hadoop-hdfs-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Hairong Kuang (JIRA)" <j...@apache.org>
Subject [jira] Resolved: (HDFS-86) Corrupted blocks get deleted but not replicated
Date Thu, 19 Aug 2010 16:58:18 GMT

     [ https://issues.apache.org/jira/browse/HDFS-86?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel

Hairong Kuang resolved HDFS-86.

    Resolution: Invalid

> Corrupted blocks get deleted but not replicated
> -----------------------------------------------
>                 Key: HDFS-86
>                 URL: https://issues.apache.org/jira/browse/HDFS-86
>             Project: Hadoop HDFS
>          Issue Type: Bug
>            Reporter: Hairong Kuang
>            Assignee: Hairong Kuang
>         Attachments: blockInvalidate.patch
> When I test the patch to HADOOP-1345 on a two node dfs cluster, I see that dfs correctly
delete the corrupted replica and successfully retry reading from the other correct replica,
but the block does not get replicated. The block remains with only 1 replica until the next
block report comes in.
> In my testcase, since the dfs cluster has only 2 datanodes, the target of replication
is the same as the target of block invalidation.  After poking the logs, I found out that
the namenode sent the replication request before the block invalidation request. 
> This is because the namenode does not invalidate a block well. In FSNamesystem.invalidateBlock,
it first puts the invalidate request in a queue and then immediately removes the replica from
its state, which triggers the choosing a target for the block. When requests are sent back
to the target datanode as a reply to a heartbeat message, the replication requests have higher
priority than the invalidate requests.
> This problem could be solved if a namenode removes an invalidated replica from its state
only after the invalidate request is sent to the datanode.

This message is automatically generated by JIRA.
You can reply to this email to add a comment to the issue online.

View raw message