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https://issues.apache.org/jira/browse/RATIS-1886?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17764919#comment-17764919
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Wei-Chiu Chuang commented on RATIS-1886:
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I don't see noticeable difference between 0ms and 1ms. My machines are slow and
hflush APIs are not as optimized as I'd like to, but it seems okay with 1ms for
now.
The clientWriteRequest latency on my cluster is around 8ms on average and I'd
like to ultimately reduce it to ~2ms or lower (that is how HDFS hflush latency
looks like on average on my machine)
> AppendLog sleep fixed time cause significant drop in write throughput
> ---------------------------------------------------------------------
>
> Key: RATIS-1886
> URL: https://issues.apache.org/jira/browse/RATIS-1886
> Project: Ratis
> Issue Type: Improvement
> Components: server
> Affects Versions: 2.5.1
> Reporter: Yaolong Liu
> Priority: Major
> Attachments: image-2023-09-13-15-44-00-933.png
>
>
> In https://issues.apache.org/jira/browse/RATIS-1793 , we enforce
> raft.server.log.appender.wait-time.min, which make GrpcLogAppender sleep
> fixed time during appendLog. This make alluxio master write throughput drop
> 50% and unacceptable. The ops of alluxio master could see below
> !image-2023-09-13-15-44-00-933.png!
> I noticed that this patch was introduced to avoid leader being too busy in
> some error conditions. Could we introduce sleep waiting when an error is
> discovered (maybe not easy) or find a way to locate the error condition and
> repair it completely? The performance degradation caused by sleeping for each
> appendLog request may be underestimated.
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