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https://issues.apache.org/jira/browse/HDFS-10220?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15218247#comment-15218247
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Nicolas Fraison commented on HDFS-10220:
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[~vinayrpet] the day we face this kind of failover we have faced multiple
failover with the same issue on both namenodes. It happens after a bad action
on the cluster removing the mapreduce.jobhistory.intermediate-done-dir folder
whith then lots of mapreduce failing...
Since we have applied this patch we have one time reached 250K lease to release
taking a total time of 45 seconds (having 100 k lease treated per cycle).
> Namenode failover due to too long loking in LeaseManager.Monitor
> ----------------------------------------------------------------
>
> Key: HDFS-10220
> URL: https://issues.apache.org/jira/browse/HDFS-10220
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: namenode
> Reporter: Nicolas Fraison
> Priority: Minor
> Attachments: HADOOP-10220.001.patch, threaddump_zkfc.txt
>
>
> I have faced a namenode failover due to unresponsive namenode detected by the
> zkfc with lot's of WARN messages (5 millions) like this one:
> _org.apache.hadoop.hdfs.StateChange: BLOCK* internalReleaseLease: All
> existing blocks are COMPLETE, lease removed, file closed._
> On the threaddump taken by the zkfc there are lots of thread blocked due to a
> lock.
> Looking at the code, there are a lock taken by the LeaseManager.Monitor when
> some lease must be released. Due to the really big number of lease to be
> released the namenode has taken too many times to release them blocking all
> other tasks and making the zkfc thinking that the namenode was not
> available/stuck.
> The idea of this patch is to limit the number of leased released each time we
> check for lease so the lock won't be taken for a too long time period.
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