[
https://issues.apache.org/jira/browse/HDFS-16664?focusedWorklogId=792165&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-792165
]
ASF GitHub Bot logged work on HDFS-16664:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 18/Jul/22 14:42
Start Date: 18/Jul/22 14:42
Worklog Time Spent: 10m
Work Description: KevinWikant commented on PR #4568:
URL: https://github.com/apache/hadoop/pull/4568#issuecomment-1187587395
Yetus failing because no new unit test was added:
```
The patch doesn't appear to include any new or modified tests. Please
justify why no new tests are needed for this patch. Also please list what
manual steps were performed to verify this patch.
```
Note that this change was unit tested via the existing test
"TestDecommission#testDeleteCorruptReplicaForUnderReplicatedBlock", the only
caveat is that this unit test is behaving differently when backporting
[HDFS-16064](https://issues.apache.org/jira/browse/HDFS-16064) to older Hadoop
versions, which is what caused this bug to be discovered in the first place.
See the section "Why does unit test failure not reproduce in Hadoop trunk?"
in [HDFS-16664](https://issues.apache.org/jira/browse/HDFS-16664) for
additional details on difference in behavior. In summary:
- on trunk the corrupt block replicas are invalidated immediately when first
block report is sent
- on branch-3.2.1 the corrupt block replica invalidation is getting
postponed for some reason
Need additional time to investigate this difference in behavior, if possible
I will try to make the unit test behavior more consistent
Can also add some unit testing to new code in CorruptReplicasMap
Issue Time Tracking
-------------------
Worklog Id: (was: 792165)
Time Spent: 50m (was: 40m)
> Use correct GenerationStamp when invalidating corrupt block replicas
> --------------------------------------------------------------------
>
> Key: HDFS-16664
> URL: https://issues.apache.org/jira/browse/HDFS-16664
> Project: Hadoop HDFS
> Issue Type: Bug
> Reporter: Kevin Wikant
> Priority: Major
> Labels: pull-request-available
> Time Spent: 50m
> Remaining Estimate: 0h
>
> While trying to backport HDFS-16064 to an older Hadoop version, the new unit
> test "testDeleteCorruptReplicaForUnderReplicatedBlock" started failing
> unexpectedly.
> Upon deep diving this unit test failure, I identified a bug in HDFS corrupt
> replica invalidation which results in the following datanode exception:
> {quote}2022-07-16 08:07:52,041 [BP-958471676-X-1657973243350 heartbeating to
> localhost/127.0.0.1:61365] WARN datanode.DataNode
> (BPServiceActor.java:processCommand(887)) - Error processing datanode Command
> java.io.IOException: Failed to delete 1 (out of 1) replica(s):
> 0) Failed to delete replica blk_1073741825_1005: GenerationStamp not matched,
> existing replica is blk_1073741825_1001
> at
> org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetImpl.invalidate(FsDatasetImpl.java:2139)
> at
> org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetImpl.invalidate(FsDatasetImpl.java:2034)
> at
> org.apache.hadoop.hdfs.server.datanode.BPOfferService.processCommandFromActive(BPOfferService.java:735)
> at
> org.apache.hadoop.hdfs.server.datanode.BPOfferService.processCommandFromActor(BPOfferService.java:680)
> at
> org.apache.hadoop.hdfs.server.datanode.BPServiceActor.processCommand(BPServiceActor.java:883)
> at
> org.apache.hadoop.hdfs.server.datanode.BPServiceActor.offerService(BPServiceActor.java:678)
> at
> org.apache.hadoop.hdfs.server.datanode.BPServiceActor.run(BPServiceActor.java:849)
> at java.lang.Thread.run(Thread.java:750)
> {quote}
> The issue is that the Namenode is sending wrong generationStamp to the
> datanode. By adding some additional logs, I was able to determine the root
> cause for this:
> * the generationStamp sent in the DNA_INVALIDATE is based on the
> [generationStamp of the block sent in the block
> report|https://github.com/apache/hadoop/blob/8774f178686487007dcf8c418c989b785a529000/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java#L3733]
> * the problem is that the datanode with the corrupt block replica (that
> receives the DNA_INVALIDATE) is not necissarily the same datanode that sent
> the block report
> * this can cause the above exception when the corrupt block replica on the
> datanode receiving the DNA_INVALIDATE & the block replica on the datanode
> that sent the block report have different generationStamps
> The solution is to store the corrupt replicas generationStamp in the
> CorruptReplicasMap, then to extract this correct generationStamp value when
> sending the DNA_INVALIDATE to the datanode
>
> h2. Failed Test - Before the fix
> {quote}> mvn test
> -Dtest=TestDecommission#testDeleteCorruptReplicaForUnderReplicatedBlock
>
> [INFO] Results:
> [INFO]
> [ERROR] Failures:
> [ERROR]
> TestDecommission.testDeleteCorruptReplicaForUnderReplicatedBlock:2035 Node
> 127.0.0.1:61366 failed to complete decommissioning. numTrackedNodes=1 ,
> numPendingNodes=0 , adminState=Decommission In Progress ,
> nodesWithReplica=[127.0.0.1:61366, 127.0.0.1:61419]
> {quote}
> Logs:
> {quote}> cat
> target/surefire-reports/org.apache.hadoop.hdfs.TestDecommission-output.txt |
> grep 'Expected Replicas:|XXX|FINALIZED|Block now|Failed to delete'
> 2022-07-16 08:07:45,891 [Listener at localhost/61378] INFO
> hdfs.TestDecommission
> (TestDecommission.java:testDeleteCorruptReplicaForUnderReplicatedBlock(1942))
> - Block now has 2 corrupt replicas on [127.0.0.1:61370 , 127.0.0.1:61375] and
> 1 live replica on 127.0.0.1:61366
> 2022-07-16 08:07:45,913 [Listener at localhost/61378] INFO
> hdfs.TestDecommission
> (TestDecommission.java:testDeleteCorruptReplicaForUnderReplicatedBlock(1974))
> - Block now has 2 corrupt replicas on [127.0.0.1:61370 , 127.0.0.1:61375] and
> 1 decommissioning replica on 127.0.0.1:61366
> XXX invalidateBlock dn=127.0.0.1:61415 , blk=1073741825_1001
> XXX postponeBlock dn=127.0.0.1:61415 , blk=1073741825_1001
> XXX invalidateBlock dn=127.0.0.1:61419 , blk=1073741825_1003
> XXX addToInvalidates dn=127.0.0.1:61419 , blk=1073741825_1003
> XXX addBlocksToBeInvalidated dn=127.0.0.1:61419 , blk=1073741825_1003
> XXX rescanPostponedMisreplicatedBlocks blk=1073741825_1005
> XXX DNA_INVALIDATE dn=/127.0.0.1:61419 , blk=1073741825_1003
> XXX invalidate(on DN) dn=/127.0.0.1:61419 , invalidBlk=blk_1073741825_1003 ,
> blkByIdAndGenStamp = FinalizedReplica, blk_1073741825_1003, FINALIZED
> 2022-07-16 08:07:49,084 [BP-958471676-X-1657973243350 heartbeating to
> localhost/127.0.0.1:61365] INFO impl.FsDatasetAsyncDiskService
> (FsDatasetAsyncDiskService.java:deleteAsync(226)) - Scheduling
> blk_1073741825_1003 replica FinalizedReplica, blk_1073741825_1003, FINALIZED
> XXX addBlock dn=127.0.0.1:61419 , blk=1073741825_1005 *<<< block report is
> coming from 127.0.0.1:61419 which has genStamp=1005*
> XXX invalidateCorruptReplicas dn=127.0.0.1:61415 ,
> reported_blk=1073741825_1005 *<<< corrupt replica is on 127.0.0.1:61415
> which is expecting genStamp=1001*
> XXX addToInvalidates dn=127.0.0.1:61415 , blk=1073741825_1005
> 2022-07-16 08:07:49,431 [DatanodeAdminMonitor-0] INFO BlockStateChange
> (DatanodeAdminManager.java:logBlockReplicationInfo(417)) - Block:
> blk_1073741825_1005, Expected Replicas: 2, live replicas: 1, corrupt
> replicas: 0, decommissioned replicas: 0, decommissioning replicas: 1,
> maintenance replicas: 0, live entering maintenance replicas: 0, excess
> replicas: 0, Is Open File: false, Datanodes having this block:
> 127.0.0.1:61366 127.0.0.1:61419 , Current Datanode: 127.0.0.1:61366, Is
> current datanode decommissioning: true, Is current datanode entering
> maintenance: false
> XXX addBlocksToBeInvalidated dn=127.0.0.1:61415 , blk=1073741825_1005 *<<<
> Namenode sends wrong genStamp to 127.0.0.1:61415*
> XXX DNA_INVALIDATE dn=/127.0.0.1:61415 , blk=1073741825_1005
> XXX invalidate(on DN) dn=/127.0.0.1:61415 , invalidBlk=blk_1073741825_1005 ,
> blkByIdAndGenStamp = null
> XXX invalidate(on DN) dn=/127.0.0.1:61415 , invalidBlk=blk_1073741825_1005 ,
> blkById = FinalizedReplica, blk_1073741825_1001, FINALIZED
> 2022-07-16 08:07:52,041 [BP-958471676-X-1657973243350 heartbeating to
> localhost/127.0.0.1:61365] WARN datanode.DataNode
> (BPServiceActor.java:processCommand(887)) - Error processing datanode Command
> java.io.IOException: Failed to delete 1 (out of 1) replica(s):
> 0) Failed to delete replica blk_1073741825_1005: GenerationStamp not matched,
> existing replica is blk_1073741825_1001
> at
> org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetImpl.invalidate(FsDatasetImpl.java:2139)
> at
> org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetImpl.invalidate(FsDatasetImpl.java:2034)
> at
> org.apache.hadoop.hdfs.server.datanode.BPOfferService.processCommandFromActive(BPOfferService.java:735)
> at
> org.apache.hadoop.hdfs.server.datanode.BPOfferService.processCommandFromActor(BPOfferService.java:680)
> at
> org.apache.hadoop.hdfs.server.datanode.BPServiceActor.processCommand(BPServiceActor.java:883)
> at
> org.apache.hadoop.hdfs.server.datanode.BPServiceActor.offerService(BPServiceActor.java:678)
> at
> org.apache.hadoop.hdfs.server.datanode.BPServiceActor.run(BPServiceActor.java:849)
> at java.lang.Thread.run(Thread.java:750)
> 2022-07-16 08:07:52,384 [DataXceiver for client at /127.0.0.1:61434
> [Receiving block BP-958471676-X-1657973243350:blk_1073741825_1005]] INFO
> datanode.DataNode (DataXceiver.java:writeBlock(939)) - opWriteBlock
> BP-958471676-X-1657973243350:blk_1073741825_1005 received exception
> org.apache.hadoop.hdfs.server.datanode.ReplicaAlreadyExistsException: Block
> BP-958471676-X-1657973243350:blk_1073741825_1005 already exists in state
> FINALIZED and thus cannot be created.
> 2022-07-16 08:07:52,385 [DataXceiver for client at /127.0.0.1:61434
> [Receiving block BP-958471676-X-1657973243350:blk_1073741825_1005]] INFO
> datanode.DataNode (DataXceiver.java:run(307)) - 127.0.0.1:61415:DataXceiver
> error processing WRITE_BLOCK operation src: /127.0.0.1:61434 dst:
> /127.0.0.1:61415;
> org.apache.hadoop.hdfs.server.datanode.ReplicaAlreadyExistsException: Block
> BP-958471676-X-1657973243350:blk_1073741825_1005 already exists in state
> FINALIZED and thus cannot be created.
> 2022-07-16 08:07:54,422 [DatanodeAdminMonitor-0] INFO BlockStateChange
> (DatanodeAdminManager.java:logBlockReplicationInfo(417)) - Block:
> blk_1073741825_1005, Expected Replicas: 2, live replicas: 1, corrupt
> replicas: 0, decommissioned replicas: 0, decommissioning replicas: 1,
> maintenance replicas: 0, live entering maintenance replicas: 0, excess
> replicas: 0, Is Open File: false, Datanodes having this block:
> 127.0.0.1:61366 127.0.0.1:61419 , Current Datanode: 127.0.0.1:61366, Is
> current datanode decommissioning: true, Is current datanode entering
> maintenance: false
> ...
> 2022-07-16 08:08:24,426 [DatanodeAdminMonitor-0] INFO BlockStateChange
> (DatanodeAdminManager.java:logBlockReplicationInfo(417)) - Block:
> blk_1073741825_1005, Expected Replicas: 2, live replicas: 1, corrupt
> replicas: 0, decommissioned replicas: 0, decommissioning replicas: 1,
> maintenance replicas: 0, live entering maintenance replicas: 0, excess
> replicas: 0, Is Open File: false, Datanodes having this block:
> 127.0.0.1:61366 127.0.0.1:61419 , Current Datanode: 127.0.0.1:61366, Is
> current datanode decommissioning: true, Is current datanode entering
> maintenance: false
> {quote}
> Note the inline comments above which illustrate the bug
> h2. Successful Test - After the fix
> {quote}> mvn test
> -Dtest=TestDecommission#testDeleteCorruptReplicaForUnderReplicatedBlock
> [INFO] Results:
> [INFO]
> [INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0
> {quote}
> Logs:
> {quote}> cat
> target/surefire-reports/org.apache.hadoop.hdfs.TestDecommission-output.txt |
> grep 'Expected Replicas:|XXX|FINALIZED|Block now|Failed to delete'
> 2022-07-16 07:54:30,648 [Listener at localhost/60376] INFO
> hdfs.TestDecommission
> (TestDecommission.java:testDeleteCorruptReplicaForUnderReplicatedBlock(1942))
> - Block now has 2 corrupt replicas on [127.0.0.1:60364 , 127.0.0.1:60368] and
> 1 live replica on 127.0.0.1:60373
> 2022-07-16 07:54:30,669 [Listener at localhost/60376] INFO
> hdfs.TestDecommission
> (TestDecommission.java:testDeleteCorruptReplicaForUnderReplicatedBlock(1974))
> - Block now has 2 corrupt replicas on [127.0.0.1:60364 , 127.0.0.1:60368] and
> 1 decommissioning replica on 127.0.0.1:60373
> XXX invalidateBlock dn=127.0.0.1:60423 , blk=1073741825_1001
> XXX postponeBlock dn=127.0.0.1:60423 , blk=1073741825_1001
> XXX invalidateBlock dn=127.0.0.1:60427 , blk=1073741825_1003
> XXX addToInvalidates dn=127.0.0.1:60427 , blk=1073741825_1003
> XXX addBlocksToBeInvalidated dn=127.0.0.1:60427 , blk=1073741825_1003
> XXX rescanPostponedMisreplicatedBlocks blk=1073741825_1005
> XXX DNA_INVALIDATE dn=/127.0.0.1:60427 , blk=1073741825_1003
> XXX invalidate(on DN) dn=/127.0.0.1:60427 , invalidBlk=blk_1073741825_1003 ,
> blkByIdAndGenStamp = FinalizedReplica, blk_1073741825_1003, FINALIZED
> 2022-07-16 07:54:32,831 [BP-1469857843-X-1657972447604 heartbeating to
> localhost/127.0.0.1:60363] INFO impl.FsDatasetAsyncDiskService
> (FsDatasetAsyncDiskService.java:deleteAsync(226)) - Scheduling
> blk_1073741825_1003 replica FinalizedReplica, blk_1073741825_1003, FINALIZED
> 2022-07-16 07:54:33,772 [DatanodeAdminMonitor-0] INFO BlockStateChange
> (DatanodeAdminManager.java:logBlockReplicationInfo(417)) - Block:
> blk_1073741825_1005, Expected Replicas: 2, live replicas: 0, corrupt
> replicas: 1, decommissioned replicas: 0, decommissioning replicas: 1,
> maintenance replicas: 0, live entering maintenance replicas: 0, excess
> replicas: 0, Is Open File: false, Datanodes having this block:
> 127.0.0.1:60373 127.0.0.1:60423 , Current Datanode: 127.0.0.1:60373, Is
> current datanode decommissioning: true, Is current datanode entering
> maintenance: false
> XXX addBlock dn=127.0.0.1:60427 , blk=1073741825_1005
> XXX invalidateCorruptReplicas dn=127.0.0.1:60423 ,
> reported_blk=1073741825_1005
> XXX getCorruptReplicaGenerationStamp dn=127.0.0.1:60423 , genStamp=1001
> XXX addToInvalidates dn=127.0.0.1:60423 , blk=1073741825_1001
> XXX addBlocksToBeInvalidated dn=127.0.0.1:60423 , blk=1073741825_1001
> XXX DNA_INVALIDATE dn=/127.0.0.1:60423 , blk=1073741825_1001
> XXX invalidate(on DN) dn=/127.0.0.1:60423 , invalidBlk=blk_1073741825_1001 ,
> blkByIdAndGenStamp = FinalizedReplica, blk_1073741825_1001, FINALIZED
> 2022-07-16 07:54:35,796 [BP-1469857843-X-1657972447604 heartbeating to
> localhost/127.0.0.1:60363] INFO impl.FsDatasetAsyncDiskService
> (FsDatasetAsyncDiskService.java:deleteAsync(226)) - Scheduling
> blk_1073741825_1001 replica FinalizedReplica, blk_1073741825_1001, FINALIZED
> XXX addBlock dn=127.0.0.1:60423 , blk=1073741825_1005
> 2022-07-16 07:54:40,768 [Listener at localhost/60430] INFO
> hdfs.TestDecommission
> (TestDecommission.java:testDeleteCorruptReplicaForUnderReplicatedBlock(2050))
> - Block now has 2 live replicas on [127.0.0.1:60423 , 127.0.0.1:60427] and 1
> decommissioned replica on 127.0.0.1:60373
> {quote}
> Using "getCorruptReplicaGenerationStamp" allows the Namenode to get the
> correct generationStamp for the corrupt block replica
>
> h2. Why does unit test failure not reproduce in Hadoop trunk?
> In trunk the block invalidation does not get [postponed
> here|https://github.com/apache/hadoop/blob/8774f178686487007dcf8c418c989b785a529000/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java#L1986]
> Instead, both corrupt replicas are invalidated immediately during the first
> block report:
> {quote}> cat
> target/surefire-reports/org.apache.hadoop.hdfs.TestDecommission-output.txt |
> grep XXX
> XXX addToInvalidates dn=127.0.0.1:57051 , blk=1073741825_1001
> XXX addToInvalidates dn=127.0.0.1:57055 , blk=1073741825_1003
> {quote}
> The reason for this difference in behavior is not clear at this point
> h2. Additional Info
> * stack trace for when corrupt replica gets immediately invalidated on
> datanode restart (i.e. first block report)
>
> {quote}java.lang.Thread.getStackTrace(Thread.java:1564)
> org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.addToInvalidates(BlockManager.java:1670)
> org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.invalidateBlock(BlockManager.java:1850)
> org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.markBlockAsCorrupt(BlockManager.java:1816)
> org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.processFirstBlockReport(BlockManager.java:2929)
> org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.processReport(BlockManager.java:2665)
> org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.lambda$blockReport$0(NameNodeRpcServer.java:1588)
> java.util.concurrent.FutureTask.run(FutureTask.java:266)
> org.apache.hadoop.hdfs.server.blockmanagement.BlockManager$BlockReportProcessingThread.processQueue(BlockManager.java:5066)
> org.apache.hadoop.hdfs.server.blockmanagement.BlockManager$BlockReportProcessingThread.run(BlockManager.java:5045)
> {quote}
>
> * stack trace for after corrupt replica is removed from datanode & datanode
> notifies namenode (i.e. incremental block report)
> ** this is where the issue begins because the DN which sends the IBR is not
> the same as the DN with the remaining corrupt replica
> {quote}java.lang.Thread.getStackTrace(Thread.java:1564)
> org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.addToInvalidates(BlockManager.java:1670)
> org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.invalidateBlock(BlockManager.java:1850)
> org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.invalidateCorruptReplicas(BlockManager.java:3477)
> org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.addStoredBlock(BlockManager.java:3436)
> org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.processAndHandleReportedBlock(BlockManager.java:4094)
> org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.addBlock(BlockManager.java:4023)
> org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.processIncrementalBlockReport(BlockManager.java:4151)
> org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.processIncrementalBlockReport(BlockManager.java:4118)
> org.apache.hadoop.hdfs.server.namenode.FSNamesystem.processIncrementalBlockReport(FSNamesystem.java:4800)
> org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer$1.run(NameNodeRpcServer.java:1643)
> org.apache.hadoop.hdfs.server.blockmanagement.BlockManager$BlockReportProcessingThread.processQueue(BlockManager.java:5066)
> org.apache.hadoop.hdfs.server.blockmanagement.BlockManager$BlockReportProcessingThread.run(BlockManager.java:5045)
> {quote}
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