It’s Never Too Early to Think About Performance
分类：【架构师该知道97件事】
It’s Never Too Early to Think About Performance
Rebecca Parsons
BuSinESS uSERS SpECiFy THEiR nEEdS primarily through functional requirements. The nonfunctional aspects of the systems, like performance, resiliency, up-time, support needs, and the like, are the purview of the archi- tect. However, often the preliminary testing of nonfunctional requirements is left until very late in the development cycle, and is sometimes delegated com- pletely to the operations team. This is a mistake that is made far too often. The reasons are varied. There is presumably no sense in making something fast and resilient if it doesn’t actually perform the required function. The envi- ronments and tests themselves are complex. Perhaps the early versions of the production system will not be as heavily utilized. However, if you aren’t looking at performance until late in the project cycle, you have lost an incredible amount of information as to when performance changed. If performance is going to be an important architectural and design criterion, then performance testing should begin as soon as possible. If you are using an Agile methodology based on two-week iterations, I’d say performance testing should be included in the process no later than the third iteration. Why is this so important? The biggest reason is that at the very least you know the kinds of changes that made performance fall off a cliff. Instead of having to think about the entire architecture when you encounter performance prob- lems, you can focus on the most recent changes. Doing performance testing early and often provides you with a narrow range of changes on which to focus. 26 97 Things Every Software Architect Should Know In early testing, you may not even try to diagnose performance, but you do have a baseline of performance figures to work from. This trend data provides vital information in diagnosing the source of performance issues and resolv- ing them. This approach also allows for the architectural and design choices to be vali- dated against the actual performance requirements. Particularly for systems with stringent requirements, early validation is crucial to delivering the system in a timely fashion. Technical testing is also notoriously difficult to get going. Setting up appro- priate environments, generating the proper data sets, and defining the neces- sary test cases all take a lot of time. By addressing performance testing early, you can establish your test environment incrementally, thereby avoiding much more expensive efforts once you discover performance issues. Dr. Rebecca Parsons is ThoughtWorks’ chief technology officer. She has more than 20 years’ application development experience, in industries ranging from telecommunications to emergent Internet services. Rebecca has published in both language and artificial intelligence publications, served on numerous program committees, and reviews for several journals. She has extensive experience leading in the creation of large-scale distributed object applications and the integration of disparate systems.
上一篇One Line of Working Code Is Worth 500 of Specification
顶0踩0
，也会有想更换的念头。旅行，正好提供了这样一个机会，
