The Enterprise Console shows an empty MapReduce Jobs table on the Application Status tab momentarily and then shows MapReduce jobs in the Jobs table again (auto-refresh enabled).
This is caused when the Enterprise Console is unable to obtain a list of MapReduce jobs from the Hadoop JobTracker. This could happen if the Hadoop JobTracker is under heavy load and too busy handling MapReduce jobs, is short on resources, or is just restarted.
Resolving the problem
You should be aware that when JobTracker is busy, short on resources, or just gets restarted, the Enterprise Console might show no MapReduce jobs on the Application Status tab. With auto refresh enabled, the Console should display jobs again once the JobTracker starts to return job information.