[jira] [Issue Comment Deleted] (HBASE-17085) AsyncFSWAL may issue unnecessary AsyncDFSOutput.sync

["Duo Zhang (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HBASE-17085?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Duo Zhang updated HBASE-17085:
------------------------------
    Comment: was deleted

(was: In HBASE-16890 it is 463/272=1.70 and here it is 613/386=1.59. So I think it helps a little?

And see my latest comment in HBASE-17049, the sync count metrics of FSHLog and AsyncFSWAL can not be compared directly.

Anyway, I will keep trying other methods to aggregate more syncs.

Thanks [~stack].)

> AsyncFSWAL may issue unnecessary AsyncDFSOutput.sync
> ----------------------------------------------------
>
>                 Key: HBASE-17085
>                 URL: https://issues.apache.org/jira/browse/HBASE-17085
>             Project: HBase
>          Issue Type: Sub-task
>          Components: wal
>    Affects Versions: 2.0.0
>            Reporter: Duo Zhang
>            Assignee: Duo Zhang
>             Fix For: 2.0.0
>
>         Attachments: HBASE-17085-v1.patch, HBASE-17085-v2.patch, HBASE-17085-v2.patch, HBASE-17085.patch
>
>
> The problem is in appendAndSync method, we will issue an  AsyncDFSOutput.sync if syncFutures is not empty. The SyncFutures in syncFutures can only be removed after an AsyncDFSOutput.sync comes back, so before the AsyncDFSOutput.sync actually returns, we will always issue an  AsyncDFSOutput.sync after an append even if there is no new sync request.



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