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Hemanth Yamijala commented on MAPREDUCE-1398: --------------------------------------------- bq. The patch did not introduce any new unsynchronized code. I verified this. Also, per comment from Chris in MAPREDUCE-1497, IndexCache is probably already thead-safe. Hence, this might be a legitimate case of suppressing findbugs warning. Based on this, I think the patch is ready for commit. > TaskLauncher remains stuck on tasks waiting for free nodes even if task is > killed. > ---------------------------------------------------------------------------------- > > Key: MAPREDUCE-1398 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-1398 > Project: Hadoop Map/Reduce > Issue Type: Bug > Components: tasktracker > Reporter: Hemanth Yamijala > Assignee: Amareshwari Sriramadasu > Fix For: 0.22.0 > > Attachments: patch-1398-1.txt, patch-1398-2.txt, > patch-1398-ydist.txt, patch-1398.txt > > > Tasks could be assigned to trackers for slots that are running other tasks in > a commit pending state. This is an optimization done to pipeline task > assignment and launch. When the task reaches the tracker, it waits until > sufficient slots become free for it. This wait is done in the TaskLauncher > thread. Now, while waiting, if the task is killed externally (maybe because > the job finishes, etc), the TaskLauncher is not notified of this. So, it > continues to wait for the killed task to get sufficient slots. If slots do > not become free for a long time, this would result in considerable delay in > waking up the TaskLauncher thread. If the waiting task happens to be a high > RAM task, then it is also wasteful, because by waking up, it can make way for > normal tasks that can run on the available number of slots. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.