Software Performance Testing Best Practices

Testing the software performance is an important task that you can’t afford to overlook. Performance has huge impact on user experience, the speed of your business and other factors. Nowadays software comes in a variety of shapes and sizes, taking into account its complexity and architecture. In this piece I will try to cover everything you need to know about software performance testing best practices.

Software performance testing (also known as load testing) is a key part of ensuring the performance, availability, reliability and scalability of software systems. It is an invaluable process for all software applications that are deployed on-premises, across the cloud and for mobile/web applications. The fact remains that we can never fully anticipate every scenario that could impact an application’s end users, which is why it’s crucial for companies to undergo thorough performance testing. Companies often use hardware in-house or outsource the testing process to a third party. Whatever the method may be, there are several best practices you can use to optimize not only your processes but also your results. In this article I will cover some of these best practices and tools you can use to make sure that your performance testing runs as efficiently as possible.

There are different types of performance testing that help determine the readiness of the system to work on specific conditions:

Load Testing: Validating the application’s ability to perform under anticipated loads.
Spike Testing: Testing the application’s response to sudden large spikes in the load.
Endurance Testing: Validating whether the application can handle the expected load in the long run.
Scalability Testing: Validating the application’s effectiveness to scale up and support an increase in the user load.
Volume Testing: Monitoring a system against a high volume of data generated to understand its performance under different database volumes.

Effective testing of an application’s performance is critical to the success of any application software. Without a proper performance testing in place, it may cause the application to fail in the long run, or hamper its usability altogether.

Conducting performance testing can add great value to the entire application lifecycle and help in creating applications that are devoid of performance issues.

We know that performance testing is measured in both qualitative and quantitative terms. Attributes such as response time and the ability to process several instructions every second efficiently are quantitative attributes.

On the other hand, qualitative attributes include reliability, scalability, stability, and interoperability, which needs to be evaluated to measure the efficiency of the system.

Best practices for conducting effective performance testing

When it comes to conducting performance testing, there are several best practices that can help you improve its overall effectiveness. Here are five best practices for conducting effective performance testing.

1. Understand your application

Before you go through with the implementation, it is very important to understand the application, the capabilities it offers, its intended use, and the kind of conditions in which it is supposed to thrive.

Your team should also understand and know the limitations of the application. Try to list out the common factors that might affect the performance of the application and consider these parameters while testing.

2. Make it a part of your Unit tests

Many times, we implement performance testing in the later stages of the application development lifecycle. It is difficult and more costly to implement changes later on in the development process. Therefore, it is always advisable to implement performance testing as part of your unit tests. This will help your team to quickly identify performance issues and rectify them as the development progresses.

There are different approaches to testing, and when it comes to unit testing, most teams focus on various sections of code, and not on the functionality of the application.

Implementing performance testing will not only help you identify issues early but will also allow your developers to be closely involved with the testers and improve the quality of the software to meet the expectations of the performance.

3. Set realistic performance benchmarks

Sometimes the expectations you may have from your application may not be realistic. That is why it is very important to set realistic baselines by picking practical and realistic scenarios. You need to ensure that the testbed includes different varieties of devices and environments in which your application will have to thrive.

For example, traffic can be expected from different devices, browsers, and operating systems. However, the load cannot be predicted for sure. So, all of the different devices and environments should be taken into consideration while evaluating the performance of the application.

Secondly, test simulation cannot start from zero. Most tests are conducted right from the base followed by adding load until the desired threshold is reached. However, this is not realistic, and this provides the test engineer with a false picture of system load. The fact is that the load may not go down to nil and slowly progress from there.

4. Understand performance from the user’s perspective

Even though you may have a clear understanding of performance testing, it is important to understand the user perspective.

We tend to focus on the response of the servers; however, it is also important to consider the user experience. If your server load tests are satisfactory, it does not mean that your users will have the same experience.

Tests should capture each user’s experience, and user interfaces timings systematically with concomitance to the metrics derived from the server.

Combining the user perspectives, including a Beta version of the product can enable you to capture the complete user experience.

The behavior of the users can be monitored and metrics can be derived to measure the experience. This will help you solve all the experience related issues before releasing the application to the masses.

5. Implement DevOps

Today, most of the companies are striving for shorter development cycles with test automation. However, if we look at performance testing, it is a time-consuming process and requires constant human intervention to bring it to success.

Implementing DevOps culture will help you to bring together your development and testing teams together and help you to identify errors through continuous testing and solve them immediately.

Many companies are also using containers and microservices. The containerized approach helps testers to easily test each function in isolation and identify errors to be solved in the early stages of the development.

Performing Testing is a critical element for the success of any application. Though it may be considered a time-consuming process, it can aid your goal to develop successful applications. eInfochips assists global enterprises with its expertise in quality assurance and test automation and has also created a unified testing framework that offers end-to-end testing. Know more about our QA and test automation expertise.

A Dozen Performance Testing Best Practices to Consider

Following are twelve best practices for designing and running a well-functioning application performance testing program. Some of these are older, ‘classic’ concepts, and some are newer, reflecting the fundamental changes that have come to IT environments. Testing teams should think about how to incorporate these objectives in their performance testing programs.

1. Go for pragmatism over perfection

Performance testing isn’t easy, particularly in modern IT environments. It’s hard to get it right and impossible to do it perfectly. As a result, some organizations don’t do any performance testing, and that’s a big mistake. Even if they have limited tools or capabilities, avoiding the challenge isn’t a viable strategy. Organizations should begin performance testing now and do what they can. Whatever testing will be undertaken, it will involve measurement. Since you can’t measure what you can’t observe, teams need visibility. With application monitoring, teams can see how an application is behaving. To change or fix that behavior, they need to understand what’s going on inside an application. But it all starts with monitoring.

2. Gain the advantages of open testing

With open workload systems, if the target application slows down, the testing system will monitor itself in order to ensure that the right amount and the desired types of traffic are consistently sent to the target application. This is an improvement over closed testing systems (See #12) which tend to slow down as the application they are testing slows down, thereby skewing the results.

Little’s law, a formula in queueing theory, explains this effect in any scenario that involves things in line awaiting an action. A simplified visualization of this law involves a coffee shop and a barista. At this shop, 50 people per hour come in, and the barista services them well. Looking only at in-store activity, the closed test would show that the barista is doing well servicing all the customers who enter. That’s not the whole picture, however. The closed system’s test does not recognize the 100 customers who are waiting in line outside, or the 200 people who saw the long line and simply left. Open testing would be able to show how the barista does when the number of customers per hour entering the store varies.

3. Use the full array of available tests

Some IT and DevOps teams tend to equate load testing with performance testing, when in fact the former is just a subset of the latter. It is always better to have more data and intelligence than less, so it’s a good idea for teams to broaden their programs by including more than just load tests. Here is a quick look at some of the more popular and useful test types.

Load tests – These are essentially volume tests. They produce traffic loads that mimic various conditions in production environments. The loads are then directed at the application being tested. Putting that simulated demand on an application (or a website or other software resource), reveals in advance how the application will behave under those various conditions.
Soak tests – These tests are designed to replicate heavy traffic loads that also have long durations. They show how apps hold up against persistently high demand – many concurrent users, high transaction rates, etc. These tests are also useful in that they can uncover problems that only arise over long periods of time, such as memory leaks.
Spike tests – These let teams preview how their applications will behave when they are experiencing the heaviest demand. Take a very large ticket brokering company as an example. That company would want to know how its ticket sales app will perform a few minutes before and after they open tickets sales for a big concert. Assessing how well their app can handle extremely high numbers of concurrent users and transaction rates is critical to their business.
Stress tests – These tests determine how much an application can take, its absolute top-end, before it breaks and fails. These can also be used to determine the capacity of a system. You run a stress test with increased load until the quality criterias are violated.
Resilience/elasticity tests – These tests determine how well an application can get additional resources allocated to it, and quickly shift from its normal resources to back-up systems in order to maintain its availability and performance due to one or more failure conditions.

4. Define success and test to those metrics

Organizations are unique. Each one has its own business model and processes, and different needs that its applications and IT environments must meet. IT, DevOps, and QA teams should ensure that their application performance testing regimens reflect the actual needs of the business. It follows that success will look different from one organization to the next. Therefore, organizations need to develop their own, specific definition of application performance success, and test to it. Not too much, not too little, but just right.

5. Design tests that reflect human behaviors

Some teams have the skill sets and budgets needed for writing their own test scripts. For teams using commercial products, many of those offerings enable users to tailor or customize tests. In any case, teams should do what they can to design their testing packages so that they mimic real-world activity. One such item is humans’ ‘think time’. When people encounter an application that doesn’t respond instantaneously, they react in various different ways. Some instantly hit the ‘enter’ key again and then do so repeatedly. Others are more patient and pause for some length of time before hitting the ‘Enter’ key again. The same goes for a website that’s slow to load. People exhibit ‘think time’ and those times can vary widely. For this reason, a good testing approach is to an exponential distribution to randomize think time. Real users react differently and performance tests should reflect this reality.

6. Establish a performance culture

Under older styles of application development, testing was slotted in late in the process which made it seem like an afterthought. Under Agile methods, testing needs to be iterative throughout the whole process. Performance testing needs to be an integral part of the product development process overall, including CI/CD processes – equal in importance to all other phases. In fact, performance testing is just a small part of a larger cultural change that is required. It’s not unlike how organizations and staff have embraced security as not just a specific function, but a way to think and operate. Building a performance culture requires change at multiple levels – process, workflow, management visibility, staffing, budget, and more. As with any cultural change, top management and team leaders need to be proactive about building and sustaining their performance culture.

7. Test all resources and layers of the stack

In today’s environments, applications can be dynamically spun up or down on demand – all in the cloud. Applications themselves have different component elements (CPU, RAM, replicas, etc.) that are handled in the orchestration and management layer. Beneath that are the runtime and provisioning layers. Since an application relies on all layers of the cloud-native stack, the performance of all of those layers, and each of the main components within each layer, should be tested individually and collectively.

8. Keep tests focused in the realm of possible

While it may be interesting to know how an application performs under super-light loads, or what its breaking point is, those metrics are not very useful because the conditions being replicated occur rarely, if ever. A better approach, especially for organizations with small staffs and budgets, is to design their application performance tests so they replicate workloads that have a decent chance of actually occurring in production.

9. Real users are mobile-first, tests should be, too

Applications today often have different iterations ranging from traditional (installed on a PC or desktop), cloud based (such as Office365) and importantly, mobile (for access via smartphones or tablet). Whatever the range of access models and use cases may be, teams should have the capabilities required to test back-end or API performance of all the different application types and access methods. Application performance testing regimens should absolutely encompass the full range of usage scenarios involving different device types.

10. Ensure that reports are dialed-in

With good and consistent reporting, valuable test results can be shared across an organization to help with decision-making about future development priorities. Conversely, with poor reporting, insights from – and the value of – application performance testing can get lost. That can be avoided by tailoring content for the intended audience (i.e. technical or non-technical).

11. Prioritize and take remedial actions

Application performance testing is only as valuable as teams make it. And to maximize that value, teams must prioritize the surfaced issues, and be empowered to act on them. Performance testing provides data and insights; acting on those insights can produce strategic and tactical advantages. Whether it’s fixing a found bug or validating the efficacy of a new development direction, real value stems from taking action. High-quality testing can light up the right paths for these actions.

12. Avoid the pitfalls of closed testing systems

Closed systems have been around for decades and are still a big part of many performance testing programs. With closed testing, the testers set a fixed number of concurrent agents, isolated from one another, each performing a defined sequence of tasks over and over again in a loop. As discussed in #2 above, the main shortcoming of these systems is that as the tests they generate slow down the application being tested, they also slow down the testing tool itself, which skews the results.

Conclusion

Organizations of all kinds are migrating their IT operations to cloud architectures for reasons that are well-chronicled. They are tapping virtually infinite resources and changing the ways they do business with more virtualization, software-driven IT infrastructure, and cloud-native applications. Some are taking it a step further with AI Ops, where they use artificial intelligence and machine learning to automate their IT operations.

Whether it’s an organization’s first foray into cloud-based architectures, or they embraced the cloud early on, one thing is clear. Organizations need application performance testing capabilities that are just as powerful, sophisticated, and dynamic as the modern applications and other cloud-based resources they need to test.

Legacy testing approaches and systems simply will not get today’s testing job done. The challenge that teams must overcome is two-fold – accurately observing (and understanding) performance issues, and then being able to fix those problems.

The good news is that this technology has advanced, and high-quality, cloud-centric application performance testing solutions are commercially available now.

Forewarned is forearmed. Getting an accurate picture in advance of how their applications and other resources will work in production and perform under varying conditions, gives companies definite strategic and tactical advantages. It just takes the right testing system to gain those advantages.