Installation of Hadoop on Linux

Steps to Install hadoop on  ubuntu

1. Install Jdk 1.6 or greater here.
     to install jdk write 
 $ sudo apt-get install openjdk-8-jdk

2. Download the required hadoop .

3. Extract by tar xvzf hadoop-2.6.0.tar.gz

4. update the JAVA_HOME inside the hadoop-env.sh file.
--write
export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-i386

5. Update your bashrc file by 

    $sudo gedit .bashrc

paste this export lines at the end of file

export HADOOP_HOME=/home/ratul/hadoop-2.6.0
export HADOOP_CONF_DIR=/home/ratul/hadoop-2.6.0/etc/hadoop
export HADOOP_MAPRED_HOME=/home/ratul/hadoop-2.6.0
export HADOOP_COMMON_HOME=/home/ratul/hadoop-2.6.0
export HADOOP_HDFS_HOME=/home/ratul/hadoop-2.6.0
export YARN_HOME=/home/ratul/hadoop-2.6.0

export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-i386
export PATH=$PATH:/home/ratul/hadoop-2.6.0/bin

export HADOOP_USER_CLASSPATH_FIRST=true

6. modify your core-site.xml hdfs-site.xml and mapred-site.xml.

7. Install ssh on your system using sudo apt-get install ssh.

8. ssh localhost should log you in.

9. run the below two commands to save the auth keys.
       $ ssh-keygen -t dsa -P '' -f ~/.ssh/id_dsa
       $ cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys

10. now your system is setup and installed with hadoop, format your namenode by

     $ hadoop namenode -format

11. To run your namenode,datanode,secondarynamenode,jobtracker and tasktracker.

     $ cd home/ratul/hadoop-2.6.0/sbin
     $./start-all.sh

12. You can view the namenode http://localhost:50070

13. You can view the cluster at http://localhost:8088

14. You can interact with hdfs using hadoop fs -ls /