Zesheng Wu created HDFS-4882:
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             Summary: Namenode 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


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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