Performance Testing Tutorial (Definition, Types, Metrics, Example)

Performance Testing

Performance testing is a software testing method for calculating a software application's speed, reaction time, stability, dependability, scalability, and resource utilization under a particular workload. The primary goal of performance testing is to observe and take out performance bottlenecks in software applications. It is also called "Perf Testing" and is a part of performance engineering.

The goal of performance testing is to determine how well a software product performs.

  • The application's speed determines how soon it reacts.

  • The greatest user load that a software application can handle is determined by its scalability.

  • Stability - Determines whether or not the application is steady when subjected to varying loads.

What is the purpose of performance testing?

A software system's features and functionality aren't the only things to consider. The performance of a software application, such as reaction time, dependability, resource utilization, and scalability, is important. The purpose of performance testing is to eliminate performance bottlenecks, not to uncover bugs Performance testing is accomplished to give information to stakeholders regarding their application's performance, stability, and scalability. Performance Testing, moreover, reveals what has to be addressed before a product is released to the market.

Without performance testing, the software is more hope to have issues like slowness when multiple people are utilizing it at the same time, instability across different operating systems, and poor usability. Under expected workloads, performance testing will establish whether their program satisfies speed, scalability, and stability criteria. Programs that are launched to the market with poor performance metrics as a result of insufficient or non-existent performance testing are hoping to earn a bad reputation and fail to fulfill sales targets

Mission-critical applications, such as space launch programs or life-saving medical equipment, should also be performance tested to verify that they operate without interruption for an extended length of time.

According to Dunn & Bradstreet, 59 percent of Fortune 500 organizations have an average weekly downtime of 1.6 hours. Given that the average Fortune 500 business pays $56 per hour to its minimum of 10,000 employees, the labor component of downtime expenses for such a corporation would be $896,000 per week or more than $46 million per delay of only 5 minutes (19-Aug-13) is predicted to cost the search giant $545,000. A recent Amazon Web Service outage is believed to have cost businesses $1100 per second in lost sales.

As a result, performance testing is critical.

Performance Testing Types

  • Load Testing − Load testing evaluates an application's ability to handle expected user loads. Before the software program goes online, the goal is to identify performance bottlenecks.

  • Stress Testing − Stress testing is the process of putting an application through its paces to see how well it manages high traffic or data processing. The goal is to figure out where an application's breaking point is.

  • Endurance testing − Endurance testing ensures that the program can withstand the predicted load for an extended length of time.

  • Spike testing − Spike testing examines the software's response to big spikes in user-generated load.

  • Volume Testing − Volume testing entails a huge number of tests. Data is entered into a database, and the general behavior of the software system is monitored. The goal is to test the performance of a software application with varied database volumes.

  • Scalability testing − The goal of scalability testing is to see how well a software program "scales up" to sustain an increase in user load. It aids in the planning of capacity expansion for your software system.

Typical Performance Issues

Speed, response time, load time, and inadequate scalability are the most common performance issues. One of the most crucial characteristics of an application is its speed. Potential consumers will abandon a slow-running application. Performance testing ensures that your program operates quickly enough to maintain a user's attention and interest. Take a look at the list of frequent performance issues below, and you'll find that speed is a common feature in many of them −

  • Long Load Time − The load time of an application is the time an application takes for it to start. This should be limited to a bare minimum. While some applications are impossible to load in less than a minute, others can. If at all possible, the load time should be maintained to a few seconds.

  • Poor response time − The time it takes for a user to write down data into an application and for the application to reply to that input is known as response time. In general, this should be a relatively quick process. If a user is forced to wait too long, they will lose interest.

  • Poor scalability − When a software product can't handle the expected number of users or can't accommodate a wide enough range of customers, it's said to have poor scalability. To ensure that the application can manage the expected number of users, load testing should be performed.

  • Bottlenecking − A bottleneck is an impediment in a system that reduces the overall performance of the system.When coding flaws or hardware difficulties produce a decrease in throughput under specific conditions, this is known as bottlenecking. One defective section of code is frequently the source of bottlenecking. Finding the part of code that is causing the slowdown and attempting to correct it there is the key to resolving a bottlenecking issue. Bottlenecking is typically alleviated by either improving or adding additional hardware. CPU consumption is a common performance bottleneck.

    • Utilization of memory
    • Utilization of the network
    • Limitations of the Operating System
    • Use of the hard drive

Process of Performance Testing

The methodology used in performance testing can vary greatly, but the goal of the test remains the same. It can assist you in demonstrating that your software system meets pre-defined performance standards. It can also be used to compare the performance of two different software systems. It can also assist you in identifying areas of your software system that are causing it to perform poorly.

The procedure for performing performance testing is outlined below.

  • Determine your testing environment - Understand your physical test environment, production environment, and testing tools. Before you begin the testing process, learn about the hardware, software, and network settings that will be used. It will assist testers in developing more efficient tests. It will also aid in the identification of potential issues that testers may face throughout performance testing methods.

  • Determine the performance acceptance criteria- which include throughput, response times, and resource allocation goals and restrictions. Outside of these aims and limits, it's also vital to develop project success criteria. Because project specifications often do not offer a diverse set of performance benchmarks, testers should be given the authority to create performance criteria and goals. There may be none at all at times. Finding a comparable application to compare to is a useful way to set performance targets when possible.

  • Plan and design performance tests – Find out how end users' behavior is probably differs and select critical scenarios to test for all possible use cases. A range of end-users must be simulated, performance test data should be planned, and metrics should be defined.

  • Configuring the test environment - Before starting the test, make sure the environment is ready. Arrange tools and other resources as well.

  • Implement test design - Write performance tests in accordance with your test plan.

  • Run the tests - Run the tests and see them carefully.

  • Analyze, tune and retest - Consolidate, evaluate, and communicate test results by analyzing, tuning, and retesting. Then fine-tune and test again to determine if performance has improved or decreased. Stop when the CPU is the bottleneck, as improvements tend to get less with each retest. Then you might want to think about upgrading CPU power.

Tools for Performance Testing

There are many different types of performance testing tools on the market. The tool you use for testing will be determined by a number of parameters, including the protocol types supported, license costs, hardware requirements, platform support, and so on. A collection of commonly used testing tools is provided below.

  • LoadNinja
  • HP LoadRunner
  • JMeter

What applications should we test for performance?

Only client-server systems are subjected to performance testing. This means that any application that isn't built on a client-server architecture doesn't need to be tested.

Microsoft Calculator, for example, is not client-server-oriented and does not support multiple users, so it is not a candidate for Performance Testing.

Performance Test Cases Examples

  • When 1000 users access the website at the same time, make sure the response time is less than 4 seconds.

  • When network connectivity is slow, check that the Application Under Load's response time is within an acceptable range.

  • Before the application crashes, check the maximum number of users it can manage.

  • When 500 records are read/written at the same time, check the database execution time.

  • Check the application's and database server's CPU and memory utilization during high loads.

  • Check the application's reaction time under low, medium, moderate, and heavy load circumstances.

Vague words like acceptable range, heavy load, and so on are replaced by real values during the actual performance test execution. These metrics are set by performance engineers based on the application's technological landscape and business requirements.


Before marketing any software product, performance testing is required in software engineering. It guarantees consumer happiness while also safeguarding an investor's investment from product failure. Customer satisfaction, loyalty, and retention are frequently more than offset by the costs of performance testing.