An Introduction to Load Testing

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An Introduction to Load Testing

This specific type of performance testing will make sure that your software can stay operational under pressure.

· Performance Zone ·
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We have all been in situations while using software or a web applications where everything is running too slowly. You click a button and nothing is happening except a loader animation spinning for a seemingly infinite time.

The worst case is when end users face this kind of issue. This is bad news for the developer or the owner of the application. These are because of performance issues, and the only way this can be eliminated is through performance testing.

What is Performance Testing?

Performance testing is a type of software testing that focuses on the performance of a system under a specific load. It does not detect bugs or defects, but produces analytics based on benchmarks and gives the developer all the diagnostic information they need to access and eliminate performance issues and bottlenecks.

Types of Performance Testing

To get an understanding of how the application runs on the system of a user, four different types of non-functional performance testing are applied during the testing phase.

Load Testing

This type of performance testing is performed to diagnose the system’s behavior when the workload is increasing.

Stress Testing

Stress testing is conducted to find out how the application is working when the system is just at the boundary or already exceeding its workload capacity.

Endurance Testing

This type of testing finds out how the system is performing when continuously operated under a specific workload.

Spike Testing

Spike testing produces a diagnostic report of a system’s performance when the workload is increased suddenly at an elevated level.

In this article, we will focus on load testing.

Why Load Testing is Needed

Many popular sites that are extremely well-developed and well-maintained suffer from serious downtime issues when the network traffic increases all of a sudden. An example includes Encyclopedia Britannica. For a promotional campaign, they once provided access to their online database free of cost. For weeks, they were not able to maintain the performance of their website because of a huge number of visitors.

Load testing gives the developer and site owner confidence in their system’s performance and reliability. It also helps to detect the bottleneck by virtually creating a test scenario involving increased network traffic long before it actually happens in a production environment. It also provides complementary strategies to deal with performance management and monitors the application running at the production environment.

Prerequisites and Environments for Load Testing

Proper hardware and software configuration are needed to run load testing. A hardware platform should be well-configured with server machines, memory, processors, disks with high storage capacity, properly configured load machines and network. Software configuration is less complicated. A server software and operating system will do the job.

The primary measuring parameter of load testing is the system’s response time. Before the testing begins, you should gather the knowledge regarding whether the response time is already measured, whether it is applicable to a business process, whether it is achievable and justifiable and if it can be measured using a stopwatch or a tool.

Load Testing Life Cycle

The following process briefly describes how load testing is carried out.

  • First, a dedicated test environment is created.
  • Load testing scenarios are to be determined next. Each load testing scenarios should include proper maintenance of diagnostic data, a predictable number of users who will be accessing the system, connection speed of the networks to be used by end user, server configurations and finally, operating systems and browsers to be used by the end user.
  • The tester starts running the test cases and after proper monitoring, gathers all the metrics.
  • The results are then analyzed and procedures for performance improvement is suggested.
  • The system is fine tuned and the test cases are executed again

Popular Load Testing Tools

Apart from manual load testing, tools are used that can automate the process. Load testing tools may be developed in-house, and some open source tools are available which can be used when your budget is low. Apart from that, enterprise load testing tools are available that support multiple protocols and can simulate a huge number of users. 


NeoLoad is an enterprise-grade testing tool designed mainly for DevOps and Agile methodology. It provides the user with automatic design of test case scenarios, along with automatic maintenance and continuous analysis of data. NeoLoad can also be easily integrated with the testing ecosystem. It can be easily installed on servers like Jenkins and used along with functional tools like Selenium.


LoadView is a cloud-based platform that offers complete flexibility to the tester. It can test web APIs like SOAP, REST, JSON along with web servers and generates a series of GET and POST requests. It can also stimulate user behavior on critical functionalities like login, form submits etc. The tool is fully manager of cloud and available for a free trial.


WebLOAD is another enterprise-grade product that supports multiple applications, technologies, operating systems and network protocols. It is well known for its flexibility and the scripting gives you the privilege of smoothly executing complex test case scenarios.

Challenges in Load Testing

In spite of its multiple pros, certain cons are present as well. First of all, proper programming knowledge is required to operate load testing tools. Secondly, the tools can be a bit expensive since the pricing depends on the number of virtual users that the tool can support.

It can be said that performance testing is a mandatory phase before an application is deployed in the production environment. Especially when it comes to resolving bottlenecks and making the application stable and scalable, load testing is an important performance testing procedure that can help to detect the maximum functioning capacity of the application.

endurance testing, load testing, performance test tools, performance testing, spike test, stress testing

Published at DZone with permission of Arnab Roy . See the original article here.

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