It helps with performance engineering. We recommend to not begin a large test at the maximum number of virtual users. Rather than run a test for 10 minutes beginning with 5,000 and ending with 5,000, we suggest to start smaller, for example, with 500 users and increase to 5,000 over an hour. This approach has the advantage of allowing your system to get all the parts working properly at smaller load (e.g. caches, threads, database connections) before the heavier volume starts exposing potential bottlenecks in your application. Also if the target server begins to fail during the test this provides more granularity into the number of concurrent users where failure begins. If the test starts at 5,000 and fails all that can be learned from the results is that it fails somewhere between 1 and 5,000 which isn’t very useful.

From what we’ve seen in thousands of load tests with LoadStorm, it is common to see useful patterns in the metrics before the peak traffic is reached, and these metrics point to areas of performance limitations that can be tuned.

Load testing is invariably coupled with performance tuning – an iterative process of test/tune/test/tune. Therefore, we recommend you ramp the volume in order to get more value from the test results.