cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Pavel Yaskevich (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (CASSANDRA-5863) In process (uncompressed) page cache
Date Mon, 25 Apr 2016 05:23:13 GMT

    [ https://issues.apache.org/jira/browse/CASSANDRA-5863?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15255913#comment-15255913
] 

Pavel Yaskevich commented on CASSANDRA-5863:
--------------------------------------------

Indeed it comes with expense of utilizing inode cache more but not having to worry about keeping
CompressionInfo in memory and all other effects and complexities which come from current state
of compression might be worth it. We'll definitely need some experimental results to back
it up but even if it doesn't work out the way I expect it still would be an interesting experiment
to make.

> In process (uncompressed) page cache
> ------------------------------------
>
>                 Key: CASSANDRA-5863
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-5863
>             Project: Cassandra
>          Issue Type: Sub-task
>            Reporter: T Jake Luciani
>            Assignee: Branimir Lambov
>              Labels: performance
>             Fix For: 3.x
>
>
> Currently, for every read, the CRAR reads each compressed chunk into a byte[], sends
it to ICompressor, gets back another byte[] and verifies a checksum.  
> This process is where the majority of time is spent in a read request.  
> Before compression, we would have zero-copy of data and could respond directly from the
page-cache.
> It would be useful to have some kind of Chunk cache that could speed up this process
for hot data, possibly off heap.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message