Agile software development isn’t really a “new” trend anymore. I mean, the Agile Manifesto turns 13 years old next month and while that might be early adolescence in human years, it’s downright ancient as far as trends in IT are concerned. However, one area that has yet to fully mature is the implementation of non-functional testing practices in a Continuous Testing sort of way that can keep pace with more Agile development teams. Load and performance testing definitely fall into that category. You might be a performance tester on a team that is just starting to do more iterative development or a more experienced Agile tester looking to add load and performance testing to your workflow; either way, you’ll likely want to know what you’re in for.
Agile development practices can help teams achieve faster time to market, adapt to changing requirements, provide a constant feedback loop, etc. The benefits of load and performance testing include determining how much load an application can handle before it crashes in production, when to add another server, when to reconfigure the network, where code needs to be optimized, etc. What is less well known is the fact that the combination of the two practices can lead to additional benefits that go beyond just the sum of the benefits of each practice, i.e. 1+1=3.
Some of these benefits include:
Avoiding Late Performance Problem Discovery
When load and performance testing are pushed off until the end of a development cycle, there is often little to no time for developers to make changes. This can cause teams to push back release dates and delay getting features out the door that customers need. Alternatively, if the issues are minor, teams may decide to proceed and launch the application into production while accepting the heightened risks. If the performance problems are more fundamental, they could even require painful architectural changes that could take weeks or months to implement.
Making Changes Earlier When They Are Cheaper
By including load and performance testing in Continuous Integration testing processes, organizations can catch performance issues early before they get much more costly to fix. Developers can instantly know that the new feature in the latest build has caused the application to no longer meet Service Level Agreements (SLAs). They can fix the problem then and there before it becomes exponentially more expensive. This is especially true on Agile teams when discovering a performance problem weeks later could mean that it actually occurred several builds ago which makes the task of pinpointing the root cause a nightmare.
Guaranteeing Users Get New Features, Not New Performance Issues
In some Agile organizations, changes are happening incredibly fast. It’s possible for a new feature or some new functionality to get checked into source control, run through a Continuous Integration build, pass all of the automated tests, and get deployed to the production server in a matter of minutes. But if that code wasn’t optimized to handle the number of simultaneous users seen at the worst peak times, it could cause the whole system to crash. Integrating load testing into the process before these changes are deployed to production can ensure that your users get all the goodies they want without the bad user experiences. This can save your company thousand or even millions in lost revenue from users switching to competitors’ apps or bashing your brand because of the problems they experienced with your app.
In the same way that combining Agile with load testing can provide unique benefits, it can also present your teams with unique challenges they may not have experienced in the past.
Shorter Development Cycles Require More Tests in Less Time
Load and performance testing are usually pushed off until the end of a development cycle. With Agile, development, cycles are much shorter, and load & performance testing can get pushed off until the last day of a sprint or sometimes it’s done every other sprint. This can often result in code being released without being adequately tested or user stories slipping to the next release once they have been tested. Conceptually the solution is to do the testing earlier in the development cycle, but that’s easier said than done with many teams lacking the resources and tools to make it happen.
“Working” Code Does Not Always Perform Well
So much focus for developers on Agile teams is put on delivering “working” code, but is code really “working” if it fails when the application is under load? Should user stories and tasks really be marked as “done” if the code associated with them causes the application to crash with 100 users? What about 1,000? 100,000? The pressure to get code out the door is high, but so is the cost of having an application crash in production.
Developers Need Feedback NOW
Agile developers need to know more than just the fact that their code is causing performance issues: they need to know when their code started causing problems and what story they were working on when the issue started. It’s a huge pain for developers to be forced to go back and fix code for a story they worked on weeks or months ago. It also means they can’t spend time working on getting new features out the door. Detecting performance issues early in the cycle so you can deliver important feedback to developers quickly is crucial to saving costs.
Automating the Handoff from Dev to Ops Can Feel Risky
While DevOps and Continuous Deployment are still fairly young practices, the fear felt by operations teams that new changes in code will slow down or even crash the application when it is deployed in production has been around forever. Automating some of the testing in the Continuous Integration process can help to ease some of this fear, but without adequate performance testing included, the risk is still real. Ops teams know well the huge impact application downtime can have on the business.
As daunting as some of these challenges seem, don’t lose sight of the benefits you’ll receive. Load and performance testing successfully in an Agile way can save an organization a lot in costly bug fixes and could make a tester a hero to both development and operations teams alike.
Not quite sure how to get started? Stay tuned for my next blog on best practices for Agile load and performance testing.