(2005-07-18) Design For Feedback

Bill De Hora on System Design: Sean was telling me last night about some performance profiling he'd been doing for a multi-stage, multi-pipe XML processing line - let's just say that where the bottlenecks turned up were counter intuitive - I absolutely guessed wrong, but of course I did - it's a given that you'll guess wrong. So you have to measure - but to measure you have to build something to measure - you won't solve these kind of issues during architecture-picture-time. Spend architecture-picture-time making sure you can build something which can be measured later on. In other words, design for FeedBack.