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https://issues.apache.org/jira/browse/ACCUMULO-4112?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15107253#comment-15107253
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Keith Turner commented on ACCUMULO-4112:
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I was using 1.8.0-SNAPSHOT (an older version, I have a branch for ACCUMULO-4066
that I have not rebased in while). Looking at the attached test one difference
with my scenarion is it uses BatchWriter. Fluo uses ConditionalWriter and
BatchWriter. The ConditionalWriter will be much more sensitive to these
pauses.
> MinC start/stop updates are always hsync'd
> ------------------------------------------
>
> Key: ACCUMULO-4112
> URL: https://issues.apache.org/jira/browse/ACCUMULO-4112
> Project: Accumulo
> Issue Type: Bug
> Components: tserver
> Environment: Fluo testing on a 20-node cluster
> Reporter: Eric Newton
> Assignee: Eric Newton
> Priority: Minor
> Attachments: MinCFlushPerfTest.java
>
>
> [~kturner] writes:
> {quote}
> I was running a Fluo test with 1.8.0-SNAP on my workstation. My Fluo table
> had a ton of tablets. I was seeing terrible performance. I started
> looking at the tserver and noticed it was always calling hsync. I tracked
> down the problem to the fact that when minc start and stop events are written
> to the log they are always written w/ sync level. My poor little tserver
> was constantly minor compacting (probably had around 600 tablets that were
> all being written to).
> I changed the test config to create like 15 tablets and the performance was
> much better. All cores were 100% utilized, which was not the case when hsync
> was always called.
> {quote}
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