Excellent :-) I can't wait to see more results. Ian.
On 21 Nov 2006, at 16:11, Michael Rogers wrote: > Here are some preliminary results from the simulator - I must > stress that they're only preliminary. I haven't simulated token > passing yet - these results only show throttling with backoff, > throttling alone, and backoff alone. > > The load model is a bit simplistic: one in ten nodes is a > publisher, and each publisher has ten randomly selected readers. > Each publisher occasionally inserts a key, waits for ten minutes, > then informs its readers of the key; the readers then request the > key. The publication rate (and therefore the request rate) can be > varied to investigate the effect of load. > > Each run lasted for three hours' simulation time, with the first > hour's logs discarded to minimise the effect of the initial > conditions. > > All three mechanisms showed an increase in throughput under > increasing load, ie there was no congestion collapse. Throttling > alone produced higher throughput than either throttling with > backoff or backoff alone, especially under heavy load. > > All three mechanisms showed a decrease in success rate with > increasing load, suggesting that congestion collapse might > eventually occur at high enough loads. Throttling alone produced a > higher success rate and slower degradation under load than either > throttling with backoff or backoff alone. > > This suggests that the backoff mechanism is not effective in > controlling load, and the request throttle would work better > without backoff. These conclusions are only tentative though - much > more remains to be done, when I can find enough disk space for the > logs!
