How to Setup Hadoop on Ubuntu 18.04 & 16.04 LTS

Apache Hadoop 3.1 have noticeable improvements any many bug fixes over the previous stable 3.0 releases. This version has many improvements in HDFS and MapReduce. This tutorial will help you to install and configure Hadoop 3.1.2 Single-Node Cluster on Ubuntu 18.04, 16.04 LTS and LinuxMint Systems. This article has been tested with Ubuntu 18.04 LTS.

Step 1 – Prerequsities

Java is the primary requirement for running Hadoop on any system, So make sure you have Java installed on your system using the following command. If you don’t have Java installed on your system, use one of the following links to install it first.

• Install Oracle Java 11 on Ubuntu 18.04 LTS (Bionic)
• Install Oracle Java 11 on Ubuntu 16.04 LTS (Xenial)

Step 2 – Create User for Haddop

We recommend creating a normal (nor root) account for Hadoop working. To create an account using the following command.

adduser hadoop

After creating the account, it also required to set up key-based ssh to its own account. To do this use execute following commands.

su - hadoop
ssh-keygen -t rsa -P '' -f ~/.ssh/id_rsa
cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
chmod 0600 ~/.ssh/authorized_keys

Now, SSH to localhost with Hadoop user. This should not ask for the password but the first time it will prompt for adding RSA to the list of known hosts.

ssh localhost
exit

Step 3 – Download Hadoop Source Archive

In this step, download hadoop 3.1 source archive file using below command. You can also select alternate download mirror for increasing download speed.

cd ~
wget http://www-eu.apache.org/dist/hadoop/common/hadoop-3.1.2/hadoop-3.1.2.tar.gz
tar xzf hadoop-3.1.2.tar.gz
mv hadoop-3.1.2 hadoop

Step 4 – Setup Hadoop Pseudo-Distributed Mode

4.1. Setup Hadoop Environment Variables

Setup the environment variables used by the Hadoop. Edit ~/.bashrc file and append following 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 the current running environment

source ~/.bashrc

Now edit $HADOOP_HOME/etc/hadoop/hadoop-env.sh file and set JAVA_HOME environment variable. Change the JAVA path as per install on your system. This path may vary as per your operating system version and installation source. So make sure you are using the correct path.

vim $HADOOP_HOME/etc/hadoop/hadoop-env.sh

Update below entry:

export JAVA_HOME=/usr/lib/jvm/java-11-oracle

4.2. Setup Hadoop Configuration Files

Hadoop has many configuration files, which need to configure as per requirements of your Hadoop infrastructure. Let’s start with the configuration with basic Hadoop single node cluster setup. first, navigate to below location

cd $HADOOP_HOME/etc/hadoop

Edit core-site.xml

<configuration>
<property>
  <name>fs.default.name</name>
    <value>hdfs://localhost:9000</value>
</property>
</configuration>

Edit hdfs-site.xml

<configuration>
<property>
 <name>dfs.replication</name>
 <value>1</value>
</property>

<property>
  <name>dfs.name.dir</name>
    <value>file:///home/hadoop/hadoopdata/hdfs/namenode</value>
</property>

<property>
  <name>dfs.data.dir</name>
    <value>file:///home/hadoop/hadoopdata/hdfs/datanode</value>
</property>
</configuration>

Edit mapred-site.xml

<configuration>
 <property>
  <name>mapreduce.framework.name</name>
   <value>yarn</value>
 </property>
</configuration>

Edit yarn-site.xml

<configuration>
 <property>
  <name>yarn.nodemanager.aux-services</name>
    <value>mapreduce_shuffle</value>
 </property>
</configuration>

4.3. Format Namenode

Now format the namenode using the following command, make sure that Storage directory is

hdfs namenode -format

Sample output:

WARNING: /home/hadoop/hadoop/logs does not exist. Creating.
2018-05-02 17:52:09,678 INFO namenode.NameNode: STARTUP_MSG:
/************************************************************
STARTUP_MSG: Starting NameNode
STARTUP_MSG:   host = tecadmin/127.0.1.1
STARTUP_MSG:   args = [-format]
STARTUP_MSG:   version = 3.1.2
...
...
...
2018-05-02 17:52:13,717 INFO common.Storage: Storage directory /home/hadoop/hadoopdata/hdfs/namenode has been successfully formatted.
2018-05-02 17:52:13,806 INFO namenode.FSImageFormatProtobuf: Saving image file /home/hadoop/hadoopdata/hdfs/namenode/current/fsimage.ckpt_0000000000000000000 using no compression
2018-05-02 17:52:14,161 INFO namenode.FSImageFormatProtobuf: Image file /home/hadoop/hadoopdata/hdfs/namenode/current/fsimage.ckpt_0000000000000000000 of size 391 bytes saved in 0 seconds .
2018-05-02 17:52:14,224 INFO namenode.NNStorageRetentionManager: Going to retain 1 images with txid >= 0
2018-05-02 17:52:14,282 INFO namenode.NameNode: SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode at tecadmin/127.0.1.1
************************************************************/

Step 5 – Start Hadoop Cluster

Let’s start your Hadoop cluster using the scripts provides by Hadoop. Just navigate to your $HADOOP_HOME/sbin directory and execute scripts one by one.

cd $HADOOP_HOME/sbin/

Now execute start-dfs.sh script.

./start-dfs.sh

Then execute start-yarn.sh script.

./start-yarn.sh

Step 6 – Access Hadoop Services in Browser

Hadoop NameNode started on default port 9870. Access your server on port 9870 in your favorite web browser.

http://svr1.tecadmin.net:9870/

Now access port 8042 for getting the information about the cluster and all applications

http://svr1.tecadmin.net:8042/

Access port 9864 to get details about your Hadoop node.

http://svr1.tecadmin.net:9864/

Step 7 – Test Hadoop Single Node Setup

7.1. Make the HDFS directories required using following commands.

bin/hdfs dfs -mkdir /user
bin/hdfs dfs -mkdir /user/hadoop

7.2. Copy all files from local file system /var/log/httpd to hadoop distributed file system using below command

bin/hdfs dfs -put /var/log/apache2 logs

7.3. Browse Hadoop distributed file system by opening below URL in the browser. You will see an apache2 folder in the list. Click on the folder name to open and you will find all log files there.

 http://svr1.tecadmin.net:9870/explorer.html#/user/hadoop/logs/

7.4 – Now copy logs directory for hadoop distributed file system to local file system.

bin/hdfs dfs -get logs /tmp/logs
ls -l /tmp/logs/

You can also check this tutorial to run wordcount mapreduce job example using command line.