I was working on my EMR cluster and needed to test some issues with steps of our process but I don’t have access to the web tools to monitor processes. When I ran one of my hadoop processes it just sat at the beginning of the process. It turned out I had some hung processes but needed to use the Hadoop yarn command-line tool to find out what was going on.

Using the following command shows the queue for processes queued to run:

> yarn application -list

If you do find an issue with a hung process, use the following to end the process:

>yarn application -kill <application-id>

Tags: BigData