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https://issues.apache.org/jira/browse/CASSANDRA-7438?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14072260#comment-14072260
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Benedict commented on CASSANDRA-7438:
-------------------------------------
OK, let's chalk those results up to some weirdness then (maybe they were sync,
not async thrift?). Just wanted to see some without that.
I haven't reviewed the patch, and don't really consider myself proficient to do
so, but those numbers look fine for the stated goal. I do slightly wonder if we
couldn't achieve this without having to use native code (this ring buffer could
be implemented reasonably straight-forwardly in Java using unsafe instead),
which would be easier for the current committer base to understand and
maintain, but I don't have anything otherwise against the patch if there are
others proficient/competent enough to review. It seems a good high-level
approach for solving the problem.
> Serializing Row cache alternative (Fully off heap)
> --------------------------------------------------
>
> Key: CASSANDRA-7438
> URL: https://issues.apache.org/jira/browse/CASSANDRA-7438
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Environment: Linux
> Reporter: Vijay
> Assignee: Vijay
> Labels: performance
> Fix For: 3.0
>
> Attachments: 0001-CASSANDRA-7438.patch
>
>
> Currently SerializingCache is partially off heap, keys are still stored in
> JVM heap as BB,
> * There is a higher GC costs for a reasonably big cache.
> * Some users have used the row cache efficiently in production for better
> results, but this requires careful tunning.
> * Overhead in Memory for the cache entries are relatively high.
> So the proposal for this ticket is to move the LRU cache logic completely off
> heap and use JNI to interact with cache. We might want to ensure that the new
> implementation match the existing API's (ICache), and the implementation
> needs to have safe memory access, low overhead in memory and less memcpy's
> (As much as possible).
> We might also want to make this cache configurable.
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