While error testing is about finding bugs in your software, performance testing is about ensuring your code works as intended and delivers the results you expect when a very high number of end-users are attempting to access your service at the same time.
Performance testing is a testing process for system stability and responsiveness under given workloads. The goal of performance testing is to find and eliminate anything that might cause performance problems by testing scenarios such as:
Application and command response times
The velocity of data transfer
Stability under various workloads
Concurrent user volume
Network bandwidth usage
Developers run performance tests to ensure software and systems will perform as expected in production and deliver a positive experience for end-users. Many of these tests can be categorized as front-end performance tests, vs. more traditional load, or back-end, testing. Application and command response times, the velocity of data transfer, memory consumption, and bandwidth usage can be measured via metrics such as first contentful paint, time to interactive, speed index, and more.
The biggest benefit of performance testing is that it validates the fundamental features of the software. For example, how quickly an app loads, especially for mobile users, can significantly impact usage. Research by Google shows that more than half (53%) of visitors will leave a mobile site if it doesn’t load within three seconds.
Performance testing allows you to monitor the essential components of your software under duress to evaluate scalability, identify discrepancies and resolve issues, and improve optimization.
Performance testing puts your software and web apps through the paces to help you find potential problems, including:
Server performance plays a big part in app responsiveness. If the server is struggling under volume, web apps can load slowly.
A lack of load balancing or code problems can cause bottlenecks in processing requests. Synch issues, memory leaks, and inefficient code can also cause issues.
Improper load balancing leads to poor response times which can be frustrating to users. Locking contention, missing indexes, and inefficient queries in-app databases can also create poor response times.
Your software or web app may work fine in the development stage, but what happens when it’s released and there are hundreds, thousands, or tens of thousands of people using it at the same time?
Different types of performance tests measure various scenarios and components. Here are the most common tests.
Front-end performance testing encapsulates measures that impact user experience including how quickly basic page features load, how quickly functional elements become responsive (at all) to user actions, and how quickly functional elements are able to carry out user requests. These metrics help developers understand what has the biggest impact on user-perceived performance
Load testing measures performance under expected workloads. This helps establish baselines for general system behavior, latency, and throughput to validate performance criteria.
Stress testing pushes applications past their normal load conditions to put them under stress. It helps to find the “breaking point” where a component fails or encounters problems.
Scalability testing typically uses stress tests in a series. By steadily increasing system resources, you can evaluate how your app can handle additional capacity and usage. This can help identify bottlenecks or trigger when you need to add additional resources.
Spike testing looks at performance during sudden traffic spikes. An eCommerce platform, for example, may spike during holiday shopping seasons or sales periods.
Soak testing examines the performance of loads over extended periods. Soak tests typically run for several hours to evaluate the impact of memory leaks, server performance, or disk space over time.
Endurance testing observes how applications handle the processing load for longer periods, such as days or months.
Volume testing is a subset of load testing to check performance when processing large data volumes. This helps ensure no data is lost as the database size grows and system pressure increases.
Similar to stress testing, breakpoint testing helps determine the maximum capacity levels where systems will perform to minimal requirements. Also called capacity testing, incremental loads are applied until things “break.”
Configuration testing examines performance with multiple combinations of software/hardware. By testing different combinations, you can find optimal configurations and eliminate bottlenecks.
Isolation testing breaks down the system into different modules for testing. Most commonly, this is done when performance issues or bugs are challenging to find. Isolating various modules helps testers narrow the search until bugs are identified for resolution.
Things always seem to work more efficiently in your environment where you have tight controls, but end-users will be using the internet to access your systems. Internet testing helps determine end-user performance over various internet speeds and connections.
Making sure your apps render quickly across different devices and operating systems, providing rapid response to user input, and creating the user experience you envisioned are all part of performance testing. No matter what you’ve designed in the production environment, you need to ensure end-users get quality performance in the real world.
The best performance testing tools will allow you to create a continuous testing environment for continual optimization across your development and operations cycles.
By automating your performance tests, you can continually monitor performance to broaden test coverage and deliver bug-free apps.
Live testing on real devices using thousands of browser and operating system configurations makes sure your apps and websites work for everyone.
Each of the different types of performance tests has the same goal: test applications and systems for optimal performance under different real-life scenarios.
Here are the basic steps to take you through the performance testing process:
Define the environment you will use for testing. This includes the physical environment, production environment, and testing tools you will be using.
How will you gauge and assess performance? You need to establish acceptable performance criteria against which your tests will be measured. This includes setting baselines for performance for normal workloads, spikes, and endurance.
Identify use cases and key simulations you will need to test. Effective performance testing will test scenarios under different loads and usages. In the test design phase, you will also need to define what metrics will be gathered and used to assess acceptable performance or areas that need further attention.
In this step, you are preparing your test environment and getting tools and resources ready before execution.
After you have prepared and configured your test environment, it’s time to execute your various tests and capture the results.
After running the tests, you need to analyze the results at each stage and compare them to your baselines for acceptable performance. Make any necessary changes, fine-tune, and then retest to see if changes increase or decrease performance.
Performance testing produces better apps and allows you to release them with confidence. At Sauce Labs, we ensure your mobile apps and websites work flawlessly on every browser, operating system, and device. Contact Sauce Labs today to learn how automating your tests can produce better results.