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https://issues.apache.org/jira/browse/HDFS-6527?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14031114#comment-14031114
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Kihwal Lee commented on HDFS-6527:
----------------------------------
Thanks for the comment, [~jingzhao]. We can null out the client name while
deleting files. Then lease check is guaranteed to fail.
In {{INodeFile#destroyAndCollectBlocks()}}, we can delete the client name.
{code}
if (sf != null) {
sf.clearDiffs();
}
+
+ // Delete client name if under construction. This destroys a half of
+ // the lease. The other half will be removed later from LeaseManager.
+ FileUnderConstructionFeature uc = getFileUnderConstructionFeature();
+ if (uc != null) {
+ uc.setClientName(null);
+ }
}
{code}
And in {{FSNamesystem#checkLease()}}, we can have the following check instead
of the parent == null check.
{code}
String clientName = file.getFileUnderConstructionFeature().getClientName();
+ if (clientName == null) {
+ // clientName is removed when the file is deleted.
+ throw new FileNotFoundException(src);
+ }
{code}
This will make lease checks to fail once the "real" file is deleted, whether it
is in a snapshot or not. Do you think it is reasonable?
> Edit log corruption due to defered INode removal
> ------------------------------------------------
>
> Key: HDFS-6527
> URL: https://issues.apache.org/jira/browse/HDFS-6527
> Project: Hadoop HDFS
> Issue Type: Bug
> Affects Versions: 2.4.0
> Reporter: Kihwal Lee
> Assignee: Kihwal Lee
> Priority: Blocker
> Attachments: HDFS-6527.branch-2.4.patch, HDFS-6527.trunk.patch,
> HDFS-6527.v2.patch
>
>
> We have seen a SBN crashing with the following error:
> {panel}
> \[Edit log tailer\] ERROR namenode.FSEditLogLoader:
> Encountered exception on operation AddBlockOp
> [path=/xxx,
> penultimateBlock=NULL, lastBlock=blk_111_111, RpcClientId=,
> RpcCallId=-2]
> java.io.FileNotFoundException: File does not exist: /xxx
> {panel}
> This was caused by the deferred removal of deleted inodes from the inode map.
> Since getAdditionalBlock() acquires FSN read lock and then write lock, a
> deletion can happen in between. Because of deferred inode removal outside FSN
> write lock, getAdditionalBlock() can get the deleted inode from the inode map
> with FSN write lock held. This allow addition of a block to a deleted file.
> As a result, the edit log will contain OP_ADD, OP_DELETE, followed by
> OP_ADD_BLOCK. This cannot be replayed by NN, so NN doesn't start up or SBN
> crashes.
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