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From Artur Kronenberg <>
Subject Heap requirement for Off-heap space
Date Fri, 11 Oct 2013 12:47:59 GMT

I was playing around with cassandra off-heap options. I configured 3 GB 
off-heap for my row cache and 2 GB Heap space for cassandra. After 
running a bunch of load tests against it I saw the cache warm up. Doing 
a jmap histogram I noticed a lot of offHeapkey objects. At that point my 
row cache was only 500 MB big. So I got worried on how this will affect 
Heap space when I manage to fill the entire off-heap.

Is there a formular that maps heap space to off-heap? Or more 
spicifically how much heap space does it require to manage 3 GB off-heap 



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