The JobTracker lock can be a reader/writer lock -----------------------------------------------
Key: MAPREDUCE-1797 URL: https://issues.apache.org/jira/browse/MAPREDUCE-1797 Project: Hadoop Map/Reduce Issue Type: Improvement Components: jobtracker Reporter: dhruba borthakur The Jobtracker has a global lock and a per-job JobInProgress lock. The aim for the JobInprogress lock is to support the ability to lock a single job's metadata without blocking out the entire JobTracker. However, many code paths acquire the JobTracker lock and then acquire the JobInProgress lock while keeping the JobTracker lock. This somewhat defeats the benefit of having a per-job lock. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.