[MAPREDUCE-1495] Reduce locking contention on JobTracker.getTaskCompletionEvents()

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 0.20.1
• Assignee: Unassigned
• Reporter: Rajesh Balamohan
• Created: 15/Feb/10 13:04
• Updated: 16/Feb/10 19:52
• Resolved: 16/Feb/10 19:52

Description

While profiling JT for slow performance with small-jobs, it was observed that JobTracker.getTaskCompletionEvents() is attributing to 40% of lock contention on JT.

This JIRA ticket is created to explore the possibilities of reducing the sychronized code block in this method.