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Benjamin Lerer commented on CASSANDRA-10971:
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Could we not just keep your latest design but track the number of buffers in
use and use it has a limit? Something like
[this|https://github.com/apache/cassandra/compare/trunk...blerer:10971-trunk].
{quote}As a nit, I think it might be safer to use an instanceof
FileDirectSegment for enforceSegmentLimit in trunk. In case somebody decide to
add a new sub-class to FileDirectSegment{quote}
Forget about that, I did not read the code properly.
> Compressed commit log has no backpressure and can OOM
> -----------------------------------------------------
>
> Key: CASSANDRA-10971
> URL: https://issues.apache.org/jira/browse/CASSANDRA-10971
> Project: Cassandra
> Issue Type: Bug
> Components: Local Write-Read Paths
> Reporter: Ariel Weisberg
> Assignee: Ariel Weisberg
> Fix For: 3.0.x, 3.x
>
>
> I validated this via a unit test that slowed the ability of the log to drain
> to the filesystem. The compressed commit log will keep allocating buffers
> pending compression until it OOMs.
> I have a fix that am not very happy with because the whole signal a thread to
> allocate a segment that depends on a resource that may not be available
> results in some obtuse usage of {{CompleatableFuture}} to rendezvous
> available buffers with {{CommitLogSegmentManager}} thread waiting to finish
> constructing a new segment. The {{CLSM}} thread is in turn signaled by the
> thread(s) that actually wants to write to the next segment, but aren't able
> to do it themselves.
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