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Posted to issues@ozone.apache.org by "Siyao Meng (Jira)" <ji...@apache.org> on 2023/08/09 21:49:00 UTC

[jira] [Created] (HDDS-9146) Potential data loss with HSync

Siyao Meng created HDDS-9146:
--------------------------------

             Summary: Potential data loss with HSync
                 Key: HDDS-9146
                 URL: https://issues.apache.org/jira/browse/HDDS-9146
             Project: Apache Ozone
          Issue Type: Bug
            Reporter: Siyao Meng


It is observed that when {{hsync()}} is called followed by a {{close()}} for a key stream (which triggers two {{OMKeyCommitRequest}}, the first one with {{isHSync = true}} and the second one with {{isHSync = false}}), {{deletedTable}} could have an entry with the exact same block containerId and locId, which can cause OM's {{KeyDeletingService}} to remove the committed block by mistake. causing data loss when the container is closed, after which block deletion will then actually happen on DNs.

Repro integration test branch (based on [~erose]'s integration test in turn based on my initial draft):


{code:title=Test log. See entry in keyTable and deletedTable has the same block conID: 1 and locID: 111677748019200001}
2023-08-09 14:31:54,859 [main] WARN  ozone.TestMiniOzoneCluster (TestMiniOzoneCluster.java:testKeyRenameDirDelete(159)) - keyTable:     ----- START -----
2023-08-09 14:31:54,860 [main] WARN  ozone.TestMiniOzoneCluster (TestMiniOzoneCluster.java:testKeyRenameDirDelete(168)) - keyTable:     key = /testozonevol/testozonebucket/inputTera/_temporary/1/_temporary/attempt_1691047336995_0006_m_000001_0/part-m-00001, val = OmKeyInfo{volumeName='testozonevol', bucketName='testozonebucket', keyName='inputTera/_temporary/1/_temporary/attempt_1691047336995_0006_m_000001_0/part-m-00001', dataSize=11, keyLocationVersions=[OmKeyLocationInfoGroup{version=0, locationVersionMap={0=[{blockID={conID: 1 locID: 111677748019200001 bcsId: 2}, length=11, offset=0, token=null, pipeline=null, createVersion=0, partNumber=0}]}, isMultipartKey=false}], creationTime=1691616714661, modificationTime=1691616714848, replicationConfig=RATIS/THREE, encInfo=null, fileChecksum=null, isFile=true, fileName='part-m-00001'}
2023-08-09 14:31:54,860 [main] WARN  ozone.TestMiniOzoneCluster (TestMiniOzoneCluster.java:testKeyRenameDirDelete(171)) - keyTable:     -----  END  -----
2023-08-09 14:31:54,860 [main] WARN  ozone.TestMiniOzoneCluster (TestMiniOzoneCluster.java:testKeyRenameDirDelete(173)) - deletedTable: ----- START -----
2023-08-09 14:31:54,861 [main] WARN  ozone.TestMiniOzoneCluster (TestMiniOzoneCluster.java:testKeyRenameDirDelete(181)) - deletedTable: key = /testozonevol/testozonebucket/inputTera/_temporary/1/_temporary/attempt_1691047336995_0006_m_000001_0/part-m-00001/-9223372036854774528, val = RepeatedOmKeyInfo{omKeyInfoList=[OmKeyInfo{volumeName='testozonevol', bucketName='testozonebucket', keyName='inputTera/_temporary/1/_temporary/attempt_1691047336995_0006_m_000001_0/part-m-00001', dataSize=11, keyLocationVersions=[OmKeyLocationInfoGroup{version=0, locationVersionMap={0=[{blockID={conID: 1 locID: 111677748019200001 bcsId: 0}, length=11, offset=0, token=null, pipeline=null, createVersion=0, partNumber=0}]}, isMultipartKey=false}], creationTime=1691616714661, modificationTime=1691616714834, replicationConfig=RATIS/THREE, encInfo=null, fileChecksum=null, isFile=true, fileName='part-m-00001'}]}
2023-08-09 14:31:54,861 [main] WARN  ozone.TestMiniOzoneCluster (TestMiniOzoneCluster.java:testKeyRenameDirDelete(184)) - deletedTable: -----  END  -----
{code}

Sounds to me the fix should be to filter out any block that shares the same containerId and locId when adding entry into deletedTable inside OMKeyCommitRequest / OMKeyCommitRequestWithFSO. But I'm no expert in HSync so please advise. cc [~weichiu] [~szetszwo]



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