AjaxWorld: Ben Rushlo and Rajeev Kutty
Designing for and managing performance in the new frontier of rich internet applications
Industry leader in web performance measurement (self-claim). Cannot retrofit performance at the end of a project, has to be built-in all through. Lots of factors changing performance management: browser as platform, page size, page complexity, languages, cloud, … etc. Application life cycle much faster (1-2 months, or faster). User expectations have risen: always on, always responsive. Web 2.0 changes expectations.
Best practices
- Have to test at every stage of the app lifecycle
- Test from the cloud – where the users are
- Test with a browser (what proportion of the time is spent in the browser engine)
- Use the right metrics (use many metrics, avoid “pet metrics”, avoid using a single metric
Web 2.0 performance challenges
Javascript files load one at a time (serialised). Minimise the number of external .js files. Don’t put all javascript links in the header.
Client-side processing can take a very large amount of the time taken by a page load. Tip: identify and reduce client-side processing
Third-party quality (adsense, mediatrack, tracking, etc). Third-party code can slow down the overall page (does not go into a separate thread). Tip: get a SLA in place; put the third-party links in footer not header where possible.
Web service performance can vary - get SLA’s in place.
Flash: balance size and number of flash files.
Basics: reduce the number of round trips (CSS sprites, HTTP keep alive, caching).
Measure, measure, measure.
Now available for free: KITE - Keynote Internet Testing Environment.