Perform below steps on the servers chosen for Datanodes having different OS version
2. Manage Stack Version
Go to Ambari Versions page:
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 188.8.131.52
wget -nv http://public-repo-1.hortonworks.com/ambari/centos7/2.x/updates/184.108.40.206/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
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.