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https://issues.apache.org/jira/browse/HDFS-8046?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14394439#comment-14394439
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Kihwal Lee commented on HDFS-8046:
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Test failures are not related. No new test case added since it only changes the
sleep time to be configurable. It's hard to add a meaningful test for this.
- TestRetryCacheWithHA - HDFS-7524
- TestFailureToReadEdits#testFailureToReadEditsOnTransitionToActive\[0\] -
After the test case timed out on a new checkpoint, the mini dfs cluster
shutdown. But the standby was actually done with checkpointing and uploading
the image at that point. The SBN said "Exception during image upload..." on
shutdown. So it looks like a timing issue in the test.
> Allow better control of getContentSummary
> -----------------------------------------
>
> Key: HDFS-8046
> URL: https://issues.apache.org/jira/browse/HDFS-8046
> Project: Hadoop HDFS
> Issue Type: Bug
> Reporter: Kihwal Lee
> Assignee: Kihwal Lee
> Attachments: HDFS-8046.v1.patch
>
>
> On busy clusters, users performing quota checks against a big directory
> structure can affect the namenode performance. It has become a lot better
> after HDFS-4995, but as clusters get bigger and busier, it is apparent that
> we need finer grain control to avoid long read lock causing throughput drop.
> Even with unfair namesystem lock setting, a long read lock (10s of
> milliseconds) can starve many readers and especially writers. So the locking
> duration should be reduced, which can be done by imposing a lower
> count-per-iteration limit in the existing implementation. But HDFS-4995 came
> with a fixed amount of sleep between locks. This needs to be made
> configurable, so that {{getContentSummary()}} doesn't get exceedingly slow.
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