[YARN-3967] Fetch the application report from the AHS if the RM does not know about it

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.7.1
• Fix Version/s: 2.8.0, 2.7.2, 3.0.0-alpha1
• Target Version/s: 2.7.2
• Assignee: Mit Desai
• Reporter: Mit Desai
• Created: 23/Jul/15 18:03
• Updated: 02/Dec/16 01:11
• Resolved: 24/Jul/15 17:19

Description

If the application history service has been enabled and RM has forgotten anout an application, try and fetch the app report form the AHS.

On larger clusters, the RM can forget about the applications in about 30 minutes. The proxy url generated during the job submission will try to fetch the app report from the RM and will fail to get anything from there. If the app is not found in the RM, we will need to get the application report from the Application History Server (if it is enabled) to see if we can get any information on that application before throwing an exception.