Load testing

The VIP Platform is designed to scale its resources under most conditions, making it generally unnecessary to load test a site. Prior to initiating any load or stress testing, notify VIP by creating a Support ticket and outline the objectives and planned methodology of the load test.

VIP recommends analyzing a site’s performance prior to launching the site, and again after real traffic is reaching the site and make adjustments where needed. Portions of application code that may not perform well under load can be identified by looking at individual requests or a history of activity.

Make use of front-end analysis tools in a browser, or via webpagetest.org, to identify potential browser performance issues.

General guidelines for load testing

• If implementing and testing changes, a baseline test should be run before and after those changes are made.
• Tests should be stopped as soon as the fail threshold has been achieved.
• Traffic should be increased gradually (ramped-up) and take into account that URLs that have been saved to the edge cache will have a much faster load time for future requests (hits).
• When determining the number of concurrent users/second to test with, take into account that on average only 1/10th of the user requests would reach the origin datacenter. To make the test more realistic, use the total number of requests which should reach the origin datacenter.
• The most critical aspects of site resilience and performance are cache hit rate and the speed of page generation for origin requests (i.e. uncached requests). Do not intentionally use cache-busting query parameters, non-GET requests, or requests with cookies that might invalidate caching at the edge.
• Ideally, tests should come from different locations.