 #endif
 
-  bool CreateRole(const std::string &rolename) override;
+  bool CreateRole(const std::string &rolename, system::Transaction *system_tx) override;
 
-  bool DropRole(const std::string &rolename) override;
+  bool DropRole(const std::string &rolename, system::Transaction *system_tx) override;
 
   std::vector<memgraph::query::TypedValue> GetUsernames() override;
 
@@ -61,9 +62,9 @@ class AuthQueryHandler final : public memgraph::query::AuthQueryHandler {
 
   std::vector<memgraph::query::TypedValue> GetUsernamesForRole(const std::string &rolename) override;
 
-  void SetRole(const std::string &username, const std::string &rolename) override;
+  void SetRole(const std::string &username, const std::string &rolename, system::Transaction *system_tx) override;
 
-  void ClearRole(const std::string &username) override;
+  void ClearRole(const std::string &username, system::Transaction *system_tx) override;
 
   std::vector<std::vector<memgraph::query::TypedValue>> GetPrivileges(const std::string &user_or_role) override;
 
@@ -77,10 +78,12 @@ class AuthQueryHandler final : public memgraph::query::AuthQueryHandler {
       const std::vector<std::unordered_map<memgraph::query::AuthQuery::FineGrainedPrivilege, std::vector<std::string>>>
           &edge_type_privileges
 #endif
-      ) override;
+      ,
+      system::Transaction *system_tx) override;
 
   void DenyPrivilege(const std::string &user_or_role,
-                     const std::vector<memgraph::query::AuthQuery::Privilege> &privileges) override;
+                     const std::vector<memgraph::query::AuthQuery::Privilege> &privileges,
+                     system::Transaction *system_tx) override;
 
   void RevokePrivilege(
       const std::string &user_or_role, const std::vector<memgraph::query::AuthQuery::Privilege> &privileges
@@ -91,7 +94,8 @@ class AuthQueryHandler final : public memgraph::query::AuthQueryHandler {
       const std::vector<std::unordered_map<memgraph::query::AuthQuery::FineGrainedPrivilege, std::vector<std::string>>>
           &edge_type_privileges
 #endif
-      ) override;
+      ,
+      system::Transaction *system_tx) override;
 
  private:
   template <class TEditPermissionsFun
@@ -115,6 +119,7 @@ class AuthQueryHandler final : public memgraph::query::AuthQueryHandler {
       ,
       const TEditFineGrainedPermissionsFun &edit_fine_grained_permissions_fun
 #endif
-  );
+      ,
+      system::Transaction *system_tx);
 };
 }  // namespace memgraph::glue

src/io/CMakeLists.txt

@@ -8,4 +8,5 @@ find_package(fmt REQUIRED)
 find_package(Threads REQUIRED)
 
 add_library(mg-io STATIC ${io_src_files})
+add_library(mg::io ALIAS mg-io)
 target_link_libraries(mg-io stdc++fs Threads::Threads fmt::fmt mg-utils)

src/io/network/endpoint.cpp

@@ -166,7 +166,7 @@ bool Endpoint::IsResolvableAddress(const std::string &address, uint16_t port) {
 }
 
 std::optional<std::pair<std::string, uint16_t>> Endpoint::ParseSocketOrAddress(
-    const std::string &address, const std::optional<uint16_t> default_port = {}) {
+    const std::string &address, const std::optional<uint16_t> default_port) {
   const std::string delimiter = ":";
   std::vector<std::string> parts = utils::Split(address, delimiter);
   if (parts.size() == 1) {

src/kvstore/kvstore.cpp

@@ -37,6 +37,7 @@ KVStore::KVStore(std::filesystem::path storage) : pimpl_(std::make_unique<impl>(
 }
 
 KVStore::~KVStore() {
+  if (pimpl_ == nullptr) return;
   spdlog::debug("Destroying KVStore at {}", pimpl_->storage.string());
   const auto sync = pimpl_->db->SyncWAL();
   if (!sync.ok()) spdlog::error("KVStore sync failed!");

src/license/license.cpp

@@ -1,4 +1,4 @@
-// Copyright 2022 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -92,7 +92,7 @@ void RegisterLicenseSettings(LicenseChecker &license_checker, utils::Settings &s
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
 LicenseChecker global_license_checker;
 
-LicenseChecker::~LicenseChecker() { scheduler_.Stop(); }
+LicenseChecker::~LicenseChecker() { Finalize(); }
 
 std::pair<std::string, std::string> LicenseChecker::ExtractLicenseInfo(const utils::Settings &settings) const {
   if (license_info_override_) {

src/license/license.hpp

@@ -1,4 +1,4 @@
-// Copyright 2022 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -89,6 +89,8 @@ struct LicenseChecker {
 
   utils::Synchronized<std::optional<LicenseInfo>, utils::SpinLock> &GetLicenseInfo();
 
+  void Finalize() { scheduler_.Stop(); }
+
  private:
   std::pair<std::string, std::string> ExtractLicenseInfo(const utils::Settings &settings) const;
   void RevalidateLicense(const utils::Settings &settings);

src/memgraph.cpp

@@ -11,12 +11,14 @@
 
 #include <cstdint>
 #include "audit/log.hpp"
+#include "auth/auth.hpp"
 #include "communication/websocket/auth.hpp"
 #include "communication/websocket/server.hpp"
+#include "coordination/coordinator_handlers.hpp"
 #include "dbms/constants.hpp"
+#include "dbms/dbms_handler.hpp"
 #include "dbms/inmemory/replication_handlers.hpp"
 #include "flags/all.hpp"
-#include "flags/run_time_configurable.hpp"
 #include "glue/MonitoringServerT.hpp"
 #include "glue/ServerT.hpp"
 #include "glue/auth_checker.hpp"
@@ -25,14 +27,19 @@
 #include "helpers.hpp"
 #include "license/license_sender.hpp"
 #include "memory/global_memory_control.hpp"
+#include "query/auth_query_handler.hpp"
 #include "query/config.hpp"
 #include "query/discard_value_stream.hpp"
 #include "query/interpreter.hpp"
+#include "query/interpreter_context.hpp"
 #include "query/procedure/callable_alias_mapper.hpp"
 #include "query/procedure/module.hpp"
 #include "query/procedure/py_module.hpp"
+#include "replication_handler/replication_handler.hpp"
+#include "replication_handler/system_replication.hpp"
 #include "requests/requests.hpp"
 #include "storage/v2/durability/durability.hpp"
+#include "system/system.hpp"
 #include "telemetry/telemetry.hpp"
 #include "utils/signals.hpp"
 #include "utils/sysinfo/memory.hpp"
@@ -40,10 +47,6 @@
 #include "utils/terminate_handler.hpp"
 #include "version.hpp"
 
-#include "dbms/dbms_handler.hpp"
-#include "query/auth_query_handler.hpp"
-#include "query/interpreter_context.hpp"
-
 namespace {
 constexpr const char *kMgUser = "MEMGRAPH_USER";
 constexpr const char *kMgPassword = "MEMGRAPH_PASSWORD";
@@ -256,6 +259,8 @@ int main(int argc, char **argv) {
   // register all runtime settings
   memgraph::license::RegisterLicenseSettings(memgraph::license::global_license_checker,
                                              memgraph::utils::global_settings);
+  memgraph::utils::OnScopeExit global_license_finalizer([] { memgraph::license::global_license_checker.Finalize(); });
+
   memgraph::flags::run_time::Initialize();
 
   memgraph::license::global_license_checker.CheckEnvLicense();
@@ -355,44 +360,75 @@ int main(int argc, char **argv) {
       .stream_transaction_conflict_retries = FLAGS_stream_transaction_conflict_retries,
       .stream_transaction_retry_interval = std::chrono::milliseconds(FLAGS_stream_transaction_retry_interval)};
 
-  auto auth_glue =
-      [flag = FLAGS_auth_user_or_role_name_regex](
-          memgraph::utils::Synchronized<memgraph::auth::Auth, memgraph::utils::WritePrioritizedRWLock> *auth,
-          std::unique_ptr<memgraph::query::AuthQueryHandler> &ah, std::unique_ptr<memgraph::query::AuthChecker> &ac) {
-        // Glue high level auth implementations to the query side
-        ah = std::make_unique<memgraph::glue::AuthQueryHandler>(auth, flag);
-        ac = std::make_unique<memgraph::glue::AuthChecker>(auth);
-        // Handle users passed via arguments
-        auto *maybe_username = std::getenv(kMgUser);
-        auto *maybe_password = std::getenv(kMgPassword);
-        auto *maybe_pass_file = std::getenv(kMgPassfile);
-        if (maybe_username && maybe_password) {
-          ah->CreateUser(maybe_username, maybe_password);
-        } else if (maybe_pass_file) {
-          const auto [username, password] = LoadUsernameAndPassword(maybe_pass_file);
-          if (!username.empty() && !password.empty()) {
-            ah->CreateUser(username, password);
-          }
-        }
-      };
+  auto auth_glue = [](memgraph::auth::SynchedAuth *auth, std::unique_ptr<memgraph::query::AuthQueryHandler> &ah,
+                      std::unique_ptr<memgraph::query::AuthChecker> &ac) {
+    // Glue high level auth implementations to the query side
+    ah = std::make_unique<memgraph::glue::AuthQueryHandler>(auth);
+    ac = std::make_unique<memgraph::glue::AuthChecker>(auth);
+    // Handle users passed via arguments
+    auto *maybe_username = std::getenv(kMgUser);
+    auto *maybe_password = std::getenv(kMgPassword);
+    auto *maybe_pass_file = std::getenv(kMgPassfile);
+    if (maybe_username && maybe_password) {
+      ah->CreateUser(maybe_username, maybe_password, nullptr);
+    } else if (maybe_pass_file) {
+      const auto [username, password] = LoadUsernameAndPassword(maybe_pass_file);
+      if (!username.empty() && !password.empty()) {
+        ah->CreateUser(username, password, nullptr);
+      }
+    }
+  };
 
-  // WIP
-  memgraph::utils::Synchronized<memgraph::auth::Auth, memgraph::utils::WritePrioritizedRWLock> auth_{data_directory /
-                                                                                                     "auth"};
+  memgraph::auth::Auth::Config auth_config{FLAGS_auth_user_or_role_name_regex, FLAGS_auth_password_strength_regex,
+                                           FLAGS_auth_password_permit_null};
+  memgraph::auth::SynchedAuth auth_{data_directory / "auth", auth_config};
   std::unique_ptr<memgraph::query::AuthQueryHandler> auth_handler;
   std::unique_ptr<memgraph::query::AuthChecker> auth_checker;
   auth_glue(&auth_, auth_handler, auth_checker);
 
-  memgraph::dbms::DbmsHandler dbms_handler(db_config
+  auto system = memgraph::system::System{db_config.durability.storage_directory, FLAGS_data_recovery_on_startup};
+
+  // singleton replication state
+  memgraph::replication::ReplicationState repl_state{ReplicationStateRootPath(db_config)};
+
+  // singleton coordinator state
+#ifdef MG_ENTERPRISE
+  memgraph::coordination::CoordinatorState coordinator_state;
+#endif
+
+  memgraph::dbms::DbmsHandler dbms_handler(db_config, system, repl_state
 #ifdef MG_ENTERPRISE
                                            ,
-                                           &auth_, FLAGS_data_recovery_on_startup
+                                           auth_, FLAGS_data_recovery_on_startup
 #endif
   );
+
+  // Note: Now that all system's subsystems are initialised (dbms & auth)
+  //       We can now initialise the recovery of replication (which will include those subsystems)
+  //       ReplicationHandler will handle the recovery
+  auto replication_handler = memgraph::replication::ReplicationHandler{repl_state, dbms_handler
+#ifdef MG_ENTERPRISE
+                                                                       ,
+                                                                       &system, auth_
+#endif
+  };
+
+#ifdef MG_ENTERPRISE
+  // MAIN or REPLICA instance
+  if (FLAGS_coordinator_server_port) {
+    memgraph::dbms::CoordinatorHandlers::Register(coordinator_state.GetCoordinatorServer(), replication_handler);
+    MG_ASSERT(coordinator_state.GetCoordinatorServer().Start(), "Failed to start coordinator server!");
+  }
+#endif
+
   auto db_acc = dbms_handler.Get();
 
-  memgraph::query::InterpreterContext interpreter_context_(
-      interp_config, &dbms_handler, &dbms_handler.ReplicationState(), auth_handler.get(), auth_checker.get());
+  memgraph::query::InterpreterContext interpreter_context_(interp_config, &dbms_handler, &repl_state, system,
+#ifdef MG_ENTERPRISE
+                                                           &coordinator_state,
+#endif
+                                                           auth_handler.get(), auth_checker.get(),
+                                                           &replication_handler);
   MG_ASSERT(db_acc, "Failed to access the main database");
 
   memgraph::query::procedure::gModuleRegistry.SetModulesDirectory(memgraph::flags::ParseQueryModulesDirectory(),
@@ -459,9 +495,9 @@ int main(int argc, char **argv) {
   if (FLAGS_telemetry_enabled) {
     telemetry.emplace(telemetry_server, data_directory / "telemetry", memgraph::glue::run_id_, machine_id,
                       service_name == "BoltS", FLAGS_data_directory, std::chrono::minutes(10));
-    telemetry->AddStorageCollector(dbms_handler, auth_);
+    telemetry->AddStorageCollector(dbms_handler, auth_, repl_state);
 #ifdef MG_ENTERPRISE
-    telemetry->AddDatabaseCollector(dbms_handler);
+    telemetry->AddDatabaseCollector(dbms_handler, repl_state);
 #else
     telemetry->AddDatabaseCollector();
 #endif
@@ -546,6 +582,7 @@ int main(int argc, char **argv) {
 
   memgraph::query::procedure::gModuleRegistry.UnloadAllModules();
 
+  python_gc_scheduler.Stop();
   Py_END_ALLOW_THREADS;
   // Shutdown Python
   Py_Finalize();

src/mg_import_csv.cpp

@@ -32,7 +32,7 @@
 #include "utils/timer.hpp"
 #include "version.hpp"
 
-using memgraph::replication::ReplicationRole;
+using memgraph::replication_coordination_glue::ReplicationRole;
 
 bool ValidateControlCharacter(const char *flagname, const std::string &value) {
   if (value.empty()) {

src/query/CMakeLists.txt

@@ -56,6 +56,7 @@ target_link_libraries(mg-query PUBLIC dl
     mg-kvstore
     mg-memory
     mg::csv
+    mg::system
     mg-flags
     mg-dbms
     mg-events)

src/query/auth_query_handler.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -18,6 +18,7 @@
 
 #include "query/frontend/ast/ast.hpp"  // overkill
 #include "query/typed_value.hpp"
+#include "system/system.hpp"
 
 namespace memgraph::query {
 
@@ -33,23 +34,27 @@ class AuthQueryHandler {
 
   /// Return false if the user already exists.
   /// @throw QueryRuntimeException if an error ocurred.
-  virtual bool CreateUser(const std::string &username, const std::optional<std::string> &password) = 0;
+  virtual bool CreateUser(const std::string &username, const std::optional<std::string> &password,
+                          system::Transaction *system_tx) = 0;
 
   /// Return false if the user does not exist.
   /// @throw QueryRuntimeException if an error ocurred.
-  virtual bool DropUser(const std::string &username) = 0;
+  virtual bool DropUser(const std::string &username, system::Transaction *system_tx) = 0;
 
   /// @throw QueryRuntimeException if an error ocurred.
-  virtual void SetPassword(const std::string &username, const std::optional<std::string> &password) = 0;
+  virtual void SetPassword(const std::string &username, const std::optional<std::string> &password,
+                           system::Transaction *system_tx) = 0;
 
 #ifdef MG_ENTERPRISE
   /// Return true if access revoked successfully
   /// @throw QueryRuntimeException if an error ocurred.
-  virtual bool RevokeDatabaseFromUser(const std::string &db, const std::string &username) = 0;
+  virtual bool RevokeDatabaseFromUser(const std::string &db, const std::string &username,
+                                      system::Transaction *system_tx) = 0;
 
   /// Return true if access granted successfully
   /// @throw QueryRuntimeException if an error ocurred.
-  virtual bool GrantDatabaseToUser(const std::string &db, const std::string &username) = 0;
+  virtual bool GrantDatabaseToUser(const std::string &db, const std::string &username,
+                                   system::Transaction *system_tx) = 0;
 
   /// Returns database access rights for the user
   /// @throw QueryRuntimeException if an error ocurred.
@@ -57,20 +62,20 @@ class AuthQueryHandler {
 
   /// Return true if main database set successfully
   /// @throw QueryRuntimeException if an error ocurred.
-  virtual bool SetMainDatabase(std::string_view db, const std::string &username) = 0;
+  virtual bool SetMainDatabase(std::string_view db, const std::string &username, system::Transaction *system_tx) = 0;
 
   /// Delete database from all users
   /// @throw QueryRuntimeException if an error ocurred.
-  virtual void DeleteDatabase(std::string_view db) = 0;
+  virtual void DeleteDatabase(std::string_view db, system::Transaction *system_tx) = 0;
 #endif
 
   /// Return false if the role already exists.
   /// @throw QueryRuntimeException if an error ocurred.
-  virtual bool CreateRole(const std::string &rolename) = 0;
+  virtual bool CreateRole(const std::string &rolename, system::Transaction *system_tx) = 0;
 
   /// Return false if the role does not exist.
   /// @throw QueryRuntimeException if an error ocurred.
-  virtual bool DropRole(const std::string &rolename) = 0;
+  virtual bool DropRole(const std::string &rolename, system::Transaction *system_tx) = 0;
 
   /// @throw QueryRuntimeException if an error ocurred.
   virtual std::vector<memgraph::query::TypedValue> GetUsernames() = 0;
@@ -85,10 +90,10 @@ class AuthQueryHandler {
   virtual std::vector<memgraph::query::TypedValue> GetUsernamesForRole(const std::string &rolename) = 0;
 
   /// @throw QueryRuntimeException if an error ocurred.
-  virtual void SetRole(const std::string &username, const std::string &rolename) = 0;
+  virtual void SetRole(const std::string &username, const std::string &rolename, system::Transaction *system_tx) = 0;
 
   /// @throw QueryRuntimeException if an error ocurred.
-  virtual void ClearRole(const std::string &username) = 0;
+  virtual void ClearRole(const std::string &username, system::Transaction *system_tx) = 0;
 
   virtual std::vector<std::vector<memgraph::query::TypedValue>> GetPrivileges(const std::string &user_or_role) = 0;
 
@@ -103,11 +108,13 @@ class AuthQueryHandler {
       const std::vector<std::unordered_map<memgraph::query::AuthQuery::FineGrainedPrivilege, std::vector<std::string>>>
           &edge_type_privileges
 #endif
-      ) = 0;
+      ,
+      system::Transaction *system_tx) = 0;
 
   /// @throw QueryRuntimeException if an error ocurred.
   virtual void DenyPrivilege(const std::string &user_or_role,
-                             const std::vector<memgraph::query::AuthQuery::Privilege> &privileges) = 0;
+                             const std::vector<memgraph::query::AuthQuery::Privilege> &privileges,
+                             system::Transaction *system_tx) = 0;
 
   /// @throw QueryRuntimeException if an error ocurred.
   virtual void RevokePrivilege(
@@ -120,7 +127,8 @@ class AuthQueryHandler {
       const std::vector<std::unordered_map<memgraph::query::AuthQuery::FineGrainedPrivilege, std::vector<std::string>>>
           &edge_type_privileges
 #endif
-      ) = 0;
+      ,
+      system::Transaction *system_tx) = 0;
 };
 
 }  // namespace memgraph::query

src/query/common.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -72,8 +72,9 @@ class TypedValueVectorCompare final {
 
 /// Raise QueryRuntimeException if the value for symbol isn't of expected type.
 inline void ExpectType(const Symbol &symbol, const TypedValue &value, TypedValue::Type expected) {
-  if (value.type() != expected)
+  if (value.type() != expected) [[unlikely]] {
     throw QueryRuntimeException("Expected a {} for '{}', but got {}.", expected, symbol.name(), value.type());
+  }
 }
 
 inline void ProcessError(const storage::Error error) {

src/query/config.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source

src/query/exceptions.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -259,6 +259,13 @@ class ReplicationModificationInMulticommandTxException : public QueryException {
   SPECIALIZE_GET_EXCEPTION_NAME(ReplicationModificationInMulticommandTxException)
 };
 
+class CoordinatorModificationInMulticommandTxException : public QueryException {
+ public:
+  CoordinatorModificationInMulticommandTxException()
+      : QueryException("Coordinator clause not allowed in multicommand transactions.") {}
+  SPECIALIZE_GET_EXCEPTION_NAME(CoordinatorModificationInMulticommandTxException)
+};
+
 class ReplicationDisabledOnDiskStorage : public QueryException {
  public:
   ReplicationDisabledOnDiskStorage() : QueryException("Replication is not supported while in on-disk storage mode.") {}

src/query/frontend/ast/ast.cpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -239,6 +239,9 @@ constexpr utils::TypeInfo query::DumpQuery::kType{utils::TypeId::AST_DUMP_QUERY,
 constexpr utils::TypeInfo query::ReplicationQuery::kType{utils::TypeId::AST_REPLICATION_QUERY, "ReplicationQuery",
                                                          &query::Query::kType};
 
+constexpr utils::TypeInfo query::CoordinatorQuery::kType{utils::TypeId::AST_COORDINATOR_QUERY, "CoordinatorQuery",
+                                                         &query::Query::kType};
+
 constexpr utils::TypeInfo query::LockPathQuery::kType{utils::TypeId::AST_LOCK_PATH_QUERY, "LockPathQuery",
                                                       &query::Query::kType};
 

src/query/frontend/ast/ast.hpp

@@ -1209,7 +1209,8 @@ class PropertyLookup : public memgraph::query::Expression {
   }
 
  protected:
-  PropertyLookup(Expression *expression, PropertyIx property) : expression_(expression), property_(property) {}
+  PropertyLookup(Expression *expression, PropertyIx property)
+      : expression_(expression), property_(std::move(property)) {}
 
  private:
   friend class AstStorage;
@@ -1805,9 +1806,9 @@ class EdgeAtom : public memgraph::query::PatternAtom {
   static const utils::TypeInfo kType;
   const utils::TypeInfo &GetTypeInfo() const override { return kType; }
 
-  enum class Type { SINGLE, DEPTH_FIRST, BREADTH_FIRST, WEIGHTED_SHORTEST_PATH, ALL_SHORTEST_PATHS };
+  enum class Type : uint8_t { SINGLE, DEPTH_FIRST, BREADTH_FIRST, WEIGHTED_SHORTEST_PATH, ALL_SHORTEST_PATHS };
 
-  enum class Direction { IN, OUT, BOTH };
+  enum class Direction : uint8_t { IN, OUT, BOTH };
 
   /// Lambda for use in filtering or weight calculation during variable expand.
   struct Lambda {
@@ -2216,7 +2217,7 @@ class IndexQuery : public memgraph::query::Query {
 
  protected:
   IndexQuery(Action action, LabelIx label, std::vector<PropertyIx> properties)
-      : action_(action), label_(label), properties_(properties) {}
+      : action_(action), label_(std::move(label)), properties_(std::move(properties)) {}
 
  private:
   friend class AstStorage;
@@ -2849,6 +2850,7 @@ class AuthQuery : public memgraph::query::Query {
     TRANSACTION_MANAGEMENT,
     MULTI_DATABASE_EDIT,
     MULTI_DATABASE_USE,
+    COORDINATOR
   };
 
   enum class FineGrainedPrivilege { NOTHING, READ, UPDATE, CREATE_DELETE };
@@ -2927,7 +2929,8 @@ const std::vector<AuthQuery::Privilege> kPrivilegesAll = {AuthQuery::Privilege::
                                                           AuthQuery::Privilege::TRANSACTION_MANAGEMENT,
                                                           AuthQuery::Privilege::STORAGE_MODE,
                                                           AuthQuery::Privilege::MULTI_DATABASE_EDIT,
-                                                          AuthQuery::Privilege::MULTI_DATABASE_USE};
+                                                          AuthQuery::Privilege::MULTI_DATABASE_USE,
+                                                          AuthQuery::Privilege::COORDINATOR};
 
 class DatabaseInfoQuery : public memgraph::query::Query {
  public:
@@ -3039,8 +3042,9 @@ class ReplicationQuery : public memgraph::query::Query {
 
   memgraph::query::ReplicationQuery::Action action_;
   memgraph::query::ReplicationQuery::ReplicationRole role_;
-  std::string replica_name_;
+  std::string instance_name_;
   memgraph::query::Expression *socket_address_{nullptr};
+  memgraph::query::Expression *coordinator_socket_address_{nullptr};
   memgraph::query::Expression *port_{nullptr};
   memgraph::query::ReplicationQuery::SyncMode sync_mode_;
 
@@ -3048,10 +3052,53 @@ class ReplicationQuery : public memgraph::query::Query {
     ReplicationQuery *object = storage->Create<ReplicationQuery>();
     object->action_ = action_;
     object->role_ = role_;
-    object->replica_name_ = replica_name_;
+    object->instance_name_ = instance_name_;
     object->socket_address_ = socket_address_ ? socket_address_->Clone(storage) : nullptr;
     object->port_ = port_ ? port_->Clone(storage) : nullptr;
     object->sync_mode_ = sync_mode_;
+    object->coordinator_socket_address_ =
+        coordinator_socket_address_ ? coordinator_socket_address_->Clone(storage) : nullptr;
+
+    return object;
+  }
+
+ private:
+  friend class AstStorage;
+};
+
+class CoordinatorQuery : public memgraph::query::Query {
+ public:
+  static const utils::TypeInfo kType;
+  const utils::TypeInfo &GetTypeInfo() const override { return kType; }
+
+  enum class Action {
+    REGISTER_INSTANCE,
+    SET_INSTANCE_TO_MAIN,
+    SHOW_REPLICATION_CLUSTER,
+  };
+
+  enum class SyncMode { SYNC, ASYNC };
+
+  CoordinatorQuery() = default;
+
+  DEFVISITABLE(QueryVisitor<void>);
+
+  memgraph::query::CoordinatorQuery::Action action_;
+  std::string instance_name_;
+  memgraph::query::Expression *replication_socket_address_{nullptr};
+  memgraph::query::Expression *coordinator_socket_address_{nullptr};
+  memgraph::query::CoordinatorQuery::SyncMode sync_mode_;
+
+  CoordinatorQuery *Clone(AstStorage *storage) const override {
+    auto *object = storage->Create<CoordinatorQuery>();
+    object->action_ = action_;
+    object->instance_name_ = instance_name_;
+    object->replication_socket_address_ =
+        replication_socket_address_ ? replication_socket_address_->Clone(storage) : nullptr;
+    object->sync_mode_ = sync_mode_;
+    object->coordinator_socket_address_ =
+        coordinator_socket_address_ ? coordinator_socket_address_->Clone(storage) : nullptr;
+
     return object;
   }
 

src/query/frontend/ast/ast_visitor.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -108,6 +108,7 @@ class MultiDatabaseQuery;
 class ShowDatabasesQuery;
 class EdgeImportModeQuery;
 class PatternComprehension;
+class CoordinatorQuery;
 
 using TreeCompositeVisitor = utils::CompositeVisitor<
     SingleQuery, CypherUnion, NamedExpression, OrOperator, XorOperator, AndOperator, NotOperator, AdditionOperator,
@@ -146,6 +147,7 @@ class QueryVisitor
                             SystemInfoQuery, ConstraintQuery, DumpQuery, ReplicationQuery, LockPathQuery,
                             FreeMemoryQuery, TriggerQuery, IsolationLevelQuery, CreateSnapshotQuery, StreamQuery,
                             SettingQuery, VersionQuery, ShowConfigQuery, TransactionQueueQuery, StorageModeQuery,
-                            AnalyzeGraphQuery, MultiDatabaseQuery, ShowDatabasesQuery, EdgeImportModeQuery> {};
+                            AnalyzeGraphQuery, MultiDatabaseQuery, ShowDatabasesQuery, EdgeImportModeQuery,
+                            CoordinatorQuery> {};
 
 }  // namespace memgraph::query

src/query/frontend/ast/cypher_main_visitor.cpp

@@ -302,6 +302,13 @@ antlrcpp::Any CypherMainVisitor::visitReplicationQuery(MemgraphCypher::Replicati
   return replication_query;
 }
 
+antlrcpp::Any CypherMainVisitor::visitCoordinatorQuery(MemgraphCypher::CoordinatorQueryContext *ctx) {
+  MG_ASSERT(ctx->children.size() == 1, "CoordinatorQuery should have exactly one child!");
+  auto *coordinator_query = std::any_cast<CoordinatorQuery *>(ctx->children[0]->accept(this));
+  query_ = coordinator_query;
+  return coordinator_query;
+}
+
 antlrcpp::Any CypherMainVisitor::visitEdgeImportModeQuery(MemgraphCypher::EdgeImportModeQueryContext *ctx) {
   auto *edge_import_mode_query = storage_->Create<EdgeImportModeQuery>();
   if (ctx->ACTIVE()) {
@@ -316,24 +323,34 @@ antlrcpp::Any CypherMainVisitor::visitEdgeImportModeQuery(MemgraphCypher::EdgeIm
 antlrcpp::Any CypherMainVisitor::visitSetReplicationRole(MemgraphCypher::SetReplicationRoleContext *ctx) {
   auto *replication_query = storage_->Create<ReplicationQuery>();
   replication_query->action_ = ReplicationQuery::Action::SET_REPLICATION_ROLE;
+
+  auto set_replication_port = [replication_query, ctx, this]() -> void {
+    if (ctx->port->numberLiteral() && ctx->port->numberLiteral()->integerLiteral()) {
+      replication_query->port_ = std::any_cast<Expression *>(ctx->port->accept(this));
+    } else {
+      throw SyntaxException("Port must be an integer literal!");
+    }
+  };
+
   if (ctx->MAIN()) {
+    replication_query->role_ = ReplicationQuery::ReplicationRole::MAIN;
     if (ctx->WITH() || ctx->PORT()) {
       throw SemanticException("Main can't set a port!");
     }
-    replication_query->role_ = ReplicationQuery::ReplicationRole::MAIN;
+
   } else if (ctx->REPLICA()) {
     replication_query->role_ = ReplicationQuery::ReplicationRole::REPLICA;
     if (ctx->WITH() && ctx->PORT()) {
-      if (ctx->port->numberLiteral() && ctx->port->numberLiteral()->integerLiteral()) {
-        replication_query->port_ = std::any_cast<Expression *>(ctx->port->accept(this));
-      } else {
-        throw SyntaxException("Port must be an integer literal!");
-      }
+      set_replication_port();
+    } else {
+      throw SemanticException("Replica must set a port!");
     }
   }
+
   return replication_query;
 }
-antlrcpp::Any CypherMainVisitor::visitShowReplicationRole(MemgraphCypher::ShowReplicationRoleContext *ctx) {
+
+antlrcpp::Any CypherMainVisitor::visitShowReplicationRole(MemgraphCypher::ShowReplicationRoleContext * /*ctx*/) {
   auto *replication_query = storage_->Create<ReplicationQuery>();
   replication_query->action_ = ReplicationQuery::Action::SHOW_REPLICATION_ROLE;
   return replication_query;
@@ -342,7 +359,7 @@ antlrcpp::Any CypherMainVisitor::visitShowReplicationRole(MemgraphCypher::ShowRe
 antlrcpp::Any CypherMainVisitor::visitRegisterReplica(MemgraphCypher::RegisterReplicaContext *ctx) {
   auto *replication_query = storage_->Create<ReplicationQuery>();
   replication_query->action_ = ReplicationQuery::Action::REGISTER_REPLICA;
-  replication_query->replica_name_ = std::any_cast<std::string>(ctx->replicaName()->symbolicName()->accept(this));
+  replication_query->instance_name_ = std::any_cast<std::string>(ctx->instanceName()->symbolicName()->accept(this));
   if (ctx->SYNC()) {
     replication_query->sync_mode_ = memgraph::query::ReplicationQuery::SyncMode::SYNC;
   } else if (ctx->ASYNC()) {
@@ -351,26 +368,67 @@ antlrcpp::Any CypherMainVisitor::visitRegisterReplica(MemgraphCypher::RegisterRe
 
   if (!ctx->socketAddress()->literal()->StringLiteral()) {
     throw SemanticException("Socket address should be a string literal!");
-  } else {
-    replication_query->socket_address_ = std::any_cast<Expression *>(ctx->socketAddress()->accept(this));
   }
+  replication_query->socket_address_ = std::any_cast<Expression *>(ctx->socketAddress()->accept(this));
 
   return replication_query;
 }
 
+// License check is done in the interpreter.
+antlrcpp::Any CypherMainVisitor::visitRegisterInstanceOnCoordinator(
+    MemgraphCypher::RegisterInstanceOnCoordinatorContext *ctx) {
+  auto *coordinator_query = storage_->Create<CoordinatorQuery>();
+  if (!ctx->replicationSocketAddress()->literal()->StringLiteral()) {
+    throw SemanticException("Replication socket address should be a string literal!");
+  }
+
+  if (!ctx->coordinatorSocketAddress()->literal()->StringLiteral()) {
+    throw SemanticException("Coordinator socket address should be a string literal!");
+  }
+  coordinator_query->action_ = CoordinatorQuery::Action::REGISTER_INSTANCE;
+  coordinator_query->replication_socket_address_ =
+      std::any_cast<Expression *>(ctx->replicationSocketAddress()->accept(this));
+  coordinator_query->coordinator_socket_address_ =
+      std::any_cast<Expression *>(ctx->coordinatorSocketAddress()->accept(this));
+  coordinator_query->instance_name_ = std::any_cast<std::string>(ctx->instanceName()->symbolicName()->accept(this));
+  if (ctx->ASYNC()) {
+    coordinator_query->sync_mode_ = memgraph::query::CoordinatorQuery::SyncMode::ASYNC;
+  } else {
+    coordinator_query->sync_mode_ = memgraph::query::CoordinatorQuery::SyncMode::SYNC;
+  }
+
+  return coordinator_query;
+}
+
+// License check is done in the interpreter
+antlrcpp::Any CypherMainVisitor::visitShowReplicationCluster(MemgraphCypher::ShowReplicationClusterContext * /*ctx*/) {
+  auto *coordinator_query = storage_->Create<CoordinatorQuery>();
+  coordinator_query->action_ = CoordinatorQuery::Action::SHOW_REPLICATION_CLUSTER;
+  return coordinator_query;
+}
+
 antlrcpp::Any CypherMainVisitor::visitDropReplica(MemgraphCypher::DropReplicaContext *ctx) {
   auto *replication_query = storage_->Create<ReplicationQuery>();
   replication_query->action_ = ReplicationQuery::Action::DROP_REPLICA;
-  replication_query->replica_name_ = std::any_cast<std::string>(ctx->replicaName()->symbolicName()->accept(this));
+  replication_query->instance_name_ = std::any_cast<std::string>(ctx->instanceName()->symbolicName()->accept(this));
   return replication_query;
 }
 
-antlrcpp::Any CypherMainVisitor::visitShowReplicas(MemgraphCypher::ShowReplicasContext *ctx) {
+antlrcpp::Any CypherMainVisitor::visitShowReplicas(MemgraphCypher::ShowReplicasContext * /*ctx*/) {
   auto *replication_query = storage_->Create<ReplicationQuery>();
   replication_query->action_ = ReplicationQuery::Action::SHOW_REPLICAS;
   return replication_query;
 }
 
+// License check is done in the interpreter
+antlrcpp::Any CypherMainVisitor::visitSetInstanceToMain(MemgraphCypher::SetInstanceToMainContext *ctx) {
+  auto *coordinator_query = storage_->Create<CoordinatorQuery>();
+  coordinator_query->action_ = CoordinatorQuery::Action::SET_INSTANCE_TO_MAIN;
+  coordinator_query->instance_name_ = std::any_cast<std::string>(ctx->instanceName()->symbolicName()->accept(this));
+  query_ = coordinator_query;
+  return coordinator_query;
+}
+
 antlrcpp::Any CypherMainVisitor::visitLockPathQuery(MemgraphCypher::LockPathQueryContext *ctx) {
   auto *lock_query = storage_->Create<LockPathQuery>();
   if (ctx->STATUS()) {
@@ -1638,6 +1696,7 @@ antlrcpp::Any CypherMainVisitor::visitPrivilege(MemgraphCypher::PrivilegeContext
   if (ctx->STORAGE_MODE()) return AuthQuery::Privilege::STORAGE_MODE;
   if (ctx->MULTI_DATABASE_EDIT()) return AuthQuery::Privilege::MULTI_DATABASE_EDIT;
   if (ctx->MULTI_DATABASE_USE()) return AuthQuery::Privilege::MULTI_DATABASE_USE;
+  if (ctx->COORDINATOR()) return AuthQuery::Privilege::COORDINATOR;
   LOG_FATAL("Should not get here - unknown privilege!");
 }
 
@@ -1752,7 +1811,11 @@ antlrcpp::Any CypherMainVisitor::visitReturnBody(MemgraphCypher::ReturnBodyConte
     body.skip = static_cast<Expression *>(std::any_cast<Expression *>(ctx->skip()->accept(this)));
   }
   if (ctx->limit()) {
-    body.limit = static_cast<Expression *>(std::any_cast<Expression *>(ctx->limit()->accept(this)));
+    if (ctx->limit()->expression()) {
+      body.limit = std::any_cast<Expression *>(ctx->limit()->accept(this));
+    } else {
+      body.limit = std::any_cast<ParameterLookup *>(ctx->limit()->accept(this));
+    }
   }
   std::tie(body.all_identifiers, body.named_expressions) =
       std::any_cast<std::pair<bool, std::vector<NamedExpression *>>>(ctx->returnItems()->accept(this));