Why Load Test?
There is nothing quite as reassuring as watching your computing world smoothly handle a workload of synthetically generated transactions long before the real peak arrives.
A load test allows you to identify future bottlenecks and buy yourself time to fix things and to save money. You could just wait for the peak you are planning for to come naturally and hope for the best. If it works, then all is well. If not, then you have no time to fix anything, no time to test the fixes, and only the most expensive options to fix things remaining on the table. The company will have to throw money and hardware at the problem and endure significant risk with untested workarounds. If performance is bad, there will be additional costs as customers move to your competitors, and the call center spends a lot more time saying “We’re really sorry.” to the customers who bother to call.
Capacity Planning Is The Hypothesis, Load Testing Is The Experimental Proof
Load testing can increase your confidence in your capacity planning efforts and show where you have way too much of a given resource, both of which can save your company serious money as you may be able to narrow the safety margin you use. Load testing can also help you tease apart the complex transaction mix generated naturally by the users so you can study the performance of each separate type of transaction.
No Perfection, But That Is OK
For those of you who believe that no load test can perfectly emulate your user load, I’m here to say you are absolutely correct. However, you can create load tests that are good enough to tell you lots of useful things about how your computing world responds to a heavy load. You learn something, and inch closer to the answers you need, with every load test you run… even the ones that fail miserably.
Lots More To Say…
Load testing is a big subject, so I’ll divide it over multiple future posts that focus on:
- Creating and validating the load test
- Different ways to use load testing
- Setting the goals of a load test
- Analyzing your load test results
- Lastly, load testing failures to avoid and opportunities to seize