[HDFS-4882] Prevent the Namenode's LeaseManager from looping forever in checkLeases

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 2.0.0-alpha, 2.5.1
• Fix Version/s: 2.6.1, 3.0.0-alpha1
• Component/s: hdfs-client, namenode
• Labels: 2.6.1-candidate
• Target Version/s: 2.6.1
• Assignee: Ravi Prakash
• Reporter: Zesheng Wu
• Created: 05/Jun/13 11:27
• Updated: 30/Aug/16 01:42
• Resolved: 24/Nov/14 18:56

Description

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:

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]

(the 3rd line log is a debug log added by us)

Issue Links

• incorporates: HDFS-7342 Lease Recovery doesn't happen some times
• is related to: HDFS-8344 NameNode doesn't recover lease for files with missing blocks
• relates to: HDFS-7307 Need 'force close'