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https://issues.apache.org/jira/browse/HDFS-10220?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15265770#comment-15265770
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Nicolas Fraison commented on HDFS-10220:
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[~raviprak] in fact changing from *Lease leaseToCheck = sortedLeases.poll();*
to *Lease leaseToCheck = sortedLeases.peek();* seems better.
But I don't think that we had to add the lease to *removing* in case of
*completed* as it has already been removed by
*fsnamesystem.internalReleaseLease* in *finalizeINodeFileUnderConstruction*.
I also think that we should keep the *removing.add(id);* in case of an
exception, as they seems to be raised (and removed) for good reason:
{code}
// Only the last and the penultimate blocks may be in non COMPLETE state.
// If the penultimate block is not COMPLETE, then it must be COMMITTED.
....
throw new IOException(message);
{code}
and
{code}
// Cannot close file right now, since some blocks
// are not yet minimally replicated.
// This may potentially cause infinite loop in lease recovery
// if there are no valid replicas on data-nodes.
...
throw new AlreadyBeingCreatedException(message);
{code}
What is your feeling about this?
> 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
> Assignee: Nicolas Fraison
> Priority: Minor
> Attachments: HADOOP-10220.001.patch, HADOOP-10220.002.patch,
> HADOOP-10220.003.patch, HADOOP-10220.004.patch, HADOOP-10220.005.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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