There's no way to stress-test a complex web realtime system without actually running it on the real hardware. You'd expect very nonlinear behavior between numb

There's no way to stress-test a complex web realtime system without actually running it on the real hardware. You'd expect very nonlinear behavior between number of users, response time and number of machines used. Not being a part of Disqus, the only way I see to "predict" performance beyond the load already seen is to try and use past data from the current real system.