[YARN-5436] Race in AsyncDispatcher can cause random test failures in Tez (probably YARN also)

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.9.0, 3.0.0-alpha1
• Hadoop Flags: Reviewed
• Assignee: Zhiyuan Yang
• Reporter: Zhiyuan Yang
• Created: 26/Jul/16 23:30
• Updated: 30/Aug/16 00:59
• Resolved: 28/Jul/16 23:53

Description

In YARN-2264, a race in DrainDispatcher was fixed. Unfortunately, it also exists in AsyncDispatcher (this was found and ignored in YARN-3878 but never documented...). In YARN-2991, another DrainDispatcher bug was fixed by letting DrainDispatcher reuse some AsyncDispatcher method because AsyncDispatcher doesn't have such issue. However, this shadows YARN-2264, and now similar race reappears in Tez unit tests (probably also YARN unit tests also).

Issue Links

• breaks: YARN-1121 RMStateStore should flush all pending store events before closing
• breaks: YARN-5526 DrainDispacher#ServiceStop blocked if setDrainEventsOnStop invoked
• breaks: TEZ-2852 TestVertexImpl fails due to race in AsyncDispatcher
• is broken by: YARN-2991 TestRMRestart.testDecomissionedNMsMetricsOnRMRestart intermittently fails on trunk
• is related to: YARN-3887 Support for changing Application priority during runtime
• relates to: YARN-2264 Race in DrainDispatcher can cause random test failures