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https://issues.apache.org/jira/browse/MAPREDUCE-125?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Allen Wittenauer resolved MAPREDUCE-125.
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Resolution: Incomplete
Stale!
> JobTracker might wrongly log a tip as failed
> --------------------------------------------
>
> Key: MAPREDUCE-125
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-125
> Project: Hadoop Map/Reduce
> Issue Type: Bug
> Reporter: Amar Kamat
>
> Consider the following case
> 1) attempt _attempt_1_0_ from tip _tip_1_ that ran on tracker _tracker_1_
> failed
> 2) jobtracker will mark _attempt_1_0_ for removal under _tracker_1_. Marking
> basically means removal of the mapping _tracker_1_->_attempt_1_0_
> 3) Marked attempts are removed only on next heartbeat from _tracker__1 or
> when _tracker_1_ is lost.
> 4) Consider a case where _tracker_1_ goes down.
> 5) In the meanwhile attempt _attempt_1_1_ succeeds on _tracker_2_ and the
> jobtracker marks the tip _tip_1_ as complete
> 6) Now the expiry-tracker thread detect that _tracker_1_ is lost and fails
> all the attempt under _tracker_1_.
> 7) Here the jobtracker will kill _attempt_1_0_ *again* and log tip _tip_1_ as
> failed in the history although tip _tip_1_ is really complete/succeeded.
> The events in the history file would be something like
> {noformat}
> tip_1 start
> ---------
> attempt_1_0 start
> attempt_1_0 failed
> ---------
> attempt_1_1 start
> attempt_1_1 finished
> tip_1 finished
> ---------
> tip_1 failed
> {noformat}
> Note that this true even for tasks that expire. Tasks that are scheduled and
> never come back are killed by the {{ExpireLaunchingTasks}} thread. It will
> also call {{JobInProgress.failedTask()}} which will fail the attempt and log
> the TIP as failed.
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