If you put 25 processes on each of the 2 machines, all you are testing is how fast 50 processes can hit Cassandra... the point of using more machines is that you can use more processes.
Presumably, for a single machine, there is some limit (K) to the number of processes that will give you additional gains: above that point, you should use more machines, each running K processes. -----Original Message----- From: "David Schoonover" <david.schoono...@gmail.com> Sent: Monday, July 19, 2010 1:02pm To: user@cassandra.apache.org Subject: Re: Cassandra benchmarking on Rackspace Cloud > Multiple client processes, or multiple client machines? I ran it with both one and two client machines making requests, and ensured the sum of the request threads across the clients was 50. That was on the cloud. I am re-running the multi-host test against the 4-node cluster on dedicated hardware now to ensure that result was not an artifact of the cloud. David Schoonover On Jul 19, 2010, at 1:38 PM, Jonathan Ellis wrote: > On Mon, Jul 19, 2010 at 12:30 PM, David Schoonover > <david.schoono...@gmail.com> wrote: >>> How many physical client machines are running stress.py? >> >> One with 50 threads; it is remote from the cluster but within the same >> DC in both cases. I also run the test with multiple clients and saw >> similar results when summing the reqs/sec. > > Multiple client processes, or multiple client machines? > > -- > Jonathan Ellis > Project Chair, Apache Cassandra > co-founder of Riptano, the source for professional Cassandra support > http://riptano.com
