What is performance testing and what are the popular tools?

Performance testing objectives

The main objectives of conducting performance tests are:

• Responsiveness evaluation: Measuring the system’s response time to user actions or requests at different load levels.
• Identifying bottlenecks (bottlenecks): Finding system components (e.g., database, application server, network) that limit overall system performance.
• Determine scalability limits: Determine what maximum load (e.g., number of concurrent users, number of transactions per second) a system can handle before its performance begins to fall below an acceptable level.
• Verification of stability and reliability: Verify that the system operates stably and without failure during prolonged load (load tests, stress tests).
• Capacity planning (capacity planning): Gathering the data needed to plan for future infrastructure needs as the number of users or data grows.
• Comparing the performance of different versions: Evaluating the impact of code or configuration changes on system performance.

Types of performance tests

Performance testing includes several specific types of tests:

• Load Testing: Simulating the expected normal or peak load on a system to evaluate its behavior under these conditions.
• Overload Testing (Stress Testing): Intentionally subjecting a system to a load that exceeds its normal limits in order to identify a breaking point and see how the system handles failure and recovery.
• Soak/Endurance Testing (Soak/Endurance Testing): Subjecting a system to an expected load for an extended period of time in order to detect problems that may arise after prolonged operation (e.g., memory leaks).
• Spike Testing: Simulating sudden spikes in load to see how the system responds to them.
• Isolation Testing (Isolation Testing): Testing the performance of individual system components in isolation to identify bottlenecks.
• Scalability Testing (Scalability Testing): Evaluating how system performance changes as workloads increase or resources are added.

Popular performance testing tools

Performance testing uses specialized tools that can simulate the actions of multiple virtual users and measure key performance metrics. Popular tools include:

• Apache JMeter: an open-source, very popular Java-based tool primarily used for performance testing of web applications and APIs.
• LoadRunner: A commercial, advanced tool from Micro Focus (formerly HP) that offers extensive testing capabilities for various types of applications.
• k6: A modern, open-source load testing tool, written in Go, focusing on ease of use and integration with development processes.
• Gatling: an open source load testing tool written in Scala, known for its high performance and good support for modern protocols.
• Cloud tools: Many cloud providers (AWS, Azure, GCP) offer their own services for cloud-scale load testing.

Performance testing process

Performance testing typically includes the steps of planning (defining objectives, scenarios, metrics), preparing the environment and test scripts, executing the tests, monitoring the system during testing, analyzing the results and reporting, and performance tuning to remove identified bottlenecks.

Summary

Performance testing is a key component of software quality assurance, especially for web applications, transactional systems and other multi-user solutions. It allows to evaluate and optimize system responsiveness, stability and scalability, ensuring positive user experience and application performance reliability under load.