[
https://issues.apache.org/jira/browse/HDFS-10742?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15471815#comment-15471815
]
Arpit Agarwal commented on HDFS-10742:
--------------------------------------
Thank you [~chris.douglas]. Your patch lgtm.
bq. I remain skeptical of AutoCloseableLock, since one could just use the Lock
in interface and existing tooling to implement the same. But if its virtues are
obvious to everyone but me I won't stand in the way of including it.
As you said its syntactic sugar. If this approach feels that inelegant I am
okay with eliminating {{AutoCloseableLock}}.
bq. Second, minutiae like "GC-friendliness", whether a wrapper class on Lock
adds dispatch overhead, class loading overhead, etc. when this JIRA logs
critical sections longer than 300ms are irrelevant, literally by orders of
magnitude.
Moot point now but iiuc the object would have been allocated on every lock
acquire whether we logged or not. Perhaps the overhead would have been
negligible but I'm not sure myself.
> Measurement of lock held time in FsDatasetImpl
> ----------------------------------------------
>
> Key: HDFS-10742
> URL: https://issues.apache.org/jira/browse/HDFS-10742
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: datanode
> Affects Versions: 3.0.0-alpha2
> Reporter: Chen Liang
> Assignee: Chen Liang
> Attachments: HDFS-10742.001.patch, HDFS-10742.002.patch,
> HDFS-10742.003.patch, HDFS-10742.004.patch, HDFS-10742.005.patch,
> HDFS-10742.006.patch, HDFS-10742.007.patch, HDFS-10742.008.patch,
> HDFS-10742.009.patch, HDFS-10742.010.patch, HDFS-10742.011.patch,
> HDFS-10742.012.patch, HDFS-10742.013.patch, HDFS-10742.014.patch,
> HDFS-10742.015.patch
>
>
> This JIRA proposes to measure the time the of lock of {{FsDatasetImpl}} is
> held by a thread. Doing so will allow us to measure lock statistics.
> This can be done by extending the {{AutoCloseableLock}} lock object in
> {{FsDatasetImpl}}. In the future we can also consider replacing the lock with
> a read-write lock.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
