[HDFS-9141] Thread leak in Datanode#refreshVolumes

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.7.1, 3.0.0-alpha1
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Component/s: datanode
• Hadoop Flags: Reviewed
• Assignee: Uma Maheswara Rao G
• Reporter: Uma Maheswara Rao G
• Created: 24/Sep/15 21:21
• Updated: 30/Aug/16 01:26
• Resolved: 29/Sep/15 14:17

Description

In refreshVolumes, we are creating executor service and submitting volume addition tasks to it.
But we are not shutting down the service after the use. Even though we are not holding instance level service, the initialized thread could be left out.

ExecutorService service = Executors.newFixedThreadPool(
            changedVolumes.newLocations.size());

So, simple fix for this would be to shutdown the service after its use.