You might want to show us the GC log's... if there are promotion failures, count on the objects which you can get by inspecting the heapdumps etc, I am kind of assuming stuff :)
Regards, </VJ> On Thu, Jun 28, 2012 at 11:01 PM, Gurpreet Singh <gurpreet.si...@gmail.com>wrote: > Vijay, > Thanks for the suggestion. > Row Key size is 8 bytes (its a long). > Is the issue here incorrect calculation really? > The server already had the key cache in memory when i stopped it, and it > was using abt 6 gigs of heap total. How is it tht it cannot startup again > with the same keycache? > > /G > > > On Thu, Jun 28, 2012 at 4:25 PM, Vijay <vijay2...@gmail.com> wrote: > >> > It has 13.7million keys >> How big is your Row Keys? Current calculation (in 1.1) assumes that the >> average size of the Entry<RowKey, Long> in the keycache is 16 bytes. >> >> One thing which you can do to get out this issue is to reduce the >> Keycache to a low enough to get the server started or increase the Heap to >> hold all the objects. (If you are using the visualVM try to see the object >> counts). >> >> Regards, >> </VJ> >> >> >> >> >> On Thu, Jun 28, 2012 at 3:40 PM, Gurpreet Singh <gurpreet.si...@gmail.com >> > wrote: >> >>> Vijay, >>> I am running into an issue right now, not sure if its related to this >>> one. >>> >>> My cassandra 1.1 was running fine for a week, and the key cache size (as >>> checked by jconsole) increased to almost 650 mb. It has 13.7million keys. I >>> have set key_cache_size_in_mb to 800 mb. I checked the heap size, and it >>> was at 6 gigs. All good! >>> However, when i try to restart cassandra, it is unable to start now. >>> Before i shut it down, it seemed fine at 6 gigs, which means its able to >>> handle the memory requirements just fine. However it is not able to start >>> up anymore with the same key cache. jconsole says that the heap is full. >>> >>> Thanks >>> /G >>> >>> >>> On Thu, Jun 28, 2012 at 12:22 PM, Vijay <vijay2...@gmail.com> wrote: >>> >>>> in 1.1 we dont calculate the Key size accurately, hence we have the fix >>>> in https://issues.apache.org/jira/browse/CASSANDRA-4315 >>>> >>>> Regards, >>>> </VJ> >>>> >>>> >>>> >>>> >>>> On Thu, Jun 28, 2012 at 11:25 AM, Gurpreet Singh < >>>> gurpreet.si...@gmail.com> wrote: >>>> >>>>> 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 >>>>>> >>>>> >>>>> >>>> >>> >> >
