> First time I tun single instance of Cassandra and my application on a system > (16GB ram and 8 core), the time taken was 480sec. > When I added one more system ,(means this time I was running 2 instance > of Cassandra in cluster) and running application from single client , I > found time taken in increased to 1000sec. And I also found that that data > distribution was also very odd on both system (in one system data were about > 2.5GB and another were 140MB). > Is any configuration require while running Cassandra in a cluster other than > adding seeds ?
For starters: (1) Are you spreading your data around evenly across row? Rows determine where data is placed in the cluster. (2) Is your ring actually balanced? (nodetool ring, they should have 50/50) (3) Is your test concurrent/multi-threaded? Increasing total time would be expected if you're moving from local traffic only to running against remote machines, if your test is a sequential workload. Adding machines increases aggregate throughput across multiple clients; it won't make individual requests faster (except indirectly of course by avoiding overloaded conditions). -- / Peter Schuller
