[
https://issues.apache.org/jira/browse/HDFS-9494?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15120515#comment-15120515
]
GAO Rui commented on HDFS-9494:
-------------------------------
Thanks for your comments [~jingzhao].
bq. In DFSStripedOutputStream, we do not need to move all the data fields to
the beginning of the class.
I move them to the beginning of the class body cause when doing the fields
related coding, it had been a little trouble to find and edit(adding) fields to
{{DFSStripedOutputStream}}. Would it be easier for future coding if we move the
fields to the beginning?
bq. flushAllExecutor.shutdownNow() can be called in the finally section
bq. flushAllFuturesMap does not need to be a class level field. It can be a
temporary variable defined and used in flushAllInternals.
That makes a lot of sense. I will move {{flushAllExecutor.shutdownNow()}} to
finally section and make {{flushAllFuturesMap}} an local variable in the next
patch.
> Parallel optimization of DFSStripedOutputStream#flushAllInternals( )
> --------------------------------------------------------------------
>
> Key: HDFS-9494
> URL: https://issues.apache.org/jira/browse/HDFS-9494
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Reporter: GAO Rui
> Assignee: GAO Rui
> Priority: Minor
> Fix For: 3.0.0
>
> Attachments: HDFS-9494-origin-trunk.00.patch,
> HDFS-9494-origin-trunk.01.patch, HDFS-9494-origin-trunk.02.patch,
> HDFS-9494-origin-trunk.03.patch, HDFS-9494-origin-trunk.04.patch,
> HDFS-9494-origin-trunk.05.patch, HDFS-9494-origin-trunk.06.patch,
> HDFS-9494-origin-trunk.07.patch
>
>
> Currently, in DFSStripedOutputStream#flushAllInternals( ), we trigger and
> wait for flushInternal( ) in sequence. So the runtime flow is like:
> {code}
> Streamer0#flushInternal( )
> Streamer0#waitForAckedSeqno( )
> Streamer1#flushInternal( )
> Streamer1#waitForAckedSeqno( )
> …
> Streamer8#flushInternal( )
> Streamer8#waitForAckedSeqno( )
> {code}
> It could be better to trigger all the streamers to flushInternal( ) and
> wait for all of them to return from waitForAckedSeqno( ), and then
> flushAllInternals( ) returns.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
