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https://issues.apache.org/jira/browse/KUDU-1954?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15936844#comment-15936844
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Todd Lipcon commented on KUDU-1954:
-----------------------------------
Started writing various notes here:
https://docs.google.com/document/d/17-2CcmrjxZY0Gd9wDUh83xCCNL574famw8_2Bhfu-_8/edit?usp=sharing
> Improve maintenance manager behavior in heavy write workload
> ------------------------------------------------------------
>
> Key: KUDU-1954
> URL: https://issues.apache.org/jira/browse/KUDU-1954
> Project: Kudu
> Issue Type: Improvement
> Components: perf, tserver
> Affects Versions: 1.3.0
> Reporter: Todd Lipcon
> Attachments: mm-trace.png
>
>
> During the investigation in [this
> doc|https://docs.google.com/document/d/1U1IXS1XD2erZyq8_qG81A1gZaCeHcq2i0unea_eEf5c/edit]
> I found a few maintenance-manager-related issues during heavy writes:
> - we don't schedule flushes until we are already in "backpressure" realm, so
> we spent most of our time doing backpressure
> - even if we configure N maintenance threads, we typically are only using
> ~50% of those threads due to the scheduling granularity
> - when we do hit the "memory-pressure flush" threshold, all threads quickly
> switch to flushing, which then brings us far beneath the threshold
> - long running compactions can temporarily starve flushes
> - high volume of writes can starve compactions
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