[jira] Commented: (HADOOP-1188) processIOError() should update fstime file

["dhruba borthakur (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HADOOP-1188?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12553528 ] 

dhruba borthakur commented on HADOOP-1188:
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It is possible that updating the fstime on the good directories could fail too. So, a namenode restart should pick all those directories that have the latest (and same) fstime and fail to restart if the sizes of the edit files in those directories are not exactly the same.

> processIOError() should update fstime file
> ------------------------------------------
>
>                 Key: HADOOP-1188
>                 URL: https://issues.apache.org/jira/browse/HADOOP-1188
>             Project: Hadoop
>          Issue Type: Bug
>          Components: dfs
>    Affects Versions: 0.10.1, 0.11.2, 0.12.2
>            Reporter: Konstantin Shvachko
>
> Name-node can have multiple directories to store the name space image and edits.
> During startup the name-node selects the latest image and reads it in memory.
> fstime stores the time of the latest checkpoint.
> If one of the directories becomes inaccessible during normal operation the name-node
> excludes it from the list, and never writes anything into it until restarted.
> Now if the the name-node restarts after excluding one of the directories, and if that
> excluded directory contained the latest image, then all modifications of the name space
> recorded in edits files in other directories starting from the moment the directory was
> excluded will be lost.
> We should update fstime in all remaining good directories after the exclusion.

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