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https://issues.apache.org/jira/browse/HDFS-4882?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13697787#comment-13697787
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Zesheng Wu commented on HDFS-4882:
----------------------------------

{quote}
File will not be finalized until it reached at least min replication blocks. 
But block replication can be started once it is committed to DN.(here each DN 
will finalize its block and report NN). On reaching min replication NN will 
complete that block. If all Blocks in NN are in complete state then file can be 
closed normally.
{quote}
Yes, I think you are right. But the block replication is not committed to DN, 
so is not started.
                
> Namenode LeaseManager checkLeases() runs into infinite loop
> -----------------------------------------------------------
>
>                 Key: HDFS-4882
>                 URL: https://issues.apache.org/jira/browse/HDFS-4882
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: hdfs-client, namenode
>    Affects Versions: 2.0.0-alpha
>            Reporter: Zesheng Wu
>         Attachments: 4882.1.patch, 4882.patch, 4882.patch
>
>
> Scenario:
> 1. cluster with 4 DNs
> 2. the size of the file to be written is a little more than one block
> 3. write the first block to 3 DNs, DN1->DN2->DN3
> 4. all the data packets of first block is successfully acked and the client 
> sets the pipeline stage to PIPELINE_CLOSE, but the last packet isn't sent out
> 5. DN2 and DN3 are down
> 6. client recovers the pipeline, but no new DN is added to the pipeline 
> because of the current pipeline stage is PIPELINE_CLOSE
> 7. client continuously writes the last block, and try to close the file after 
> written all the data
> 8. NN finds that the penultimate block doesn't has enough replica(our 
> dfs.namenode.replication.min=2), and the client's close runs into indefinite 
> loop(HDFS-2936), and at the same time, NN makes the last block's state to 
> COMPLETE
> 9. shutdown the client
> 10. the file's lease exceeds hard limit
> 11. LeaseManager realizes that and begin to do lease recovery by call 
> fsnamesystem.internalReleaseLease()
> 12. but the last block's state is COMPLETE, and this triggers lease manager's 
> infinite loop and prints massive logs like this:
> {noformat}
> 2013-06-05,17:42:25,695 INFO 
> org.apache.hadoop.hdfs.server.namenode.LeaseManager: Lease [Lease.  Holder: 
> DFSClient_NONMAPREDUCE_-1252656407_1, pendingcreates: 1] has expired hard
>  limit
> 2013-06-05,17:42:25,695 INFO 
> org.apache.hadoop.hdfs.server.namenode.FSNamesystem: Recovering lease=[Lease. 
>  Holder: DFSClient_NONMAPREDUCE_-1252656407_1, pendingcreates: 1], src=
> /user/h_wuzesheng/test.dat
> 2013-06-05,17:42:25,695 WARN org.apache.hadoop.hdfs.StateChange: DIR* 
> NameSystem.internalReleaseLease: File = /user/h_wuzesheng/test.dat, block 
> blk_-7028017402720175688_1202597,
> lastBLockState=COMPLETE
> 2013-06-05,17:42:25,695 INFO 
> org.apache.hadoop.hdfs.server.namenode.LeaseManager: Started block recovery 
> for file /user/h_wuzesheng/test.dat lease [Lease.  Holder: DFSClient_NONM
> APREDUCE_-1252656407_1, pendingcreates: 1]
> {noformat}
> (the 3rd line log is a debug log added by us)

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