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https://issues.apache.org/jira/browse/HDFS-11817?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16019886#comment-16019886
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Kihwal Lee commented on HDFS-11817:
-----------------------------------

Two test failures are real.
{noformat}
TestRetryCacheWithHA#testCheckLease
TestLeaseManager#testCheckLease
{noformat}

{{TestLeaseManager}} was failing because I made failed lease recoveries to be 
retried. In the new patch, I made it give up and remove the lease if an 
IOException is thrown because of a bad path.  For all other cases, it is 
correct to retry, since they are likely transient conditions.

{{TestRetryCacheWithHA}} was failing because the test passed fake storage IDs 
to {{updatePipeline()}}, despite it has the real storage IDs available. Updated 
the test.

I will upload the trunk version shortly with these changes.

> A faulty node can cause a lease leak and NPE on accessing data
> --------------------------------------------------------------
>
>                 Key: HDFS-11817
>                 URL: https://issues.apache.org/jira/browse/HDFS-11817
>             Project: Hadoop HDFS
>          Issue Type: Bug
>    Affects Versions: 2.8.0
>            Reporter: Kihwal Lee
>            Assignee: Kihwal Lee
>            Priority: Critical
>         Attachments: HDFS-11817.branch-2.patch, hdfs-11817_supplement.txt
>
>
> When the namenode performs a lease recovery for a failed write, the 
> {{commitBlockSynchronization()}} will fail, if none of the new target has 
> sent a received-IBR.  At this point, the data is inaccessible, as the 
> namenode will throw a {{NullPointerException}} upon {{getBlockLocations()}}.
> The lease recovery will be retried in about an hour by the namenode. If the 
> nodes are faulty (usually when there is only one new target), they may not 
> block report until this point. If this happens, lease recovery throws an 
> {{AlreadyBeingCreatedException}}, which causes LeaseManager to simply remove 
> the lease without  finalizing the inode.  
> This results in an inconsistent lease state. The inode stays 
> under-construction, but no more lease recovery is attempted. A manual lease 
> recovery is also not allowed. 



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