Buyer's Handbook: Choose the best load testing software for your apps Article 3 of 4

What to look for in application load testing tools

Load testing tools help ensure an app is ready for prime time. But, with so many tools on the market, buyers must closely examine the products' features and their own environments.

Increasingly, organizations focus on how quickly they can deliver high-quality end-user experiences with software. Load testing is one way to help organizations achieve this speed, regardless of platform.

When they shop for application load testing tools, buyers must carefully review each tool's quality and features. Additionally, they should find tools that present results in a way that the software development team can analyze accurately and keep end users' needs in mind.

Load testing enables developers to evaluate the server, database, messaging systems, APIs or even the full engine that makes the application work. An application might pass QA testing and even user acceptance testing, but these evaluations typically occur on test systems, with a significantly limited number of users. With a suite of load tests, QA professionals can see whether the application's components will support the intended end-user experience in production.

Benefits of load testing

It's essential to verify the application performs as required under various traffic load conditions. For example, how does an app respond when it has over 100 concurrent users or 1,000 users clicking Save or Submit at the same time? Application load testing tools can confirm if the database can handle the input load or if the system gives the end user an endless spinner.

Load testing enables developers to evaluate the server, database, messaging systems, APIs or even the full engine that makes the application work.

Applications must scale up under increased demand -- sometimes over time and other times exponentially. If load tests confirm the application can handle normal customer loads, testers still must identify at what point the app, or its supporting components, will crash. The team must know where scalability pain points occur. Load and stress testing uncover these pain points and give developers an idea of what issues to fix before they become defects for end users, which saves time and productivity -- and keeps customers happy.

When an application fails a load test, an organization should use this information to devise a failover approach to keep the app operational. Applications need a failover approach that is undetectable to the end user. Load testing helps identify how far the application can go before failure, but it's just as important to make sure failover executes as intended. Successful failover plans save significant time and effort over trying to recover a failed system, and it helps customers trust the application is reliable.

Before you buy a load testing tool, examine the applications you plan to test. Details, such as coding languages and where the app will be hosted, should influence the buyer's decision. Know which IT staff members will use the tool and if additional staff or training are needed.

Open source vs. enterprise

As with many IT products, buyers must decide between commercial and open source tools.

If you have the requisite developer expertise to work within the open source project, then there's no cost to try an open source tool for application load testing.

If you don't have available development resources to customize and support an open source tool, commercial application load testing tools could provide the support and training an organization needs. A commercial tool still requires a team to manage the tool and the load testing, to accomplish testing goals in a reasonable time frame and to see ROI.

Scripting languages

Buyers should verify that application load testing tools work with the scripting languages developers use. If possible, secure a trial period for the tool to ensure the load tests will properly run with the code base without extra support or additional work.

It's essential that an application load testing tool supports many languages. An organization could always switch to a different language in the future. Before you buy, consider the likelihood that your developers will use another language in the next three to five years, and then make sure the tool supports those languages.

Resources and integration

Buyers must know how the tool will access test data and applications, whether that means on premises or via the cloud. Some tools offer virtual machines or another method to load data into the system.

Make sure the load testing tool can integrate with the overall development toolchain. If not, determine how much manual integration will be needed.

Buyers must also consider whether they have the available resources to support a tool in-house or if they require tool management from the vendor.

Reporting and metrics

Organizations must determine the level of reporting that they require for tests and how much effort they're willing to invest to obtain it.

Application load testing tools typically offer a range of premade reports to address most needs. If an organization desires more complex reporting, select a load testing tool that offers configurable reports.

IT staff should also feel comfortable with the tool's UI. If application load testing tools are inaccessible and not user-friendly, the organization will struggle to analyze results.

Application type

In many cases, load testing tools support all types of software applications. But buyers should still confirm that a tool can securely handle their specific type of applications, such as mobile- or web-based apps.

Editor's note

With extensive research into the load testing software market, TechTarget editors have focused this series of articles on vendors with considerable market presence and that offer load testing tools specifically for application development. Our research included Gartner, Forrester and TechTarget surveys.

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