diff --git a/sources/tech/20170712 How To Setup Apache Hadoop On CentOS.md b/sources/tech/20170712 How To Setup Apache Hadoop On CentOS.md new file mode 100644 index 0000000000..a61a4eb192 --- /dev/null +++ b/sources/tech/20170712 How To Setup Apache Hadoop On CentOS.md @@ -0,0 +1,261 @@ +How To Setup Apache Hadoop On CentOS +============================================================ + + [![](https://www.unixmen.com/wp-content/uploads/2015/06/hadoop1-696x249.png "hadoop1")][2] + +The **Apache Hadoop** software library is a framework that allows for the distributed processing of large data sets across clusters of computers using simple programming models The Apache™ Hadoop® project develops open-source software for reliable, scalable, distributed computing. + +The project includes these modules: + +* **Hadoop Common**: The common utilities that support the other Hadoop modules. + +* **Hadoop Distributed File System (HDFS™)**: A distributed file system that provides high-throughput access to application data. + +* **Hadoop YARN**: A framework for job scheduling and cluster resource management. + +* **Hadoop MapReduce**: A YARN-based system for parallel processing of large data sets. + +This article will help you for step by step install and configure single node hadoop cluster using Hadoop on centos. + +### Install Java + +Before installing hadoop make sure you have java installed on your system. Use this command to check the version of the installed Java. + +``` +java -version +java version "1.7.0_75" +Java(TM) SE Runtime Environment (build 1.7.0_75-b13) +Java HotSpot(TM) 64-Bit Server VM (build 24.75-b04, mixed mode) +``` + +To install or update Java use following step by step instructions. + +First step is to download latest version of java from the [Oracle official website][3]. + +``` +cd /opt/ +wget --no-cookies --no-check-certificate --header "Cookie: gpw_e24=http%3A%2F%2Fwww.oracle.com%2F; oraclelicense=accept-securebackup-cookie" "http://download.oracle.com/otn-pub/java/jdk/7u79-b15/jdk-7u79-linux-x64.tar.gz" +tar xzf jdk-7u79-linux-x64.tar.gz +``` + +Need to set up to use newer version of Java using alternatives. Use the following commands to do it. + +``` +cd /opt/jdk1.7.0_79/ +alternatives --install /usr/bin/java java /opt/jdk1.7.0_79/bin/java 2 +alternatives --config java +``` + +``` +There are 3 programs which provide 'java'. + + Selection Command +----------------------------------------------- +* 1 /opt/jdk1.7.0_60/bin/java + + 2 /opt/jdk1.7.0_72/bin/java + 3 /opt/jdk1.7.0_79/bin/java + +Enter to keep the current selection[+], or type selection number: 3 [Press Enter] +``` + +Now you may also required to set up javac and jar commands path using alternatives command. + +``` +alternatives --install /usr/bin/jar jar /opt/jdk1.7.0_79/bin/jar 2 +alternatives --install /usr/bin/javac javac /opt/jdk1.7.0_79/bin/javac 2 +alternatives --set jar /opt/jdk1.7.0_79/bin/jar +alternatives --set javac /opt/jdk1.7.0_79/bin/javac +``` + +The next step is to configure environment variables. Use following commands to set up these variable properly + +* Setup **JAVA_HOME** Variable + +``` +export JAVA_HOME=/opt/jdk1.7.0_79 +``` + +* Setup **JRE_HOME** Variable + +``` +export JRE_HOME=/opt/jdk1.7.0_79/jre +``` + +* Setup **PATH** Variable + +``` +export PATH=$PATH:/opt/jdk1.7.0_79/bin:/opt/jdk1.7.0_79/jre/bin +``` + +### Installing **Apache Hadoop** + +After setting up the java environment. Let stat installing **Apache Hadoop.** + +The first step is to create a system user account to use for hadoop installation. + +``` +useradd hadoop +passwd hadoop +``` + +Now you need to configure the ssh keys for the user hadoop. Using following command to enable ssh login without password. + +``` +su - hadoop +ssh-keygen -t rsa +cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys +chmod 0600 ~/.ssh/authorized_keys +exit +``` + +Now download hadoop latest available version from its official site [hadoop.apache.org][4]. + +``` +cd ~ +wget http://apache.claz.org/hadoop/common/hadoop-2.6.0/hadoop-2.6.0.tar.gz +tar xzf hadoop-2.6.0.tar.gz +mv hadoop-2.6.0 hadoop +``` + +Now the next step is to set environment variable uses by hadoop. + +Edit **~/.bashrc** file and add the following listes of  values at end of file. + +``` +export HADOOP_HOME=/home/hadoop/hadoop +export HADOOP_INSTALL=$HADOOP_HOME +export HADOOP_MAPRED_HOME=$HADOOP_HOME +export HADOOP_COMMON_HOME=$HADOOP_HOME +export HADOOP_HDFS_HOME=$HADOOP_HOME +export YARN_HOME=$HADOOP_HOME +export HADOOP_COMMON_LIB_NATIVE_DIR=$HADOOP_HOME/lib/native +export PATH=$PATH:$HADOOP_HOME/sbin:$HADOOP_HOME/bin +``` + +Then apply the changes in current running environment + +``` +source ~/.bashrc +``` + +edit **$HADOOP_HOME/etc/hadoop/hadoop-env.sh** file and set **JAVA_HOME**environment variable + +``` +export JAVA_HOME=/opt/jdk1.7.0_79/ +``` + +Now you start with the configuration with basic hadoop single node cluster setup. + +First edit hadoop configuration files and make following changes. + +``` + cd /home/hadoop/hadoop/etc/hadoop +``` + +Let’s start by editing core-site.xml + +``` + + + fs.default.name + hdfs://localhost:9000 + + +``` + +Then Edit hdfs-site.xml: + +``` + + + dfs.replication + 1 + + + + dfs.name.dir + file:///home/hadoop/hadoopdata/hdfs/namenode + + + + dfs.data.dir + file:///home/hadoop/hadoopdata/hdfs/datanode + + +``` + +and edit mapred-site.xml: + +``` + + + mapreduce.framework.name + yarn + + +``` + +finally edit yarn-site.xml: + +``` + + + yarn.nodemanager.aux-services + mapreduce_shuffle + + +``` + +Now format the namenode using following command: + +``` +hdfs namenode -format +``` + +To start all hadoop services use the following command: + +``` +cd /home/hadoop/hadoop/sbin/ +start-dfs.sh +start-yarn.sh +``` + +To check if all services are started well use ‘jps‘ command: + +``` +jps +``` + +You should see like this output. + +``` +26049 SecondaryNameNode +25929 DataNode +26399 Jps +26129 JobTracker +26249 TaskTracker +25807 NameNode +``` + +Now you can access to Hadoop Services in your Browser at: **http://your-ip-address:8088/.** + + [![hadoop](http://www.unixmen.com/wp-content/uploads/2015/06/hadoop.png)][5] + +Thanks!!! + +-------------------------------------------------------------------------------- + +via: https://www.unixmen.com/setup-apache-hadoop-centos/ + +作者：[anismaj ][a] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:https://www.unixmen.com/author/anis/ +[1]:https://www.unixmen.com/author/anis/ +[2]:https://www.unixmen.com/wp-content/uploads/2015/06/hadoop1.png +[3]:http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html +[4]:https://hadoop.apache.org/ +[5]:http://www.unixmen.com/wp-content/uploads/2015/06/hadoop.png