Load testing basics (Postman) - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Load Testing Purpose

What is the main goal of load testing in Postman?

A To check how the system behaves under expected user load

B To find security vulnerabilities in the API

C To verify the correctness of API responses

D To test the user interface responsiveness

💡 Hint

Think about what happens when many users use the system at the same time.

Load testing measures system behavior under expected user load to ensure stability and performance.

❓ Predict Output

intermediate

Interpreting Load Test Results in Postman

After running a load test with 50 virtual users for 1 minute in Postman, the average response time is 1200 ms, and error rate is 0%. What does this indicate?

A The API is not responding because response time is too high

B The API is failing because response time is over 1000 ms

C The test failed because error rate should not be zero

D The API handles the load well with no errors and acceptable response time

💡 Hint

Consider what a 0% error rate means and if 1200 ms is acceptable.

An average response time of 1200 ms with zero errors means the API is stable and handles the load well.

❓ assertion

advanced

Correct Assertion for Response Time in Postman Load Test

Which Postman test script assertion correctly checks that the response time is less than 2000 milliseconds during a load test?

Postman

pm.test('Response time is less than 2000ms', function () {
    // Fill in assertion here
});

A pm.expect(pm.response.responseTime).to.be.below(2000);

B pm.expect(pm.response.time).to.be.above(2000);

C pm.expect(pm.response.responseTime).to.equal(2000);

D pm.expect(pm.response.time).to.be.belowOrEqual(2000);

💡 Hint

Look for the correct property name and assertion method to check less than a value.

The property pm.response.responseTime holds the response time in ms. The assertion to.be.below(2000) checks it is less than 2000 ms.

🔧 Debug

advanced

Identifying Load Test Script Error in Postman

Given this Postman test script snippet for load testing, what error will occur?

Postman

pm.test('Status code is 200', () => {
    pm.expect(pm.response.status).to.eql(200);
});

A TypeError because pm.response.status is undefined

B No error, test passes if status is 200

C AssertionError because status code is not 200

D SyntaxError due to arrow function usage

💡 Hint

Check the correct property name for status code in Postman response object.

The correct property for status code is pm.response.code, not pm.response.status (which returns the status text like "OK"). Expecting the status text to equal 200 causes an AssertionError.

❓ framework

expert

Configuring Load Test in Postman Runner

Which sequence correctly describes the steps to configure a load test with 100 virtual users running for 2 minutes in Postman Collection Runner?

A 1,2,4,3

B 1,2,3,4

C 1,3,2,4

D 2,1,3,4

💡 Hint

Remember that delay is the wait time between requests, and iterations control how many times the collection runs.

First select the collection, then open Runner, set iterations (to control number of runs), then set delay (to control wait time between requests).