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https://issues.apache.org/jira/browse/CASSANDRA-3623?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13175598#comment-13175598
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Vijay commented on CASSANDRA-3623:
----------------------------------

The above test was done on 12 node cluster but the response time and the hot 
methods where collected from one random node in the cluster. 
This test was executed on AWS M2.4xl's with heap settings of 12/2.
                
> use MMapedBuffer in CompressedSegmentedFile.getSegment
> ------------------------------------------------------
>
>                 Key: CASSANDRA-3623
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-3623
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Core
>    Affects Versions: 1.1
>            Reporter: Vijay
>            Assignee: Vijay
>              Labels: compression
>             Fix For: 1.1
>
>         Attachments: 0001-MMaped-Compression-segmented-file-v2.patch, 
> 0001-MMaped-Compression-segmented-file.patch, 
> 0002-tests-for-MMaped-Compression-segmented-file-v2.patch
>
>
> CompressedSegmentedFile.getSegment seem to open a new file and doesnt seem to 
> use the MMap and hence a higher CPU on the nodes and higher latencies on 
> reads. 
> This ticket is to implement the TODO mentioned in CompressedRandomAccessReader
> // TODO refactor this to separate concept of "buffer to avoid lots of read() 
> syscalls" and "compression buffer"
> but i think a separate class for the Buffer will be better.

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