Performance Testing with Postman

Introduction

Performance testing checking out is crucial for ensuring that an application or API can manage the needs positioned on it by customers. It entails evaluating diverse elements inclusive of responsiveness, stability, and scalability. Even as Postman is widely known for its API testing skills, it may also be used to conduct basic overall performance trying out, particularly whilst combined with different gear and techniques.

Table of Content

• What is API Performance Testing?
• Why Use Postman for Performance Testing?
• What Are The Benefits of API Performance Testing?
• Steps to Run Performance Testing
• Compare Two Performance Runs
• Conclusion

What is API Performance Testing?

API general overall performance testing checking out is a form of software program checking out that evaluates the responsiveness, balance, and scalability of an application Programming Interface (API) beneath various conditions. The purpose is to make sure that the API plays correctly and reliably whilst subjected to unique degrees of load and stress and to find out and remedy overall performance-related problems in advance before the API is deployed in manufacturing surroundings.

Why Use Postman for Performance Testing?

Postman is widely known for its API improvement and trying out competencies, but it can also be used for overall performance testing, even though it won't be the primary device for this motive. Here's why you may use Postman for overall performance testing:

1. Ease of Use

Postman's consumer-pleasant interface makes it easy for users who may not be familiar with extra complicated performance testing tools. You may quickly create and run tests without tremendous setup.

2. Rapid Prototyping

It's clean to create and regulate requests in Postman, permitting you to prototype and test distinct situations or endpoints quickly. This will be useful in performance testing while you want to iterate rapidly.

3. Automated Testing

Postman collections and scripts permit for automation of API tests, which may be extended to performance trying out scenarios. You could install computerized tests to run at specified periods or as part of a CI/CD pipeline.

4. Built-in Scripting

Postman supports JavaScript for writing pre-request and test scripts. This flexibility allows you to implement custom logic for performance tests and measure response times directly within Postman.

5. Response Time Monitoring

You can monitor and assert response times in Postman scripts, making it possible to get a basic idea of performance characteristics. This can be helpful for initial testing or smaller-scale performance assessments.

6. Integration with CI/CD Pipelines

Postman integrates well with CI/CD tools like Jenkins, GitHub Actions, and others. This integration allows for automated performance testing as part of the deployment pipeline.

7. Request and Environment Management

Postman's environment and variable management features make it easier to test APIs under different conditions and configurations, which can be valuable for performance testing scenarios.

8. Basic Load Testing

While Postman is not designed for high-scale load testing, it can handle some level of load testing by running collections with multiple iterations or using the Postman Collection Runner.

What Are The Benefits of API Performance Testing?

Here's a deep dive into the benefits of API performance testing:

• Identifying performance bottlenecks:Overall performance trying out enables pick out regions of the API that can reason slowdowns beneath heavy usage, bearing in mind centered optimizations.
• Ensuring scalability: By testing performance under different load levels, API performance testing ensures that the API can handle increased traffic and users without performance degradation.
• Enhancing user experience:Performance testing checking out helps ensure that APIs reply quickly to personal requests, which is important for effective user enjoyment. Gradual APIs can lead to consumer frustration and reduced delight.
• Proactive issue detection: With the aid of carrying out performance tests, you could proactively cope with capability performance troubles earlier than they impact customers or the software.

Steps to Run Performance Testing

1: How to run tests

Step 1: Create your collection and add APIs you want to test first.

Step 2: Add assertions.

• You should use assertions in load tests as it verifies that a server returns an expected result.
• Select the Tests tab to add assertions. Verifying request responses in Postman is done by writing tests in JavaScript.
• There are several approaches to implementing assertions in the Postman, each serving a unique purpose. The main assertion types include:
• Status code assertion
• Response Body Assertions
• Header Assertions
• JSON Schema Assertions
• XML Assertions

Step 3: Select the Postman collection you are planning to execute performance testing and click on Run collection.

Step 4: Select the Performance tab on the right. There will be 3 options:

Load profile: The intensity of the load during the test’s duration.

• Fixed: All virtual users will repeatedly run the collection in parallel.
• Ramp up: The number of VUs slowly increases from the initial load to the maximum.
• Speak: the number of VUs increases from the base load to the maximum and returns to the base load.
• Peak: The number of VUs increases from the base load to the maximum, holds steady, then decreases back to the base load.

Max Virtual Users: How many users will simultaneously call the collection.

Test duration: How long the test will last (in minutes).

2: Analyze test result

After the execution runs, you will get a nice graph with detailed results. This report provides the following basic metrics:

• Total requests sent
• Requests/second (throughput)
• Avg response time
• Error rate

Compare Two Performance Runs

Usually, to compare results, performance tester base on the Summary Statistics and look for differences between response time of the test results. Though this is a straightforward approach, it does not help you see the whole picture of the differences between the test runs.

Consequently, to understand how the performance of your API has changed over time, you can compare performance runs by using the built-in feature "Compare runs". Select 2 runs to compare, and Postman will visualize differences between the 2 runs like this:

Postman vs JMeter

Feature	Postman	JMeter
Plans and Pricing	Free for individuals and small teams (upto 3 users).	Avaialble for free
Integrations	Azure Pipelines, Bitbucket Pipelines, CircleCI, GitHub Actions, GitLab CI/CD, Jenkins, Travis CI	Jenkins, Apache Maven, InfluxDB and Grafana, Apache Kafka
Community Support	It has a vast user community, tutorials, and community support.	It has a large and active community of users and contributors, with many resources and forums available.
User-Friendliness	Postman gives a person-friendly interface.	It is complex for beginners, but it has many resources and tutorials available to help users get started.
Test Scripting	Postman tests are run using JavaScript.	Beanshell, Groovy, JavaScript or JEXL Groovy have become the recommended scripting language.
Report	Postman offers a quite basic report.	JMeter supports dashboard report generation to get useful graphs and statistics separately, it is easy to track.
Max Virtual Users	You can simulate up to 100 virtual users on a free plan. Also, upgrade to a paid plan for testing with more virtual users.	Doesn’t have a limit on virtual users.

Conclusion

Postman has limitations, but it is impressive that you can go from nothing to an easy performance test in minutes. There is sometimes a need to run performance tests immediately, without researching solutions, coding, and training testers to use cumbersome tools. On numerous occasions, I have found Postman to be the remedy to such a problem.

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About Author

Ashok Makwana is a seasoned Quality Assurance professional with a passion for continuous learning. He started his journey as a QA in September 2020 and embraced challenges as opportunities for growth. His drive to excel led him to aspire to become a Lead QA Manager, exemplifying dedication and expertise in his field. With a proactive approach and a thirst for knowledge, Ashok Makwana embodies the spirit of lifelong learning and achievement in quality assurance.