[HADOOP-5473] Race condition in command-line kill for a task

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.20.0
• Hadoop Flags: Reviewed
• Assignee: Amareshwari Sriramadasu
• Reporter: Amareshwari Sriramadasu
• Created: 12/Mar/09 08:05
• Updated: 08/Jul/09 16:53
• Resolved: 30/Mar/09 12:04

Description

The race condition occurs in following sequence of events:
1. User issues a command-line kill for a RUNNING map-task. JT stores the task in tasksToKill mapping.
2. TT reports the task status as SUCCEEDED.
3. JT creates a TaskCompletionEvent as SUCCEEDED. Also sends a killTaskAction.
4. Reducers fail fetching the map output.
5. finally, the task would fail with Fetch failures. After HADOOP-4759, the task is left as FAILED_UNCLEAN task, since the task is present in tasksToKill mapping.