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https://issues.apache.org/jira/browse/CASSANDRA-5661?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13707684#comment-13707684
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Pavel Yaskevich commented on CASSANDRA-5661:
--------------------------------------------

Thanks, it worked that time, I did a quick test on local machine with global 
cache backed by MultiwayPool.

MultiwayPool average run: median 3.1, 95th 4.7, 99.9th 21.9
FileCacheService (+ LinkedTranferQueue) average run: median 2.4, 95th 3.0, 
99.9th 17.1

It's the same setup that I used in my previous test with no writes and no 
compaction.

I will try to experiment with ArrayBlockingQueue as we know upper bound on 
concurrency and update my FileCacheService patch with either of them (LTQ vs. 
ABQ) soon.
                
> Discard pooled readers for cold data
> ------------------------------------
>
>                 Key: CASSANDRA-5661
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-5661
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Core
>    Affects Versions: 1.2.1
>            Reporter: Jonathan Ellis
>            Assignee: Pavel Yaskevich
>             Fix For: 2.0
>
>         Attachments: CASSANDRA-5661-multiway-per-sstable.patch, 
> CASSANDRA-5661.patch, CASSANDRA-5661-v2-global-multiway-per-sstable.patch, 
> DominatorTree.png, Histogram.png
>
>
> Reader pooling was introduced in CASSANDRA-4942 but pooled 
> RandomAccessReaders are never cleaned up until the SSTableReader is closed.  
> So memory use is "the worst case simultaneous RAR we had open for this file, 
> forever."
> We should introduce a global limit on how much memory to use for RAR, and 
> evict old ones.

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