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https://issues.apache.org/jira/browse/CASSANDRA-3623?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13175789#comment-13175789
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Vijay commented on CASSANDRA-3623:
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Network is because the test has 12 nodes and it is responding to the read
requests all the nodes are showing similar data if you want i can send u the
data.
Mean while your claim here is that snappy library is taking more CPU because we
give it DirectBB?
Can you plz conform you tried v2 and gives a worse performance than trunk and
it is Linux (v1 doesn't give a better performance gains where as v2 does)?
if yes i can close this ticket may be it is just me/AWS(Unknown reason) which i
am not sure and i dont have bare metal to test on.
> 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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