Hadoop Setup Tutorial - Installation & Configuration

Prerequisites:

You must have Ubuntu installed and running

You must have Java Installed.

Step 1) Add a Hadoop system user using below command

sudo addgroup hadoop_

sudo adduser --ingroup hadoop_ hduser_

Enter your password , name and other details.

NOTE:

There is a possibility of below mentioned error in this setup and installation process.

"hduser is not in the sudoers file. This incident will be reported."

This error can be resolved by

Execute the command

sudo adduser hduser_ sudo

Re-login as hduser_

Step 2) . Configure SSH

In order to manage nodes in a cluster, Hadoop require SSH access

First, switch user, enter following command

su - hduser_

This command will create a new key.

ssh-keygen -t rsa -P ""

Enable SSH access to local machine using this key.

cat $HOME/.ssh/id_rsa.pub >> $HOME/.ssh/authorized_keys

Now test SSH setup by connecting to locahost as 'hduser' user.

ssh localhost

Note:

Please note, if you see below error in response to 'ssh localhost', then there is a possibility that SSH is not available on this system-

To resolve this -

Purge SSH using,

sudo apt-get purge openssh-server

It is good practice to purge before start of installation

Install SSH using command-

sudo apt-get install openssh-server

Step 3) Next step is to Download Hadoop

Select Stable

Select the tar.gz file ( not the file with src)

Once download is complete, navigate to the directory containing the tar file

Enter , sudo tar xzf hadoop-2.2.0.tar.gz

Now, rename rename hadoop-2.2.0 as hadoop

sudo mv hadoop-2.2.0 hadoop

sudo chown -R hduser_:hadoop_ hadoop

Step 4) Modify ~/.bashrc file

Add following lines to end of file ~/.bashrc

#Set HADOOP_HOME
export HADOOP_HOME=<Installation Directory of Hadoop>
#Set JAVA_HOME
export JAVA_HOME=<Installation Directory of Java>
# Add bin/ directory of Hadoop to PATH
export PATH=$PATH:$HADOOP_HOME/bin

Now, source this environment configuration using below command

. ~/.bashrc

Step 5) Configurations related to HDFS

Set JAVA_HOME inside file $HADOOP_HOME/etc/hadoop/hadoop-env.sh

With

There are two parameters in $HADOOP_HOME/etc/hadoop/core-site.xml which need to be set-

1. 'hadoop.tmp.dir' - Used to specify directory which will be used by Hadoop to store its data files.

2. 'fs.default.name' - This specifies the default file system.

To set these parameters, open core-site.xml

sudo gedit $HADOOP_HOME/etc/hadoop/core-site.xml

Copy below line in between tags <configuration></configuration>

<property>
<name>hadoop.tmp.dir</name>
<value>/app/hadoop/tmp</value>
<description>Parent directory for other temporary directories.</description>
</property>
<property>
<name>fs.defaultFS </name>
<value>hdfs://localhost:54310</value>
<description>The name of the default file system. </description>
</property>

Navigate to the directory $HADOOP_HOME/etc/Hadoop

Now, create the directory mentioned in core-site.xml

sudo mkdir -p <Path of Directory used in above setting>

Grant permissions to the directory

sudo chown -R hduser_:Hadoop_ <Path of Directory created in above step>

sudo chmod 750 <Path of Directory created in above step>

Step 6) Map Reduce Configuration

Before you begin with these configurations, lets set HADOOP_HOME path

sudo gedit /etc/profile.d/hadoop.sh

And Enter

export HADOOP_HOME=/home/guru99/Downloads/Hadoop

Next enter

sudo chmod +x /etc/profile.d/hadoop.sh

Exit the Terminal and restart again

Type echo $HADOOP_HOME. To verify the path

Now copy files

sudo cp $HADOOP_HOME/etc/hadoop/mapred-site.xml.template $HADOOP_HOME/etc/hadoop/mapred-site.xml

Open the mapred-site.xml file

sudo gedit $HADOOP_HOME/etc/hadoop/mapred-site.xml

Add below lines of setting in between tags <configuration> and </configuration>

<property>
<name>mapreduce.jobtracker.address</name>
<value>localhost:54311</value>
<description>MapReduce job tracker runs at this host and port.
</description>
</property>

Open $HADOOP_HOME/etc/hadoop/hdfs-site.xml as below,

sudo gedit $HADOOP_HOME/etc/hadoop/hdfs-site.xml

Add below lines of setting between tags <configuration> and </configuration>

<property>
<name>dfs.replication</name>
<value>1</value>
<description>Default block replication.</description>
</property>
<property>
<name>dfs.datanode.data.dir</name>
<value>/home/hduser_/hdfs</value>
</property>