[jira] [Resolved] (HDFS-3122) Block recovery with closeFile flag true can race with blockReport. Due to this blocks are getting marked as corrupt.

["Mit Desai (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HDFS-3122?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Mit Desai resolved HDFS-3122.
-----------------------------

          Resolution: Not a Problem
    Target Version/s: 0.23.3, 0.24.0  (was: 0.24.0, 0.23.3)

Haven't heard anything yet. Resolving this issue. Feel free to reopen if anyone thinks the other way.

> Block recovery with closeFile flag true can race with blockReport. Due to this blocks are getting marked as corrupt.
> --------------------------------------------------------------------------------------------------------------------
>
>                 Key: HDFS-3122
>                 URL: https://issues.apache.org/jira/browse/HDFS-3122
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: datanode, namenode
>    Affects Versions: 0.23.0, 0.24.0
>            Reporter: Uma Maheswara Rao G
>            Assignee: Uma Maheswara Rao G
>            Priority: Critical
>         Attachments: blockCorrupt.txt
>
>
> *Block Report* can *race* with *Block Recovery* with closeFile flag true.
>  Block report generated just before block recovery at DN side and due to N/W problems, block report got delayed to NN. 
> After this, recovery success and generation stamp modifies to new one. 
> And primary DN invokes the commitBlockSynchronization and block got updated in NN side. Also block got marked as complete, since the closeFile flag was true. Updated with new genstamp.
> Now blockReport started processing at NN side. This particular block from RBW (when it generated the BR at DN), and file was completed at NN side.
> Finally block will be marked as corrupt because of genstamp mismatch.
> {code}
>  case RWR:
>       if (!storedBlock.isComplete()) {
>         return null; // not corrupt
>       } else if (storedBlock.getGenerationStamp() != iblk.getGenerationStamp()) {
>         return new BlockToMarkCorrupt(storedBlock,
>             "reported " + reportedState + " replica with genstamp " +
>             iblk.getGenerationStamp() + " does not match COMPLETE block's " +
>             "genstamp in block map " + storedBlock.getGenerationStamp());
>       } else { // COMPLETE block, same genstamp
> {code}



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