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https://issues.apache.org/jira/browse/HDFS-11160?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15753099#comment-15753099
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Hudson commented on HDFS-11160:
-------------------------------

SUCCESS: Integrated in Jenkins build Hadoop-trunk-Commit #11006 (See 
[https://builds.apache.org/job/Hadoop-trunk-Commit/11006/])
HDFS-11160. VolumeScanner reports write-in-progress replicas as corrupt 
(weichiu: rev aebb9127bae872835d057e1c6a6e6b3c6a8be6cd)
* (edit) 
hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/FinalizedReplica.java
* (edit) 
hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestBlockScanner.java
* (edit) 
hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/FsVolumeSpi.java
* (edit) 
hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDirectoryScanner.java
* (edit) 
hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/VolumeScanner.java
* (edit) 
hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BlockSender.java
* (edit) 
hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/extdataset/ExternalVolumeImpl.java
* (edit) 
hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsVolumeImpl.java
* (edit) 
hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/SimulatedFSDataset.java
* (edit) 
hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BlockScanner.java


> VolumeScanner reports write-in-progress replicas as corrupt incorrectly
> -----------------------------------------------------------------------
>
>                 Key: HDFS-11160
>                 URL: https://issues.apache.org/jira/browse/HDFS-11160
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: datanode
>         Environment: CDH5.7.4
>            Reporter: Wei-Chiu Chuang
>            Assignee: Wei-Chiu Chuang
>         Attachments: HDFS-11160.001.patch, HDFS-11160.002.patch, 
> HDFS-11160.003.patch, HDFS-11160.004.patch, HDFS-11160.005.patch, 
> HDFS-11160.006.patch, HDFS-11160.007.patch, HDFS-11160.008.patch, 
> HDFS-11160.branch-2.patch, HDFS-11160.reproduce.patch
>
>
> Due to a race condition initially reported in HDFS-6804, VolumeScanner may 
> erroneously detect good replicas as corrupt. This is serious because in some 
> cases it results in data loss if all replicas are declared corrupt. This bug 
> is especially prominent when there are a lot of append requests via 
> HttpFs/WebHDFS.
> We are investigating an incidence that caused very high block corruption rate 
> in a relatively small cluster. Initially, we thought HDFS-11056 is to blame. 
> However, after applying HDFS-11056, we are still seeing VolumeScanner 
> reporting corrupt replicas.
> It turns out that if a replica is being appended while VolumeScanner is 
> scanning it, VolumeScanner may use the new checksum to compare against old 
> data, causing checksum mismatch.
> I have a unit test to reproduce the error. Will attach later. A quick and 
> simple fix is to hold FsDatasetImpl lock and read from disk the checksum.



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