[YARN-125] Make Yarn Client service shutdown operations robust

• Type: Sub-task
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.1.0-beta
• Assignee: Steve Loughran
• Reporter: Steve Loughran
• Created: 16/Mar/12 15:35
• Updated: 27/Aug/13 22:15
• Resolved: 13/Jun/13 16:57

Description

Make the yarn client services more robust against being shut down while not started, or shutdown more than once, by null-checking fields before closing them, setting to null afterwards to prevent double-invocation. This is a subset of MAPREDUCE-3502

Issue Links

• is part of: YARN-117 Enhance YARN service model