I'm seeing some issues like this as well, in fact, I think seeing your graphs has helped me understand the dynamics of my cluster better.
Using some ballpark figures for inserting single column objects of ~500 bytes onto individual nodes(not when combined as a cluster): Node1: Inserts 12000/s Node2: Inserts 12000/s Node3: Inserts 9000/s Node4: Inserts 6000/s When combined as a cluster, inserts are around 7000/s (replication factor of 2) When GC kicks in anywhere in the cluster, Quorum writes slowdown for everyone associated with that node. And the fact that there are 4 Nodes, almost implies garbage collection will be going on somewhere almost all the time. So while I should be able to write more than 12,000/second, my slowest node in the cluster seems to overwhelm the faster nodes and drag everyone down. I'm still running tests of various combinations to see where things work out. From: Masood Mortazavi [mailto:masoodmortaz...@gmail.com] Sent: Monday, April 19, 2010 6:15 AM To: user@cassandra.apache.org; d...@cassandra.apache.org Subject: 0.6 insert performance .... Re: [RELEASE] 0.6.1 I wonder if anyone can use: * Add logging of GC activity (CASSANDRA-813) to confirm this: http://www.slideshare.net/schubertzhang/cassandra-060-insert-throughput - m. On Sun, Apr 18, 2010 at 6:58 PM, Eric Evans <eev...@rackspace.com<mailto:eev...@rackspace.com>> wrote: Hot on the trails of 0.6.0 comes our latest, 0.6.1. This stable point release contains a number of important bugfixes[1] and is a painless upgrade from 0.6.0. Enjoy! [1]: http://bit.ly/9NqwAb (changelog) -- Eric Evans eev...@rackspace.com<mailto:eev...@rackspace.com>
