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https://issues.apache.org/jira/browse/CASSANDRA-9318?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14605539#comment-14605539
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Jonathan Ellis commented on CASSANDRA-9318:
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* default timeout is 2s not 10, so actually fine in your example of 300MB vs
150MB/s x 2s
* but we can easily set a higher limit on MS heap -- maybe as high as 1/8 heap
as default which gives us a *lot* of room for 8GB heap
* you don't see a complete halt until capacity's worth of requests timeout all
at once, because you don't get an entire capacity load accepted at once. it's
more continuous than discrete -- you pause until the oldest expire, accept
more, pause until the oldest expire, etc. so you make slow progress as load
shedding can free up memory. thus, load shedding is complementary to flow
control.
* aggressively load shedding for "outlier" nodes is a good idea that we should
follow up on in another ticket. again, current behavior of continuing to
accept requests until we fall over is worse than imposing flow control, so we
should start with that [flow control] in 2.1 and make further improvements in
2.2.
> Bound the number of in-flight requests at the coordinator
> ---------------------------------------------------------
>
> Key: CASSANDRA-9318
> URL: https://issues.apache.org/jira/browse/CASSANDRA-9318
> Project: Cassandra
> Issue Type: Improvement
> Reporter: Ariel Weisberg
> Assignee: Ariel Weisberg
> Fix For: 2.1.x, 2.2.x
>
>
> It's possible to somewhat bound the amount of load accepted into the cluster
> by bounding the number of in-flight requests and request bytes.
> An implementation might do something like track the number of outstanding
> bytes and requests and if it reaches a high watermark disable read on client
> connections until it goes back below some low watermark.
> Need to make sure that disabling read on the client connection won't
> introduce other issues.
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