[jira] Resolved: (MAPREDUCE-2175) speculation framework does not update job progress rate with time causing false speculation

["Joydeep Sen Sarma (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/MAPREDUCE-2175?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Joydeep Sen Sarma resolved MAPREDUCE-2175.
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    Resolution: Duplicate

sorry - already opened mapreduce-2062 covering this

> speculation framework does not update job progress rate with time causing false speculation
> -------------------------------------------------------------------------------------------
>
>                 Key: MAPREDUCE-2175
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-2175
>             Project: Hadoop Map/Reduce
>          Issue Type: Bug
>          Components: jobtracker
>            Reporter: Joydeep Sen Sarma
>
> When considering task speculation - the job's overall progress rate for the given task type and the individual task's progress rate are compared. When doing so - the task's current progress rate is considered. However the job's overall progress rate is only only updated when a task's progress report is received.
> This causes weirdness if a particular task does not report for a while. The job's progress rate is not updated - but the task's progress rate decays. For single task jobs - it causes speculation almost inevitably. 
> We need to update the job's overall progress rate as the task's progress rate changes.

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