How to Quick-Start With Apache Hadoop on CentOS 7.x Linux

Hadoop 2.X Quick Start on CentOS 7.x Linux

Hi! The Tutorial shows you Step-by-Step How to Install and Getting-Started with Apache Hadoop/Map-Reduce vanilla in Pseudo-Distributed mode on CentOS 7.x Linux Desktop/Server.

Hadoop is a distributed master-slave that consists of the Hadoop Distributed File System (HDFS) for storage and Map-Reduce for computational capabilities.

The Hadoop Distributed File System (HDFS) is a distributed file system that spreads data blocks across the storage defined for the Hadoop cluster.

The foundation of Hadoop is the two core frameworks YARN and HDFS. These two frameworks deal with Processing and Storage.

The Guide Describe a System-Wide Setup with Root Privileges but you Can Easily Convert the Procedure to a Local One.

The Contents and Details of How to Install Hadoop on CentOS 6 Linux are Expressly Essentials to Give Focus Only to the Essentials Instructions and Commands.

1. Download Latest Apache Hadoop Stable Release:

   Apache Hadoop Binary tar.gz

   Apache Hadoop

2. Double-Click on Archive and Extract Into /tmp Directory.

   

   Or from CLI:

   tar xvzf *hadoop*tar.gz -C /tmp

3. Open a Shell Terminal emulator window
   (Press “Enter” to Execute Commands)

   

   In case first see: Terminal QuickStart Guide.
   Or Login into the Server Shell.

4. Relocate Apache Hadoop Directory
   Get SuperUser Privileges:

   sudo su

   If Got “User is Not in Sudoers file” then see: How to Enable sudo
   Then Switch the contents with:

   mv /tmp/hadoop* /usr/local/

   Make an hadoop symlink directory:

   ln -s /usr/local/hadoop* /usr/local/hadoop

5. Make Hadoop Needed Directories:

   First, Make the Logs Dir:

   mkdir /usr/local/hadoop/logs

   Giving Writing Permissions:

   chmod 777 /usr/local/hadoop/logs

   Next Make the Cache Dir:

   mkdir /usr/local/hadoop/cache

   Same Writing Permissions as for Logs:

   chmod 777 /usr/local/hadoop/cache

   And then also the Temporary Dir:

   mkdir /usr/local/hadoop/tmp

   Set the root as Owner:

   sudo chown -R root:root /usr/local/hadoop*

6. How to Install Required Java JDK 8+ on CentOS Linux

   Install Oracle JDK 8+ for CentOS

   Installing Java Oracle JDK 8+ on CentOS Linux

7. Set JAVA_HOME in Hadoop Env File
   Make the Conf directory:

   mkdir /usr/local/hadoop/conf

   Make an Env file:

   nano /usr/local/hadoop/conf/hadoop-env.sh

   Append:

   export JAVA_HOME=/usr/lib/jvm/[oracleJdkVersion]

   Change [oracleJdkVersion] with the current Version:
   Ctrl+x to Save & Exit from nano Editor :)

Eclipse Hadoop Integration with Free Plugin.

Hadoop Eclipse Plugin SetUp
SetUp Eclipse Hadoop Plugin

8. Hadoop Configuration for Pseudo-Distributed mode

   nano /usr/local/hadoop/conf/core-site.xml

   Append:

   <?xml version="1.0"?>
   <?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
   <configuration>
   <property>
   <name>hadoop.tmp.dir</name>
   <value>/usr/local/hadoop/tmp</value>
   </property>
   <property>
   <name>fs.default.name</name>
   <value>hdfs://localhost:8020</value>
   </property>
   </configuration>
   

   Next:

   nano /usr/local/hadoop/conf/hdfs-site.xml

   Append:

   <?xml version="1.0"?>
   <?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
   <configuration>
   <property>
   <name>dfs.replication</name>
   <value>1</value>
   </property>
   <property>
   <!-- specify this so that running 'hdfs namenode -format'
   formats the right dir -->
   <name>dfs.name.dir</name>
   <value>/usr/local/hadoop/cache/hadoop/dfs/name</value>
   </property>
   </configuration>
   

   Last:

   nano /usr/local/hadoop/conf/mapred-site.xml

   Append:

   <?xml version="1.0"?>
   <?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
   <configuration>
   <property>
   <name>mapred.job.tracker</name>
   <value>localhost:8021</value>
   </property>
   </configuration>
   

9. SetUp Local Path & Environment
   Exit from SuperUser to the normal User:

   exit

   Change to the Home directory:

   cd  

   Edit the bash Config file:

   nano .bashrc

   Inserts:

   HADOOP_HOME=/usr/local/hadoop/nexport PATH=$PATH:$HADOOP_HOME/bin:$HADOOP_HOME/sbin/nexport JAVA_HOME=/usr/lib/jvm/<oracleJdkVersion>

   Then Load the New Setup:

   source $HOME/.bashrc

10. SetUp Needed Local SSH Connection

    sudo systemctl start ssh

    Generate SSH Keys to Access:

    ssh-keygen -b 2048 -t rsa

    echo "$(cat ~/.ssh/id_rsa.pub)" > ~/.ssh/authorized_keys

    Testing Connection:

    ssh 127.0.0.1

11. Formatting HDFS

    hdfs namenode -format

    

12. Starting Up Hadoop Database

    start-all.sh

13. Apache Hadoop Database Quick Start Guide

    Hadoop MapReduce Quick Start

    The Linked Guide Contains a Step-by-Step Jump Start Guide for Apache Hadoop Database