Install New DataNodes In a Mix OS Cluster

[#1]

Perform below steps on the servers chosen for Datanodes having different OS version

1. Prerequisites

• Minimum Software Requirements:

https://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.6.2/bk_support-matrices/content/ch_matrices-amb...

• Check and set the maximum Open File descriptors on new host

https://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.6.2/bk_support-matrices/content/ch_matrices-amb...

• Check DNS and NSCD

https://docs.hortonworks.com/HDPDocuments/Ambari-2.5.2.0/bk_ambari-installation/content/check_dns.ht...

• Disable THP
• Disable SELinux
• Enable NTP
• Swappiness
• Install same Python version
• Install same JDK Version

2. Manage Stack Version

Go to Ambari Versions page:

http://<ambariHost>:<ambariPort>/views/ADMIN_VIEW/<ambariVersion>/INSTANCE/#/stackVersions

Replace <ambariHost>, <ambariPort>,<ambariVersion> with values from your cluster.

Select current version.

Add repository details for RHEL7

3.Manually download and Install Ambari agent

3.1 Download Ambari repo

wget -nv http://public-repo-1.hortonworks.com/ambari/centos7/2.x/updates/<version>/ambari.repo -O /etc/yum.repos.d/ambari.repo

Below command downloads the latest Ambari version 2.6.1.5

wget -nv http://public-repo-1.hortonworks.com/ambari/centos7/2.x/updates/2.6.1.5/ambari.repo -O /etc/yum.repos.d/ambari.repo

3.2 Install Ambari Agent

4. Manually register the hosts in Ambari

5. Validate the OS Family for stack and versions in Ambari

6. Complete the installation and validate the host in the hosts list

7.Test with a Job

7.1 Testing with a Terasort job

/usr/hdp/current/hadoop-client/bin/hadoop \

jar /usr/hdp/current/hadoop-mapreduce-client/hadoop-mapreduce-examples-*.jar \

terasort /tmp/teragenout /tmp/terasortout

7.2 Validate by checking with a Terasort job

When you run a new job, the recently added Datanode will have most resources available and some containers from your new job will land on this new host.

From Yarn RM UI, validate if any container landed on this new host and confirm that they finish their execution successfully.