What was the request rate and total bandwidth flowing at your peak? How far is that from your theoretical potential on the box?
On 21 Jun 2010, at 16:58, snacktime wrote: > Interested in some feeback on this (does it sound right?), or maybe > this might be of interest to others. > > We are launching a new facebook app in a couple weeks and we did some > load testing over the weekend on our unicorn web cluster. The servers > are 8 way xeon's with 24gb ram. Our app ended up being primarily cpu > bound. So far the sweet spot for the number of unicorns seems to be > around 40. This seemed to yield the most requests per second without > overloading the server or hitting memory bandwidth issues. The > backlog is at the somaxconn default of 128, I'm still not sure if we > will bump that up or not. Increasing the number of unicorns beyond a > certain point resulted in a noticable drop in the requests per second > the server could handle. I'm pretty sure the cause is the box > running out of memory bandwidth. The load average and resource usage > in general (except for memory) would keep going down but so did the > requests per second. At 80 unicorns the requests per second dropped > by more then half. I'm going to disable hyperthreading and rerun some > of the tests to see what impact that has. > > Chris > _______________________________________________ > Mongrel-users mailing list > Mongrelfirstname.lastname@example.org > http://rubyforge.org/mailman/listinfo/mongrel-users _______________________________________________ Mongrel-users mailing list Mongrelemail@example.com http://rubyforge.org/mailman/listinfo/mongrel-users