Demystifying Performance Testing: A Complete Guide

You might have experienced several occasions wherein an application suffered a failure that could have been avoided with effective performance testing. Many applications or websites crash during times of peak load. Performance testing is critical for any business as it gives vital information on the stability, scalability, and reliability of your application.

What is Performance Testing?

Performance testing is a type of software testing that is used to test the speed, responsiveness, and behavior of the software under a workload. Performance testing is not about finding software bugs or defects.

Software organizations leverage performance testing to identify the business-critical performance-related bottlenecks, and it gives the developers the key information required to remove these bottlenecks.

Significance of Performance Testing

Performance testing not only provides vital information to the stakeholders regarding their application’s speed, stability, and scalability but also unravels the key issues that need to be resolved or improved before the product goes to the market.

Here are some of the key reasons why organizations must go for performance testing –

Give your customers speedy performance

A slow application or website can become a big turn down for your customers and the business. Performance testing can help enhance the speed and performance of the application, which gives users a smooth experience and engage them for long

Make sure your app remains sturdy at all times

It is important for companies to ensure that their apps remain sturdy and robust even at the most critical times, such as cyber-attacks, network issues, or virtual threats

Generate more revenue with a fast application

The common rule for all the websites and applications is that the faster the application, the higher the revenue. Faster apps get repeated visitors and better traction in the long run

Remove glitches before your app hits the market

Performance testing ensures that your application performs exactly the way it is expected. Different types of performance tests help remove the critical glitches on time and resolve the risks that may appear in the real world scenario

Enhanced scalability

Considering the rising challenges in the digital space, companies need to build apps that are scalable in the future. Companies can leverage performance testing to expose the possible vulnerabilities and the areas where the software needs to be strengthened to get more scalable

Performance tests help determine the behavior of the app and whether the server responds to the user with the data in a specified time gap. It also helps to analyze the performance and behavior of the API under heavy load

Boost your app with stability and dependability

Your application needs to be stable and give desired results despite undergoing changes in its features. Some specific performance tests can help analyze if there is any disruption caused due to a change in the code of the application

Types of Performance Testing

Here are some of the major performance test types and how they are used to create an overall effective performance test

Load Testing

Load testing is a type of performance testing that helps in determining a system’s performance under specific workload conditions. The workload could mean concurrent users performing some actions at the same time or a number of transactions undergoing simultaneously. It is the bread and butter of every load tester that helps test how software behaves with a large number of users and analyze the response time received under different scenarios.

The objective of load testing is to evaluate an app’s performance under a high number of users and measure the results to validate whether the requirements are being met or not. It is a crucial part of the development process as it helps ensure that your software will provide a smooth user experience and get good customer feedback.

Load testing helps in evaluating –
  • The maximum operational capability of the application
  • The average number of users the software can support at any given point in time
  • The durability of the software when challenged with a peak user load
  • The readiness of the current infrastructure can seamlessly support a user’s interaction with the software

An example of Load testing could be a large number of concurrent users performing a specific number of transactions within the given time. Load testing helps in giving the response times of all the business-critical transactions.

Stress Testing

Under stress testing, the software is kept under heavy load conditions in order to determine the components that are failing first. It is very much similar to load testing with a minor difference that we are applying a higher than expected workload in stress testing to analyze how the system is behaving when exposed to high stress. It induces failures deliberately to analyze the risk involved at the breaking points. Stress testing is ideal not only to prepare for the unexpected but also to find how far a system can be pushed.

Stress testing is ideal in identifying the breaking point of the application and analyzing how strong is the data processing capabilities of the application. It can also be used to find the key data corruption issues and hardware issues. It involves a steady increase in the load to see the point where the system under test begins to breach its non-functional requirements. This breaking point can be used to describe the capacity of the given system.

Most of the websites and applications experience a sudden increase in the number of visitors during holidays, promotions, or festive seasons and incompetence in handling such a sudden rise in the number of users could lead to a significant loss in both revenue and the company’s image. Stress testing plays a key role in being prepared for such an increase in the load and handling the situation effectively.

Spike Testing

One of the key aspects for software companies is to maintain the performance of the software at any cost. But when there is an extremely high load on a system, there can be multiple issues to deal with. The standard testing method might miss or can’t address the bad to worse case scenarios. Spike testing comes in handy during these times for testing these scenarios, which help in minimizing the key issues significantly.

Spike testing is used to determine the ability of the application to withstand sudden spikes in traffic and to evaluate the behavior of the application under sudden rise or fall in user load. It is usually performed by suddenly increasing the load generated by a large number of users. Another key objective of spike testing is to determine the recovery time.

Spike testing helps in determining
  • The behavior of the software application under the frequent load change
  • The system’s failure under extreme load
  • The recovery time between two spikes
  • The performance of the system under abruptly changed load

You should also be aware of the main disadvantage of spike testing, which is – it involves an expensive testing process as it requires setting up special test conditions. However, it gives a positive return on investment in the long run.

Endurance Testing

Endurance testing is a type of software testing wherein an app is tested under high load over a long period of time to check and analyze the behavior of a software application under extreme conditions. The main objective of endurance testing is to find potential performance issues which other performance tests can’t find. For instance, endurance testing can easily detect memory leak issues that can’t be detected during volume or stress testing.

Endurance testing is generally performed at the last stage of the performance run cycle and takes a long time as the main objective of performing it is to check the performance of the software over prolonged use. But it has its fair share of challenges described below –

Challenges in Endurance Testing

  • Endurance testing is difficult to carry out as it is a long and time-consuming process
  • It can’t be carried out manually and requires an automation tool and a level of knowledge and expertise of the tool
  • It is crucial to isolate the test environment from the productions environment, else the network failures in the endurance test can affect the working system and can lead to permanent data loss
  • Another key challenge is to determine how much load is worth applying

Volume Testing

Volume testing is a type of non-functional testing that is performed to analyze the performance of the software or the system by increasing the volume of data in the database. Volume testing is a type of performance testing that is also known as flood testing.

Objectives of Volume Testing

  • Volume testing helps in identifying the capacity of the software and predicting the amount of data the software can possess
  • Helps understand whether scaling up or scaling down is the right strategy or not
  • Volume testing ensures there is no data loss with the increase in the size of the database and the pressure on the software
  • It helps in ensuring that the system response speed remains high despite a high amount of data sharing by the users
  • One of the key objectives of conducting volume testing is to find the issues that only show up when there is an increase in the data load, such as high response time, security exploits, and system failures

Volume testing not only helps you analyze how fit your software is for the real world but also saves a significant amount of money that otherwise would be spent on maintenance purposes. However, the testing is associated with several challenges, such as populating a database, analyzing the data types and the connections between them, and handling the large data volumes.

Scalability Testing

Scalability testing is testing the performance or behavior of software while scaling up or scaling down or measuring its capability to scale up or scale down in terms of its non-functional capability. It is a type of performance testing that comes under non-functional testing. The main objective of the scalability testing is to control how the software behaves and balances with an increase in the workload and at what point it stops scaling.

Types of Scalability Testing 

Upward Scalability Testing – Upward scalability testing is primarily used to identify the maximum capacity of an application. It can be used to increase the number of users on a specific scale until the crash point is reached

Downward Scalability Testing – The other type of scalability testing is downward scalability testing, wherein the number of users is decreased in a particular interval until the goal is achieved. It plays a significant role in identifying critical bugs or bottlenecks.

Scalability testing helps save a significant amount of time and money as it helps in identifying the cause of a majority of performance issues in software during the testing phase. Additionally, the use of scalability testing ensures the accurate functioning of the software while completing the requirements of the end-users without any issues. However, sometimes the scalability testing fails to find the functional faults as the test environment is not always exactly similar to the production environment.

Process of Performance Testing

Identifying Test Environment

Before initiating the performance testing, it is crucial to know your physical test environment, production environment, and the testing tools to be used to carry out the testing processes. Having a clear understanding of the software, hardware, and network configurations beforehand helps the testers in creating more efficient tests and identifying possible challenges that could emerge during the performance testing processes.

Determining Performance Criteria

It is crucial to identify the success criteria of the project and set performance goals and constraints for response times and resource allocation. Testers should be encouraged to set these performance criteria and goals, as most of the time, the project specifications might not have a wide range of performance benchmarks.

Planning and Designing Performance Tests

Carefully planning and designing performance tests is crucial to effectively plan performance test data and identify the key metrics to be gathered. It helps in identifying key scenarios that should be tested for all the possible use cases and determining how the user might vary among the end-users.

Configuring Test Environment

Configuring the test environment involves preparing the test environment before test execution in addition to arranging tools and other resources.

Implementing Test Design

The step includes creating performance tests according to your test design.

Running Tests

It involves executing and monitoring the tests.

Analyzing, Fine Tuning, and Retesting

The process includes analyzing test results and then fine-tuning followed by retesting to check for any improvement or decrease in the performance.

Performance Testing Best Practices

Here are some of the best practices for conducting performance testing –

  • Test early, test often – Many companies take performance testing as an afterthought and bring it late in the development cycle. It should be proactive instead, following an agile approach and using it throughout the entire development life cycle
  • Build a performance model – It is ideal to build a performance model for your system and define performance goals such as scalability, response time, user satisfaction score, and acceptable performance metrics
  • Create realistic tests – It is crucial to accurately measure how your app performs in a real-world scenario. Build your tests with randomness and variability in mind and ensure that simulation doesn’t start with a zero-load situation
  • Regularly report and analyze the results – Performance test reports are equally important as execution as they communicate the behavior and performance of your app to the developers and project owners
  • Test all resources and layers of the stack – An app relies on all layers of the stack, and hence performance of all the layers and each component within each layer should be tested individually and as a whole

Investing in agile performance testing is important for the success of software organizations. It is vital to have an effective performance testing strategy in place to highlight the business-critical performance issues, whether it is related to database, network, software, bandwidth, or hardware.

Automation of performance tests can add immense value to the application testing process. There are many automation testing tools available in the market that can help analyze all the aspects of your application