Hi, We are trying to use Cassandra for high-performance insertion of simple key/value records. I have set up Cassandra on two of my machines in my local network (Windows 2008 server), using pretty much the default configuration. I created a test driver in java (using thrift) which inserts a single 1K data column (keys are unique strings of integer values) with multiple threads. On each machine I am able to achieve around 9,000 inserts/sec when running the test driver with the local Cassandra server.
Then I set up a cluster with both machines, and ran the same test again (the test driver is still local to one of the Cassandra nodes). Surprisingly I did not see any improvement in the insert performance, I got the same 9000 inserts/sec as when running with a single node. I know that I shouldn't expect linear scaling to 18,000 operations/sec, but shouldn't I see at least some significant improvement? The CPU isn't fully loaded on either of the machines, and the network utilization is low too (1000 mbit network). Later on I also tested adding a third node, but that didn't improve anything either. I suspect I'm doing something wrong with setting up the cluster. The only changes I made on the second machine were: - AutoBootstrap=true - Setting 'Seed' to the IP of the other node Did I miss anything? Or am I simply wrong in expecting the throughput to scale when using multiple nodes? Thanks, Dirk
