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https://issues.apache.org/jira/browse/HDFS-7587?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14277943#comment-14277943
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Tsz Wo Nicholas Sze commented on HDFS-7587:
-------------------------------------------
{code}
+ // MUST attempt quota update before changing in-memory states
+ updateQuotaForAppend(iip, file);
...
+ // may fail if block token creation fails, but we're still in a
+ // consistent state if the edit is logged first
+ return blockManager.convertLastBlockToUnderConstruction(file, 0);
{code}
I think we should use FSDirectory.verifyQuota(..) (instead updating quote) in
the beginning and then update quota at the end. Otherwise, the quote counts
will be incorrect if there is an exception thrown later on.
> Edit log corruption can happen if append fails with a quota violation
> ---------------------------------------------------------------------
>
> Key: HDFS-7587
> URL: https://issues.apache.org/jira/browse/HDFS-7587
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: namenode
> Reporter: Kihwal Lee
> Assignee: Daryn Sharp
> Priority: Blocker
> Attachments: HDFS-7587.patch
>
>
> We have seen a standby namenode crashing due to edit log corruption. It was
> complaining that {{OP_CLOSE}} cannot be applied because the file is not
> under-construction.
> When a client was trying to append to the file, the remaining space quota was
> very small. This caused a failure in {{prepareFileForWrite()}}, but after the
> inode was already converted for writing and a lease added. Since these were
> not undone when the quota violation was detected, the file was left in
> under-construction with an active lease without edit logging {{OP_ADD}}.
> A subsequent {{append()}} eventually caused a lease recovery after the soft
> limit period. This resulted in {{commitBlockSynchronization()}}, which closed
> the file with {{OP_CLOSE}} being logged. Since there was no corresponding
> {{OP_ADD}}, edit replaying could not apply this.
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