What's a ring cache? FYI if you're using the DataStax CQL drivers they will automatically route requests to the correct node.
On Sun Dec 07 2014 at 12:59:36 AM kong <kongjiali...@gmail.com> wrote: > Hi, > > I'm doing stress test on Cassandra. And I learn that using ring cache can > improve the performance because the client requests can directly go to the > target Cassandra server and the coordinator Cassandra node is the desired > target node. In this way, there is no need for coordinator node to route > the client requests to the target node, and maybe we can get the linear > performance increment. > > > > However, in my stress test on an Amazon EC2 cluster, the test results are > weird. Seems that there's no performance improvement after using ring > cache. Could anyone help me explain this results? (Also, I think the > results of test without ring cache is weird, because there's no linear > increment on QPS when new nodes are added. I need help on explaining this, > too). The results are as follows: > > > > INSERT(write): > > Node count > > Replication factor > > QPS(No ring cache) > > QPS(ring cache) > > 1 > > 1 > > 18687 > > 20195 > > 2 > > 1 > > 20793 > > 26403 > > 2 > > 2 > > 22498 > > 21263 > > 4 > > 1 > > 28348 > > 30010 > > 4 > > 3 > > 28631 > > 24413 > > > > SELECT(read): > > Node count > > Replication factor > > QPS(No ring cache) > > QPS(ring cache) > > 1 > > 1 > > 24498 > > 22802 > > 2 > > 1 > > 28219 > > 27030 > > 2 > > 2 > > 35383 > > 36674 > > 4 > > 1 > > 34648 > > 28347 > > 4 > > 3 > > 52932 > > 52590 > > > > > > Thank you very much, > > Joy >
