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https://issues.apache.org/jira/browse/IGNITE-7533?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16345070#comment-16345070
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Dmitriy Pavlov commented on IGNITE-7533:
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New Speed based approach was implemented in throttling. Speed calculations
invovles fsync()'ed pages count and evicted pages count. New speed-based
throttling is enabled by default (if throttling is enabled).
To enforce previous implementation it is possible to setup option
IgniteSystemProperties.IGNITE_OVERRIDE_WRITE_THROTTLING_ENABLED
to value "ratio"
> Throttle writting threads according fsync progress and checkpoint writting
> speed instead of region fill
> -------------------------------------------------------------------------------------------------------
>
> Key: IGNITE-7533
> URL: https://issues.apache.org/jira/browse/IGNITE-7533
> Project: Ignite
> Issue Type: Improvement
> Components: persistence
> Affects Versions: 2.3
> Reporter: Dmitriy Pavlov
> Assignee: Dmitriy Pavlov
> Priority: Major
> Fix For: 2.5
>
> Attachments: image (2).png, imageRatioBased.png, imageSpeedBased.png
>
>
> Throttling implemented under IGNITE-6334 is based on region fill percentage
> (ditry pages ratio) and current checkpoint progress.
> But actual progress of writting is based on write operation complete, but not
> on fsync() complete.
> Suppose following stage of CP is currently running: most of data is being
> written and fsync is started. Fsync on experiments requires more time than
> write, but throttling is disabled for that stage. There is enough time to
> unthrottled grid to fill remaining 16% of clear pages to get sufficient 75%
> of dirty pages and writes stops.
> Fsync progress is to be included in checkpoint progress, but actual fsync
> progress reported by OS is irregular both on Linux and Windows. See picture,
> green line is fsync progress, and yellow is write complete.
> Because fsync progress reported is not regular (the differences are 3-4
> orders of magnitude) it is suggested to implement new speed based throttling
> policy.
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