API API Performance Testing 2

Question 1

What is the purpose of a 'spike test' in API performance testing?

Accepted Answer

Test how the API handles a sudden large burst of traffic

Answer

Spike testing sends a sudden, massive increase in load to see whether the API can recover and handle abrupt traffic surges.

Question 2

Which metric measures the percentage of API requests that fail during a performance test?

Accepted Answer

Error rate

Answer

Error rate is the percentage of total requests that return error responses (4xx or 5xx) during a performance test run.

Question 3

What does 'virtual users' (VUs) mean in the context of API performance tools like k6?

Accepted Answer

Simulated concurrent clients sending API requests

Answer

Virtual users (VUs) are simulated concurrent clients that each follow a test script, allowing testers to model realistic multi-user load.

Question 4

Which modern performance testing tool uses JavaScript-based scripts and is popular for CI/CD integration?

Accepted Answer

k6

Answer

k6 by Grafana Labs uses JavaScript test scripts and is designed for developer-friendly, CI/CD-integrated performance testing.

Question 5

What is the significance of setting a 'think time' in API performance test scripts?

Accepted Answer

Simulating realistic user delays between consecutive requests

Answer

Think time simulates the natural pause a real user takes between actions, making load patterns more realistic and avoiding artificial request bursts.

API - Testing Practice Test