[ 
https://issues.apache.org/jira/browse/CASSANDRA-5863?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

T Jake Luciani updated CASSANDRA-5863:
--------------------------------------

    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.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Reply via email to