How to do Performance Testing for Web Applications - A Comprehensive Guide

Web applications have evolved seismically over the past few years. From simple web applications with limited interactive elements and a single server and client, web applications have become more dynamic and require several servers to generate a single interaction.

Read: Root cause analysis for software defects

The initial simple static and limited websites with minimal interactions were featured by service-side rendering and desktop application testing, where testers relied mostly upon manual and exploratory testing. However, the new interactive applications coming into the space with simple content creation, dynamic HTML, client-side rendering with DOM manipulation and iQuery, and QTP (UTF- Unified Functional Testing), have changed the testing requirements significantly. Along with the evolution of web applications, web app testing and monitoring solutions need to fit perfectly as well. 

Moreover, the focus on customer satisfaction is more than ever today, urging organizations to rigorously test the applications to ensure 

What is performance testing?

Performance testing is software testing that determines how a web application performs under a specific workload. It assesses speed, scalability, reliability, and stability to ensure the application delivers a smooth user experience, even during peak traffic. The main objective is identifying performance bottlenecks before the application is launched and ensuring it meets the desired performance criteria.

What are the key metrics to track in web application performance testing?

Tracking key performance metrics is crucial for evaluating a web application’s efficiency. Here are the essential metrics to monitor:

1. Response Time: The time a server takes to respond to a client request.
2. Throughput: The number of requests handled by the application per second.
3. Error Rate: The percentage of failed requests out of the total requests.
4. Latency: The delay between a user's request and the server's response.
5. CPU and Memory Usage: How much CPU and memory resources are consumed during peak load.
6. Concurrent Users: The number of users simultaneously accessing the app.
7. Peak Load: The maximum number of concurrent users the application can handle before performance degradation.

Web applications performance testing process

The process for performance testing web applications can be broken down into several stages:

1. Requirements Analysis: Identify the performance requirements, such as load capacity, peak user load, and response time targets.
2. Test Environment Setup: Create an environment that mimics the production setting as closely as possible to yield accurate test results.
3. Test Plan Creation: Develop a detailed plan outlining the test scenarios, workloads, and tools for testing.
4. Script Development: Use performance testing tools to create scripts that simulate user interactions.
5. Test Execution: Run the tests under different load conditions, like normal and peak load, and stress conditions, to gather performance data.
6. Result Analysis: Analyze the test results, looking at response time, throughput, and error rates to locate any performance issues.
7. Optimization: Use the insights gathered to optimize the application, fix bottlenecks, and improve performance.‍
8. Re-testing: After making improvements, run the tests again to ensure the performance issues are resolved.

The new web app testing environment

The modern development environment is in constant flux, where developers introduce code changes multiple times in a day, and automated processes are leveraged to build and test the web app proactively.

What is web application architecture?

Web application architecture is the layout that displays the interactions between the application components, middleware systems, user interfaces, and databases. These interactions allow a number of apps to work concurrently.

Once the users open a website, the server transmits specific information to the web browser to address the web clients' requests. Users might look for web resources or files such as HTML or PDF through the server, and the required information appears. Following this, the interaction begins between the user agent and the web page.

Until recent years, the focus on testing the apps from the perspective of the consumers' expectations and requirements wasn't as extensive as today. Application developers focused immensely on the functional testing of the applications to verify that each attribute of the application functions as expected.

Let's understand the need for functional testing!

What is functional testing of web applications?

Functional testing refers to testing that helps verify that every function of the software application operates in conformity with the requirement specification. This primarily involves black box testing and doesn't rely on the application's source code.

Each functionality of the system is tested by providing a suitable input, verifying its output, and comparing the actual and expected results. This testing method involves assessing the user interface, APIs, client/ server applications, and functionality of the application under test. 

How does functional testing benefit?

Below mentioned are a few benefits of functional testing for software quality assurance: 

Defect-proofing

Functional testing helps detect any minor bugs and errors in the application to improve the product's functioning. Consequently, the software quality enhances significantly as it is free of all known defects and vulnerabilities.

Check: Saving Test Data to Make Debugging Easier

Functionality Enhancement

Application flaws can be easily identified through functional testing. If the application's coding or qualities improve, the developers can make the necessary modifications per the test results. This ultimately helps to improve the application's functioning. Further, the functional test provides insight into the application's ability to perform as per expectations.

Security improvements

Functional testing attributes help to assess and assure the software's security. It provides a conclusive assessment of the application's suitability for storing users' sensitive data.

However, testing modern web applications is never limited to functional testing alone and requires extensive testing of non-functional aspects, including performance, usability, reliability, and much more.

With the prominent transformation of web applications, consumer demands have also escalated. Consumers today are getting accustomed to flawless performances of applications and great digital experiences, as a result of which organizations are increasingly focusing on performance testing of web applications. 

What is website application performance testing? 

Web application performance testing refers to a subset of performance testing that specifically evaluates web applications to determine if the web app performs as expected in terms of its speed, web server response time, network latency, database queries, and much more. Web app performance testing enables businesses to optimize their web applications and ensure flawless user experiences.

Enterprises are executing web performance testing more and more to provide accurate information regarding the readiness of the web apps through testing the website and monitoring the server-side application. Web performance tests are primarily run by simulating load close to real conditions to evaluate whether the app can support the expected load and help developers identify the performance bottlenecks to help resolve them and improve the overall performance.

What is performance testing?

Failing to ensure optimal performance of web apps can cost organizations huge financial losses, compromised brand reputation, low conversion, and poor CSAT.

The key reasons why organizations should conduct web app performance testing are—

• Identifying performance bottlenecks: Bottlenecks like slow response rates, poor scalability, system downtime, battery drains, and so on can lead to negative user experiences or even software crashes. With careful performance testing, testers can efficiently pinpoint performance issues and explore cost-efficient techniques to resolve such issues before the product rolls out in the market.

• Ensuring stability across multiple platforms: Users access web apps from different browsers, devices, and operating systems. These diverse platforms have varying impacts on attributes like load time, response time, and other key performance metrics. Therefore, testing teams leverage effective performance testing approaches to ensure that the apps perform seamlessly across different platforms and offer flawless user experience.

• Verifying compliances: The data obtained as the outcome of the performance testing is crucial for all project stakeholders. These help to achieve compliance with SLAs, contracts, and current regulations and enable teams to create a configuration that delivers high-quality performance without compromising business objectives.

• Discovering ideal configuration for applications: Performance testing of web apps assists in predicting how different system resources are required to maintain the applications. Post the test, the project teams can determine the configuration that delivers high-quality performance with no compromises to business objectives.

• Reducing revenue losses: By identifying the risks and vulnerabilities of system shutdowns and fine-tuning the web app, project teams can reduce the chances of downtime, thereby enabling them to reduce the cost associated with it.

Also see: Calculation of ROI in Mobile App Automation Testing

Different types of performance testing for web applications

1. Load testing: Measures the application's ability to handle expected user loads. It helps identify the maximum operating capacity and performance degradation under heavy traffic.
2. Stress testing: Evaluate the application's performance under extreme conditions, often beyond its normal operational capacity. This helps identify the breaking point and ensures the system can recover gracefully from failures.
3. Endurance testing: Assesses the application's stability and performance over an extended period. It ensures the system can handle continuous usage without memory leaks or performance degradation.
4. Spike testing: Tests the application's reaction to sudden, sharp increases in load. This is crucial for applications that experience unexpected traffic spikes, such as during sales or promotions.
5. Scalability testing: Evaluates the application's ability to scale up or down in response to varying load conditions. This testing ensures that the system can grow or shrink in capacity without affecting performance.‍
6. Volume testing: Assesses the system's behavior when handling large volumes of data. This is important for applications that process or store significant amounts of information.

Modeling real-life scenarios for web apps

To test the exact behavior of an app, it is essential to model the test accurately and consider the following attributes: 

• Testing across geographies: Typical performance tests conducted in labs might give a picture far from the real scenarios. Actual applications perform across different locations, including remote areas. Hence it is essential to consider testing across different locational conditions.

• Testing sleep times: Project teams must focus on evaluating apps and their behaviors across different time zones and at different times of the day. Web apps are not meant to be limited to particular hours during the day and therefore need to offer a similar experience at any point in time.

• Usage patterns: Every web app has diverse users accessing it differently. Some apps have peak visits once every day, while some apps witness concentrated visits during specific occasions. For instance, any brand promoting a campaign for Christmas shopping will have a sudden peak of users near the festival's date, or a brand selling goodies related to FIFA might have users during the World Cup season.

Please check: 10 Ways to Accelerate the Software Testing Cycle

What are the best practices for optimizing web application performance?

1. Preparing the performance testing environment

In this stage, the QA team and software developers should work towards defining the performance acceptance criteria and objectives of the testing. This involves determining the performance metrics that need to be measured, what kind of workload will be used in the testing environment, and how to simulate the real-world user environment as close to the real scenario as possible. Additionally, it is important to define the thresholds for each metric to understand when the application is not performing as expected and requires further improvement.

Once the performance objectives are determined, the test environment should be set up. 

Following this, the team should plan the performance test data and configure the test tools. The ideal test environment often includes network configurations, hardware, and software tools.

Read: Choosing the right tools for automated mobile app testing

Organizations should carefully involve both software developers and testing engineers in this stage to establish a fully functional and effective test environment.

2. Designing the test cases & scenarios

After an effective testing plan is created and the environment is set, teams should focus on designing the test cases and scenarios to ensure that the performance objectives set at the beginning are met during the actual testing process. In this stage, the testers can identify and predict all the situations users may need any help or support with. Hence, the test cases and scenarios must be designed based on the user stories and use cases of the web application to ensure that all potential user actions are covered.

3. Executing the test 

The effectiveness of the test plan creation and environment configuration significantly impacts the success of test execution. The tests should be conducted on a regular basis and in different environments (such as development, staging, and production) to make sure that the web app can work stably and smoothly in all possible scenarios. This stage can be broken down into two stages:

Stage 1: This involves conducting actual performance testing aligned with the test design. This phase offers an opportunity to identify errors and bugs related to the app's speed, responsiveness, and stability.

Stage 2: After the tests are completed, the team analyzes results with detailed graphs and reports to identify issues across the entire process. This allows developers to find specific solutions for the issues and determine which codes of architecture require modifications to help the web app perform better with different workloads.

4. Making improvements

After analyzing the performance data, testing teams should try to make adjustments to the codes and architecture to improve and optimize the web app's performance. This phase requires the software developers and testing engineers to work collaboratively, where the former needs to make necessary tweaks to the code while the latter needs to retest the web app to verify if the changes are effective.

5. Deploying and monitoring production

In the concluding phases of the web app performance testing, the teams deploy the web app in the production environment and monitor the performance regularly to check for fluctuating performances. Repeated tests help to detect any potential flaw in terms of the web app's speed, responsiveness, and stability to ensure immediate remediation steps.

Check: What is Continuous Monitoring in DevOps?

How HeadSpin works with organizations to troubleshoot performance issues of their web apps

HeadSpin works closely with organizations across multiple industries to extend its data-driven testing platform that helps optimize the performance of web apps by identifying and resolving performance issues across different devices, apps, and networks. HeadSpin's advanced capabilities help brands ensure the perfect performance of their applications and deliver flawless user experiences.

HeadSpin allows you to: 

• Continuously monitor and optimize the quality of experience

• Capture critical performance metrics, including—

• Experience specific KPIs - audio, video, mobile & more
• KPI correlation across different applications and touchpoints
• Custom-defined interaction KPIs specific to your app

• Obtain real-world performance data from several devices across 50+ locations, real SIM-enabled devices by leveraging HeadSpin's Global Device Infrastructure

• Leverage advanced AI capabilities to automatically surface performance issues

• Perform root-cause analysis of user-impacting performance issues,

• Obtain issue predictions based on historical data

Wrapping up

As web applications evolve with time and aim to cater to dynamic consumer expectations, aligning the testing approaches accordingly to meet the testing needs efficiently is essential. Testing methodologies have become more advanced in recent years, aiming to verify that applications operate perfectly and ensure flawless user experiences, improving brand reputations and building robust client relationships. 

FAQs

Q1. How does performance testing impact the overall development cycle of a web application?

Ans: Performance testing helps identify potential performance issues early in the SDLC, allowing developers to address them before the application is deployed. This proactive approach reduces performance problems in production, leading to a more stable app and a better user experience.

Q2. Why is it important to test web applications under different network conditions?

Ans: Testing web applications under different network conditions is important because users access applications from various locations and devices, each with different network speeds and latencies. By simulating different network conditions, performance testing can identify how the application behaves in real-world scenarios and ensure it delivers a consistent user experience.

Q3. What role does performance testing play in Agile and DevOps methodologies?

Ans: In Agile and DevOps methodologies, performance testing is crucial in ensuring that continuous integration and delivery processes deliver high-quality, high-performing software. By integrating performance testing into the development pipeline, teams can quickly identify and resolve performance issues, maintaining the application's performance standards throughout the development lifecycle.