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From Jonathan Ellis <>
Subject Re: ParNew and caching
Date Fri, 18 Nov 2011 23:15:39 GMT
No i/o?  No sstable counts going up in cfhistograms?

Is the heap so full you're experiencing GC pressure that way?

On Fri, Nov 18, 2011 at 3:46 PM, Todd Burruss <> wrote:
> Ok, I figured something like that.  Switching to
> ConcurrentLinkedHashCacheProvider I see it is a lot better, but still
> instead of the 25-30ms response times I enjoyed with no caching, I'm
> seeing 500ms at 100% hit rate on the cache.  No old gen pressure at all,
> just ParNew crazy.
> More info on my use case is that I am picking 50 columns from the 70k.
> Since the whole row is in the cache, and no copying from off-heap nor disk
> buffers, seems like it should be faster than non-cache mode.
> More thoughts :)

Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of DataStax, the source for professional Cassandra support

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