Use the following instructions to validate that both the NameNode service and the monitoring agent automatically get started on the reboot of the NameNode machine:
Reboot the NameNode machine.
Verify that the NameNode service is up and running.
On the NameNode machine, list all the Java processes by invoking jps and look for NameNode process:
$JDK_HOME/bin/jps
If the service is up and running, you should see a message similar to the one shown in the following example:
1628 NameNode
Verify that the NameNode monitoring agent is up and running.
On the NameNode machine, list all the Java processes by invoking jps and look for NameNode process:
$JDK_HOME/bin/jps
If the service is up and running, you should see a message similar to the one shown in the following example:
1814 NameNodeMonitor