[
https://issues.apache.org/jira/browse/HDFS-11179?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15703169#comment-15703169
]
Wei-Chiu Chuang commented on HDFS-11179:
----------------------------------------
[~tasanuma0829] thanks for filing the bug report.
While I think this fix is important, I don't see why it's a blocker.
For reference, we've seen block id overflow in the past in logs, but we've not
noticed it caused real issues.
> LightWeightHashSet can't remove blocks correctly which have a large number
> blockId
> ----------------------------------------------------------------------------------
>
> Key: HDFS-11179
> URL: https://issues.apache.org/jira/browse/HDFS-11179
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: namenode
> Affects Versions: 3.0.0-alpha1
> Reporter: Takanobu Asanuma
> Assignee: Takanobu Asanuma
> Priority: Blocker
>
> Our test cluster has faced a problem that
> {{postponedMisreplicatedBlocksCount}} has been going below zero. The version
> of the cluster is a recent 3.0. We haven't created any EC files yet. This is
> the NN's log:
> {noformat}
> Rescan of postponedMisreplicatedBlocks completed in 13 msecs. 448 blocks are
> left. 176 blocks are removed.
> Rescan of postponedMisreplicatedBlocks completed in 13 msecs. 272 blocks are
> left. 176 blocks are removed.
> Rescan of postponedMisreplicatedBlocks completed in 14 msecs. 96 blocks are
> left. 176 blocks are removed.
> Rescan of postponedMisreplicatedBlocks completed in 327 msecs. -77 blocks are
> left. 177 blocks are removed.
> Rescan of postponedMisreplicatedBlocks completed in 15 msecs. -253 blocks are
> left. 179 blocks are removed.
> Rescan of postponedMisreplicatedBlocks completed in 14 msecs. -432 blocks are
> left. 179 blocks are removed.
> {noformat}
> I looked into this issue and found that it is caused by
> {{LightWeightHashSet}} which is used for {{postponedMisreplicatedBlocks}}
> recently. When {{LightWeightHashSet}} remove blocks which have a large number
> blockId, overflows happen and the blocks can't be removed correctly(, let
> alone ec blocks whose blockId starts with the minimum of long).
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
