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https://issues.apache.org/jira/browse/HDFS-5283?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13795500#comment-13795500
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Tsz Wo (Nicholas), SZE commented on HDFS-5283:
----------------------------------------------
- In FSNamesystem.isInSnapshot(..), we can safely assume the blockUC is
non-null and put blockUC.getBlockCollection() in a local variable in the very
beginning. Also the assert should be hasReadLock() instead of hasWriteLock()
since the method does not write anything.
{code}
//FSNamesystem
public boolean isInSnapshot(BlockInfoUnderConstruction blockUC) {
assert hasReadLock();
final BlockCollection bc = blockUC.getBlockCollection();
if (bc == null || !(bc instanceof INodeFileUnderConstruction)) {
return false;
}
final INodeFileUnderConstruction inodeUC = (INodeFileUnderConstruction) bc;
...
}
{code}
- For DFSOutputStream.abort(), it is better to add DFSTestUtil.abortStream(..)
than change it to public. Sorry that I did not see this previously.
> NN not coming out of startup safemode due to under construction blocks only
> inside snapshots also counted in safemode threshhold
> --------------------------------------------------------------------------------------------------------------------------------
>
> Key: HDFS-5283
> URL: https://issues.apache.org/jira/browse/HDFS-5283
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: snapshots
> Affects Versions: 3.0.0, 2.1.1-beta
> Reporter: Vinay
> Assignee: Vinay
> Priority: Blocker
> Attachments: HDFS-5283.000.patch, HDFS-5283.patch, HDFS-5283.patch,
> HDFS-5283.patch, HDFS-5283.patch
>
>
> This is observed in one of our env:
> 1. A MR Job was running which has created some temporary files and was
> writing to them.
> 2. Snapshot was taken
> 3. And Job was killed and temporary files were deleted.
> 4. Namenode restarted.
> 5. After restart Namenode was in safemode waiting for blocks
> Analysis
> ---------
> 1. Since the snapshot taken also includes the temporary files which were
> open, and later original files are deleted.
> 2. UnderConstruction blocks count was taken from leases. not considered the
> UC blocks only inside snapshots
> 3. So safemode threshold count was more and NN did not come out of safemode
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