The Basics of Performance & Load Testing

ilan oulu

9 years ago

Performance testing and ultimately load testing, are both part of the crucial last phase of development. If done right, they will ensure that your software or app will run smoothly in the hands of your users. So let’s dive into a short guide on what exactly are performance and load testing.

What is Performance Testing?

The moment your application is ready to ship, all the features are in place and it’s looking great, it’s time for one last stage before you break out the champagne.

It needs to be tested.

That doesn’t just mean making sure it works, but testing how fast it works with a few users, loading times under strain, application behavior under different malfunctions, and so on… So let’s break these stages down and understand the levels of application testing.

The basic testing of your app’s usability is called performance testing. This round of testing measures your application’s performance in realistic usage – or in other words, how your app would perform in the hands of your future users.
Any basic usage test is in fact a performance test, from measuring loading times to checking server response rates. Usually performance testing will measure the functionality of the software in the hands of one user, and in optimal conditions – testing each usage case at a time.

A crucial phase of performance testing is load testing. Here you measure the performance of the application in realistic peak usage, straining the network or using a number of features at the same time. The importance of this form of testing is that it will demonstrate your app’s limits, and portray its ability to operate normally under realistic stress.

The most robust form of performance testing is soak testing and stress testing. These two forms of testing measure the software’s performance under extreme or prolonged conditions. Stress testing is used to find the software’s “breaking point”, subjecting it to extreme usage, overloading the server with requests and testing the app’s performance under artificial system and hardware failures.

On the other hand, soak testing measures the software’s performance over time, normally this means running multiple load tests over a number of days to measures performance degrading rates.

Conducting Load Testing – The Right Way

We want to be sure our software will function properly, that’s where performance testing comes in. We also want to be sure it will still perform well with 10, 100 and hopefully thousands of users loading it up and performing different actions – this is where load and soak testing come in.

If you have the time and resources to take your testing even further – then it’s always wise to perform a few stress testing scenarios, to find cracks in the software at extreme usage.

Performance testing must be done in levels, starting at base user usage runs during development of features. If you’ll try and run complex multi-user load tests before you’ve properly tested all the features under optimal conditions, you’ll be wasting your time. Only after conducting a number of load testing runs, can you consider soak and stress testing.

This all seems logical, but you’d be surprised how many people jump a few stations across the way, and discover failures in their software – without a clue as to what caused them.

This is why a good testing team needs to build a testing strategy, based on their potential user base, type of application, and complexity of features.

Using an external testing service is extremely advisable – especially at the final stages of development. They say “there’s no second chance for a first impression…” you’ve got to get your software just perfect on the day of launch, or disappear in a sea of software developed by your competition.

Interested in taking your own software or application to the next level?