> Now keep adding clients until it stops making the numbers go up... Neither adding additional readers nor additional cluster nodes showed performance gains. The numbers, they do not move.
-- David Schoonover On Jul 19, 2010, at 5:18 PM, Jonathan Ellis wrote: > Now keep adding clients until it stops making the numbers go up... > > On Mon, Jul 19, 2010 at 2:51 PM, David Schoonover > <david.schoono...@gmail.com> wrote: >> Sorry, mixed signals in my response. I was partially replying to suggestions >> that we were limited by the box's NIC or DC's bandwidth (which is gigabit, >> no dice there). I also ran the tests with -t50 on multiple tester machines >> in the cloud with no change in performance; I've now rerun those tests on >> dedicated hardware. >> >> >> reads/sec @ >> nodes one client two clients >> 1 53k 73k >> 2 37k 50k >> 4 37k 50k >> >> >> Notes: >> - All notes from the previous dataset apply here. >> - All clients were reading with 50 processes. >> - Test clients were not co-located with the databases or each other. >> - All machines are in the same DC. >> - Servers showed about 20MB/sec in network i/o for the multi-node clusters, >> which is well under the max for gigabit. >> - Latency was about 2.5ms/req. >> >> >> At this point, we'd really appreciate it if anyone else could attempt to >> replicate our results. Ultimately, our goal is to see an increase in >> throughput given an increase in cluster size. >> >> -- >> David Schoonover >> >> On Jul 19, 2010, at 2:25 PM, Stu Hood wrote: >> >>> 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. >>> >> >> > > > > -- > Jonathan Ellis > Project Chair, Apache Cassandra > co-founder of Riptano, the source for professional Cassandra support > http://riptano.com
