I'm seeing a cluster of 4 (replication factor=2) to be about as slow overall as the barely faster than the slowest node in the group. When I run the 4 nodes individually, I see:
For inserts: Two nodes @ 12000/second 1 node @ 9000/second 1 node @ 7000/second For reads: Abysmal, less than 1000/second (not range slices, individual lookups) Disk util @ 88+% How many nodes are required before you see a net positive gain on inserts and reads (QUORUM consistency on both)? When I use my 2 fastest nodes as a pair, the thruput is around 9000 inserts/second. What is a good to excellent hardware config for Cassandra? I have separate drives for data and commit log and 8GB in 3 machines (all dual core). My fastest insert node has 4GB and a triple core processor. I've run py_stress, and my C++ code beats it by several 1000 inserts/second toward the end of the runs, so I don't think it is my app, and I've removed the super columns per some suggestions yesterday. When Cassandra is working, it performs well, the problem is that is frequently slows down to < 50% of its peaks and occasionally slows down to 0 inserts/second which greatly reduces aggregate thruput.
