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Jian He commented on MAPREDUCE-6513: ------------------------------------ looks like TaskAttemptKillEvent will be sent twice for each mapper First at below code in RMContainerAllocator#handleUpdatedNodes, JobImpl will in turn send the TaskAttemptKillEvent event for each mapper on the unusable node. {code} // send event to the job to act upon completed tasks eventHandler.handle(new JobUpdatedNodesEvent(getJob().getID(), updatedNodes)); {code} Second time at this code in the same method {code} // If map, reschedule next task attempt. boolean rescheduleNextAttempt = (i == 0) ? true : false; eventHandler.handle(new TaskAttemptKillEvent(tid, "TaskAttempt killed because it ran on unusable node" + taskAttemptNodeId, rescheduleNextAttempt)); } {code} This is how it was long time ago, Not sure why that is. With the new change, will this cause more container requests get scheduled ? > MR job got hanged forever when one NM unstable for some time > ------------------------------------------------------------ > > Key: MAPREDUCE-6513 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-6513 > Project: Hadoop Map/Reduce > Issue Type: Bug > Components: applicationmaster, resourcemanager > Affects Versions: 2.7.0 > Reporter: Bob.zhao > Assignee: Varun Saxena > Priority: Critical > Attachments: MAPREDUCE-6513.01.patch, MAPREDUCE-6513.02.patch, > MAPREDUCE-6513.03.patch, MAPREDUCE-6513.3.branch-2.8.patch, > MAPREDUCE-6513.3_1.branch-2.7.patch, MAPREDUCE-6513.3_1.branch-2.8.patch > > > when job is in-progress which is having more tasks,one node became unstable > due to some OS issue.After the node became unstable, the map on this node > status changed to KILLED state. > Currently maps which were running on unstable node are rescheduled, and all > are in scheduled state and wait for RM assign container.Seen ask requests for > map till Node is good (all those failed), there are no ask request after > this. But AM keeps on preempting the reducers (it's recycling). > Finally reducers are waiting for complete mappers and mappers did n't get > container.. > My Question Is: > ============ > why map requests did not sent AM ,once after node recovery.? -- This message was sent by Atlassian JIRA (v6.3.4#6332) --------------------------------------------------------------------- To unsubscribe, e-mail: mapreduce-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: mapreduce-issues-h...@hadoop.apache.org