My data is single row/key to a 500 byte column and I’m reading ALL random keys (worst case read scenario) Cache has minimal effectiveness, so the Bloom trees and indexes are getting a real work out. I’m on 8GB Ubuntu 9.10 boxes (64bit). Yea, I was griping about the performance earlier, disk is heavily used by Cassandra, so outside of going to some highend SAS stuff, not sure what to do.
On Wed, May 5, 2010 at 6:36 PM, Mark Jones <MJones@imagehawk.com> wrote:
Have you actually managed to get 10K reads/second, or are you just estimating that you can? I’ve run into similar issues, but I never got reads to scale when searching for unique keys even using 40 threads, I did discover that using 80+ threads, I can actually reduce performance. I’ve never gotten more than 200-300 reads/second (steady state) off a 4 cluster node. I can get roughly 8K writes/second to the same cluster (although I haven’t tested both simultaneously with results worth talking about).
200-300/s is pretty low, especially if you can get 8k writes/s. I would estimate that you should be getting at least a couple thousand reads/s. Here is what I've gotten from a quad core machine with two disks:
How much data are you testing with?