[
https://issues.apache.org/jira/browse/HDFS-6109?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14011663#comment-14011663
]
Andrew Wang commented on HDFS-6109:
-----------------------------------
Maybe we can reuse the FsDatasetAsyncDiskService available in FsDatasetImpl?
Right now it's used to do async deletes, but it seems apt to do this sort of
thing there too. It'd be good so we don't overload a single volume with
different types of I/O work.
> let sync_file_range() system call run in background
> ---------------------------------------------------
>
> Key: HDFS-6109
> URL: https://issues.apache.org/jira/browse/HDFS-6109
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: datanode
> Affects Versions: 3.0.0, 2.3.0
> Reporter: Liang Xie
> Assignee: Liang Xie
> Attachments: HDFS-6109-v2.txt, HDFS-6109.txt
>
>
> Through we passed SYNC_FILE_RANGE_WRITE to sync_file_range, to make it as
> asynchronous as possible, it still could be blocked, e.g. the os io request
> queue is full.
> Since we use sync_file_range just as a page cache advisor role:) it doesn't
> decide or guarantee the real durability, it would be nice if we could run it
> in backgroud. At least my test log showed, a few sync_file_range calls still
> cost tens of ms or more, due to the happened location is in the critical
> write path(BlockReceiver class), from a upper view, like HBase application,
> will "hung" tens of ms as well during Hlog syncing.
> Generally speaking, the patch could not improve too much, but, better than
> before, right ? :)
--
This message was sent by Atlassian JIRA
(v6.2#6252)
