[YARN-3389] Avoid race conditions when attempts operate on shared states concurrently

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Not A Problem
• Affects Version/s: 2.6.0
• Component/s: resourcemanager
• Assignee: Jun Gong
• Reporter: Jun Gong
• Created: 23/Mar/15 15:06
• Updated: 14/Apr/15 07:26
• Resolved: 14/Apr/15 07:26

Description

In AttemptFailedTransition, new attempt will get states('justFinishedContainers' and 'finishedContainersSentToAM') reference from failed attempt. Then these attempts share the two states(previous attempts also share the two states). Suppose two or more CONTAINER_FINISHED events for different attempts are handled at the same time, and suppose they ran on same node. Attempts will update justFinishedContainers's same key's value concurrently. Although 'justFinishedContainers' is a ConcurrentHashMap, operations on its value 'List<ContainerStatus>' is not atomic, namely

appAttempt.justFinishedContainers.get(containerFinishedEvent.getNodeId()).add(containerFinishedEvent.getContainerStatus())

is not atomic.