anyone have an explanation for this? This kinda screws up memory calculations.
/G On Mon, Jun 25, 2012 at 5:50 PM, Gurpreet Singh <gurpreet.si...@gmail.com>wrote: > Hi, > I have a question about cassandra 1.1 > > Just wanted to confirm if key_cache_size_in_mb is the maximum amount of > memory that key cache will use in memory? If not, what is it? > > My observations: > With key cache disabled, I started cassandra. I invoked Full GC through > jconsole a couple of times just to make sure that memory is freed up. > Total heap memory in use is 2.2 gigs. I have almost 550 million keys, so > this looked reasonable as the bloom filter itself is around 1 gig. > > I enabled key cache again by making key_cache_size_in_mb to a value 800. > This would lead cassandra to load a previously saved key cache file of size > 98 mb on disk. I restarted cassandra again. This time the heap size > increased to 4.2 gigs. I checked the cache sizing in jconsole. > > KeyCacheCapacityInMb: 799 > KeyCacheSize: 410,316,048 > > This says that the key cache size is 410 mb. However the increase in the > heap is 2 gigs. Doesnt add up!! > > Can anyone explain this? > Thanks > Gurpreet >
