On Fri, Jun 18, 2010 at 8:00 AM, Olivier Mallassi <omalla...@octo.com> wrote: > I use the default conf settings (Xmx 1G, concurrentwrite 32...) except for > commitlog and DataFileDirectory : I have a raid0 EBS for commit log and > another raid0 EBS for data. > I can't get through 7500 write/sec (when launching 4 stress.py in the same > time). > Moreover I can see some pending tasks in the > org.cassandra.db.ColumnFamilyStores.Keyspace1.Standard1 MBean > Any ideas on the bottleneck?
Your instance has 7.5G of RAM, but you are limiting Cassandra to 1G. Increase -Xmx to 4G for a start. You are likely to get significantly better performance with the ephemeral drive, as well. I suggest testing with commitlog on the ephemeral drive for comparison. b
