mutator.execute() timings - big variance noted - pointers needed on understanding/improving it

2011-03-10 Thread Roshan Dawrani
Hi, I am in the middle of some load testing on a 1-node Cassandra setup. We are not on very high loads yet. We have recorded the timings taken up by mutator.execute() calls and we see this kind of variation during the test run: So, 25% of the times, execute() calls come back in 25 milli-seconds,

Re: mutator.execute() timings - big variance noted - pointers needed on understanding/improving it

2011-03-10 Thread sridhar basam
Sounds like GC from your description of fast-slow-fast. Collect GC times from both the client and server side and plot against your application timing. If you uncomment the verbose GC entries in the cassandra-env.sh file you should get timing for the server side, pass in the same arguments for

Re: mutator.execute() timings - big variance noted - pointers needed on understanding/improving it

2011-03-10 Thread aaron morton
http://wiki.apache.org/cassandra/FAQ#slows_down_after_lotso_inserts Aaron On 11 Mar 2011, at 05:08, sridhar basam wrote: Sounds like GC from your description of fast-slow-fast. Collect GC times from both the client and server side and plot against your application timing. If you

Re: mutator.execute() timings - big variance noted - pointers needed on understanding/improving it

2011-03-10 Thread Roshan Dawrani
Hi All, Thanks for the inputs. I will start investigating this morning with the help of these. Regards, Roshan On Fri, Mar 11, 2011 at 2:49 AM, aaron morton aa...@thelastpickle.comwrote: http://wiki.apache.org/cassandra/FAQ#slows_down_after_lotso_inserts