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https://issues.apache.org/jira/browse/CASSANDRA-1283?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Daniel Kluesing updated CASSANDRA-1283:
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Attachment: trunk-pluggableCache.txt
The CLHM has some draw backs, mainly high storage overhead. Letting the OS
manage the cache is better on the overhead, but operationally not workable.
When compaction kicks in, you have no control over which data the OS will page
out and no ability to mlock. This leads to unpredictable disk activity, and
unpredictable request latency. Using something like memcached let us get 2x
better storage efficiency from the row cache, which translates into a big cost
savings for our cluster, while being more explicit about what's in cache. This
patch makes the row cache pluggable and allows different cache implementations
to be used for different column families.
-Makes the row cache a generic and pluggable interface
-Provides wrappers for using memcached or CLHM as the row cache provider
-Allows row cache provider to be set on a per CF basis
-Extends the latency tracker to keep some finer grained throughput numbers
I forward ported this from 0.6.2 to trunk. It probably has some bugs against
trunk, we have it in production as a part of our 0.6.2 setup. If this intrigues
people I can put more effort into checking for bugs against trunk, but all unit
tests pass.
And clearly it's not to everyone's taste to call memcache from java. In our
tests it was the best for our workload and the cost savings large . You could
do ehcache instead or any other cache. To use this particular memcached wrapper
you need http://code.google.com/p/spymemcached/
> Make the row cache pluggable
> -----------------------------
>
> Key: CASSANDRA-1283
> URL: https://issues.apache.org/jira/browse/CASSANDRA-1283
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Reporter: Daniel Kluesing
> Priority: Minor
> Fix For: 0.8
>
> Attachments: trunk-pluggableCache.txt
>
>
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