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Posted to commits@cassandra.apache.org by "T Jake Luciani (JIRA)" <ji...@apache.org> on 2013/08/08 19:01:49 UTC
[jira] [Updated] (CASSANDRA-5863) Create a Decompressed Chunk Cache
[ https://issues.apache.org/jira/browse/CASSANDRA-5863?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
T Jake Luciani updated CASSANDRA-5863:
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Description:
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. Initially this could be a off heap cache but it would be great to put these decompressed chunks onto a SSD so the hot data lives on a fast disk similar to https://github.com/facebook/flashcache.
was:
Currently, for every read the CRAR we reads compressed chunks into a byte[], check sends it to ICompressor and 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. Initially this could be a off heap cache but it would be great to put these decompressed chunks onto a SSD so the hot data lives on a fast disk similar to https://github.com/facebook/flashcache.
> Create a Decompressed Chunk Cache
> ---------------------------------
>
> Key: CASSANDRA-5863
> URL: https://issues.apache.org/jira/browse/CASSANDRA-5863
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Reporter: T Jake Luciani
>
> 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. Initially this could be a off heap cache but it would be great to put these decompressed chunks onto a SSD so the hot data lives on a fast disk similar to https://github.com/facebook/flashcache.
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