I'm writing a capacity test tool for a client's web server. The idea is to measure count how many requests exceed the spec'ed response time under various loads, where load is specified as "M requests in N secs". So I need to generate those M requests spaced relatively evenly over N seconds, record the start time, and get a reasonably accurate idea of when each requests ends. I'm assuming that twisted callbacks will take care of the latter, and don't have any reason to dobut that. However, the former has turned out to be harder than I expected. I need to start the requests with the reactor running so that previous requests will be handled properly. The obvious solution - task.LoopingCall - isn't precise enough, taking up to 33% more time than I'd alloted. The second attempt - a loop using reactor.callLater with a delay based on the requests and time left. That does slightly better, but only slightly. Is there some other method that I might use for this? Or is twisted the wrong tool entirely. Thanx, http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information.