Files
memgraph/src/coordination/raft_state.cpp
2024-02-13 08:49:28 +00:00

141 lines
5.3 KiB
C++

// 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/raft_state.hpp"
#include "coordination/coordinator_exceptions.hpp"
#include "nuraft/coordinator_state_machine.hpp"
#include "nuraft/coordinator_state_manager.hpp"
#include "utils/counter.hpp"
namespace memgraph::coordination {
using nuraft::asio_service;
using nuraft::cb_func;
using nuraft::CbReturnCode;
using nuraft::cmd_result;
using nuraft::cs_new;
using nuraft::ptr;
using nuraft::raft_params;
using nuraft::raft_server;
using nuraft::srv_config;
using raft_result = cmd_result<ptr<buffer>>;
RaftState::RaftState(BecomeLeaderCb become_leader_cb, BecomeFollowerCb become_follower_cb, uint32_t raft_server_id,
uint32_t raft_port, std::string raft_address)
: raft_server_id_(raft_server_id),
raft_port_(raft_port),
raft_address_(std::move(raft_address)),
state_machine_(cs_new<CoordinatorStateMachine>()),
state_manager_(
cs_new<CoordinatorStateManager>(raft_server_id_, raft_address_ + ":" + std::to_string(raft_port_))),
logger_(nullptr),
become_leader_cb_(std::move(become_leader_cb)),
become_follower_cb_(std::move(become_follower_cb)) {}
auto RaftState::InitRaftServer() -> void {
asio_service::options asio_opts;
asio_opts.thread_pool_size_ = 1; // TODO: (andi) Improve this
raft_params params;
params.heart_beat_interval_ = 100;
params.election_timeout_lower_bound_ = 200;
params.election_timeout_upper_bound_ = 400;
// 5 logs are preserved before the last snapshot
params.reserved_log_items_ = 5;
// Create snapshot for every 5 log appends
params.snapshot_distance_ = 5;
params.client_req_timeout_ = 3000;
params.return_method_ = raft_params::blocking;
raft_server::init_options init_opts;
init_opts.raft_callback_ = [this](cb_func::Type event_type, cb_func::Param *param) -> nuraft::CbReturnCode {
if (event_type == cb_func::BecomeLeader) {
spdlog::info("Node {} became leader", param->leaderId);
become_leader_cb_();
} else if (event_type == cb_func::BecomeFollower) {
spdlog::info("Node {} became follower", param->myId);
become_follower_cb_();
}
return CbReturnCode::Ok;
};
raft_launcher launcher;
raft_server_ = launcher.init(state_machine_, state_manager_, logger_, static_cast<int>(raft_port_), asio_opts, params,
init_opts);
if (!raft_server_) {
throw RaftServerStartException("Failed to launch raft server on {}:{}", raft_address_, raft_port_);
}
auto maybe_stop = utils::ResettableCounter<20>();
do {
if (raft_server_->is_initialized()) {
return;
}
std::this_thread::sleep_for(std::chrono::milliseconds(250));
} while (!maybe_stop());
throw RaftServerStartException("Failed to initialize raft server on {}:{}", raft_address_, raft_port_);
}
auto RaftState::MakeRaftState(BecomeLeaderCb become_leader_cb, BecomeFollowerCb become_follower_cb) -> RaftState {
uint32_t raft_server_id{0};
uint32_t raft_port{0};
try {
raft_server_id = FLAGS_raft_server_id;
raft_port = FLAGS_raft_server_port;
} catch (std::exception const &e) {
throw RaftCouldNotParseFlagsException("Failed to parse flags: {}", e.what());
}
auto raft_state =
RaftState(std::move(become_leader_cb), std::move(become_follower_cb), raft_server_id, raft_port, "127.0.0.1");
raft_state.InitRaftServer();
return raft_state;
}
RaftState::~RaftState() { launcher_.shutdown(); }
auto RaftState::InstanceName() const -> std::string { return "coordinator_" + std::to_string(raft_server_id_); }
auto RaftState::RaftSocketAddress() const -> std::string { return raft_address_ + ":" + std::to_string(raft_port_); }
auto RaftState::AddCoordinatorInstance(uint32_t raft_server_id, uint32_t raft_port, std::string raft_address) -> void {
auto const endpoint = raft_address + ":" + std::to_string(raft_port);
srv_config const srv_config_to_add(static_cast<int>(raft_server_id), endpoint);
if (!raft_server_->add_srv(srv_config_to_add)->get_accepted()) {
throw RaftAddServerException("Failed to add server {} to the cluster", endpoint);
}
spdlog::info("Request to add server {} to the cluster accepted", endpoint);
}
auto RaftState::GetAllCoordinators() const -> std::vector<ptr<srv_config>> {
std::vector<ptr<srv_config>> all_srv_configs;
raft_server_->get_srv_config_all(all_srv_configs);
return all_srv_configs;
}
auto RaftState::IsLeader() const -> bool { return raft_server_->is_leader(); }
auto RaftState::RequestLeadership() -> bool { return raft_server_->is_leader() || raft_server_->request_leadership(); }
auto RaftState::AppendRegisterReplicationInstance(std::string const &instance) -> ptr<raft_result> {
auto new_log = CoordinatorStateMachine::EncodeRegisterReplicationInstance(instance);
return raft_server_->append_entries({new_log});
}
} // namespace memgraph::coordination
#endif