Re: Impact of old data on performance

2012-03-01 Thread Dan Retzlaff
I've never had to deal with GC tuning since our cluster has relatively few (but large) columns. So I'll leave further comment to others, but it sounds like you're on the right track. On Thu, Mar 1, 2012 at 2:13 AM, Stefan Reek wrote: > ** > Swap is disabled on the machines, so I'm sure the JVM i

Re: Impact of old data on performance

2012-02-29 Thread Dan Retzlaff
First to be clear, I'm not an expert but I suggested "cfstats" because it can show unhealthy signs. That said, yours looks okay to me: few live SSTables per column family, reasonable quantity of data... The next things I'd verify are that (1) the JVM isn't swapping out during these periods of bad p

Re: Impact of old data on performance

2012-02-29 Thread Stefan Reek
Hi Dan, Thanks for answering. I included the output of cfstats below. I hope you can say something about our problems with it. cheers, Stefan Keyspace: Keyspace1 Read Count: 60703419 Read Latency: 1.1790332096286043 ms. Write Count: 105871791 Write Latency: 0.019847457393065166

Re: Impact of old data on performance

2012-02-28 Thread Dan Retzlaff
Hi Stefan. Can you share the output of nodetool cfstats? On Tue, Feb 28, 2012 at 1:50 AM, Stefan Reek wrote: > Hi All, > > We are running a 3-node cluster with Cassandra 0.6.13. > We are in the process of upgrading to 1.x, but can't do so for a while > because we can't take the cluster offline.

Impact of old data on performance

2012-02-28 Thread Stefan Reek
Hi All, We are running a 3-node cluster with Cassandra 0.6.13. We are in the process of upgrading to 1.x, but can't do so for a while because we can't take the cluster offline. Until now 0.6.13 has run without problems, but lately we are getting some performance issues. We are getting timeouts