Use the following instructions to validate that the NameNode and the NameNode monitoring agent are started automatically on server restart:
Step 1:Reboot the NameNode machine.
Step 2:Verify that the NameNode service is up and running.
On the NameNode machine, execute the following command:
service hadoop-namenode status
If the service is up and running, you should see a message similar to the one shown in the following example:
namenode (pid 4651) is running...
Step 3:Verify that the NameNode monitoring agent is up and running.
On the NameNode machine, execute the following command:
service hmonitor-namenode-monitor status
If the service is up and running, you should see a message similar to the one shown in the following example:
java (pid 4870) is running...