[
https://issues.apache.org/jira/browse/HDFS-8827?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Takuya Fukudome updated HDFS-8827:
----------------------------------
Attachment: HDFS-8827.1.patch
Thanks for the comment, [~zhz]! I attached an initial patch which added a unit
test occurs this issue. It processes a small EC file which doesn't have full
internal blocks and its internal blocks are over replicated.
If I understood correctly, when some indices of internal blocks are missing and
internal blocks are over replicated,
{{BlockPlacementPolicyDefault#chooseReplicaToDelete}} will return null. I think
the cause is the {{excessTypes}} in {{chooseExcessReplicasStriped}} is empty
during the process of such blocks.
> Erasure Coding: When namenode processes over replicated striped block, NPE
> will be occur in ReplicationMonitor
> --------------------------------------------------------------------------------------------------------------
>
> Key: HDFS-8827
> URL: https://issues.apache.org/jira/browse/HDFS-8827
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Reporter: Takuya Fukudome
> Assignee: Takuya Fukudome
> Attachments: HDFS-8827.1.patch, processing-over-replica-npe.log
>
>
> In our test cluster, when namenode processed over replicated striped blocks,
> null pointer exception(NPE) occurred. This happened under below situation: 1)
> some datanodes shutdown. 2) namenode recovers block group which lost internal
> blocks. 3) restart the stopped datanodes. 4) namenode processes over
> replicated striped blocks. 5) NPE occurs
> I think BlockPlacementPolicyDefault#chooseReplicaToDelete will return null in
> this situation which causes this NPE problem.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
