Load testing basics (Postman) - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is load testing in software testing?

Load testing is a type of performance testing that checks how a system behaves under expected user loads. It helps find out if the system can handle the traffic without slowing down or crashing.

beginner

How does Postman help with load testing?

Postman allows you to create and run API requests and can simulate multiple users by running collections with different iterations or using integrations like Postman Collection Runner or external tools to generate load.

beginner

What is an iteration in Postman Collection Runner?

An iteration is one complete run of all requests in a Postman collection. Running multiple iterations simulates repeated user actions, which helps in load testing by increasing the number of requests sent.

beginner

Why is it important to monitor response time during load testing?

Monitoring response time shows how fast the system responds under load. If response time increases too much, it means the system may struggle to handle many users, which can cause poor user experience.

intermediate

What is a common limitation of using Postman alone for load testing?

Postman alone is not designed for heavy load testing with thousands of users. It is best for small to medium loads or functional testing. For large-scale load testing, specialized tools like JMeter or k6 are better.

What does load testing primarily measure?

A System behavior under expected user load

B User interface design quality

C Code syntax errors

D Database schema correctness

Load testing checks how the system performs when many users use it at the same time.

In Postman, what feature helps simulate multiple user requests?

A Response visualizer

B Environment variables

C Pre-request scripts

D Collection Runner with multiple iterations

Running a collection multiple times simulates repeated requests like multiple users.

Why might Postman not be suitable for very large load tests?

A It cannot send any requests

B It lacks the ability to simulate thousands of users efficiently

C It only works with web browsers

D It does not support API testing

Postman is great for functional and small load tests but not optimized for very large scale load testing.

What is an iteration in Postman Collection Runner?

A A saved environment

B A single API request

C One complete run of all requests in a collection

D A type of assertion

An iteration runs all requests in the collection once.

Which metric is most important to watch during load testing?

A Response time

B Font size

C Code indentation

D File size

Response time shows how quickly the system responds under load.

Explain how you would use Postman to perform a basic load test on an API.

Think about repeating requests and checking how the system responds.

Describe why monitoring response time is crucial during load testing.

Imagine waiting for a slow website when many people use it.

Practice

1. What is the main purpose of load testing in Postman?

easy

A. To check how many users the app can handle at the same time

B. To find syntax errors in API requests

C. To test the UI responsiveness of the app

D. To verify database schema correctness

Solution

1. Step 1: Understand load testing goal

   Load testing is about simulating many users to see how the app performs under stress.

2. Step 2: Match with Postman usage

   Postman can send multiple requests to simulate users, so it helps check app capacity.

3. Final Answer:

   To check how many users the app can handle at the same time -> Option A

4. Quick Check:

   Load testing = user capacity check [OK]

Hint: Load testing = many users at once [OK]

Common Mistakes:

• Confusing load testing with syntax checking
• Thinking load testing checks UI only
• Mixing load testing with database tests

2. Which Postman feature allows you to run multiple requests repeatedly for load testing?

easy

A. Postman Runner

B. Postman Console

C. Postman Monitor

D. Postman Collection Editor

Solution

1. Step 1: Identify Postman features for running requests

   Postman Runner lets you run a collection of requests multiple times.

2. Step 2: Match feature to load testing

   Running requests repeatedly simulates load, so Runner is the correct tool.

3. Final Answer:

   Postman Runner -> Option A

4. Quick Check:

   Repeated runs = Postman Runner [OK]

Hint: Use Runner to repeat requests [OK]

Common Mistakes:

• Choosing Console which is for debugging
• Confusing Monitor with scheduled tests
• Thinking Collection Editor runs requests

3. Consider this Postman Runner setup: you run 100 iterations with 10 requests each. How many total requests are sent?

medium

A. 100

B. 10

C. 1000

D. 110

Solution

1. Step 1: Understand iterations and requests per iteration

   Each iteration runs 10 requests, and there are 100 iterations total.

2. Step 2: Calculate total requests

   Total requests = 100 iterations * 10 requests = 1000 requests.

3. Final Answer:

   1000 -> Option C

4. Quick Check:

   100 x 10 = 1000 [OK]

Hint: Multiply iterations by requests per iteration [OK]

Common Mistakes:

• Adding instead of multiplying
• Confusing iterations with requests
• Ignoring requests per iteration

4. You tried to run a load test in Postman Runner but only one request was sent repeatedly instead of the whole collection. What is the likely mistake?

medium

A. You forgot to save the collection

B. You selected a single request instead of the full collection

C. You used Monitor instead of Runner

D. You set iterations to 1

Solution

1. Step 1: Analyze the problem

   Only one request runs repeatedly, not the whole collection.

2. Step 2: Identify cause

   This happens if you run a single request in Runner instead of the entire collection.

3. Final Answer:

   You selected a single request instead of the full collection -> Option B

4. Quick Check:

   Single request run = wrong selection [OK]

Hint: Always select full collection for load test [OK]

Common Mistakes:

• Thinking iterations = 1 causes this
• Confusing Monitor with Runner
• Assuming saving fixes request selection

5. You want to perform a heavy load test beyond Postman's Runner limits. Which approach is best?

hard

A. Increase iterations in Postman Runner to 10,000

B. Use Postman Console to debug requests

C. Run Postman Monitor continuously for 24 hours

D. Use Newman in combination with a load testing tool like Apache JMeter

Solution

1. Step 1: Understand Postman Runner limits

   Postman Runner is good for basic load but not for very heavy or distributed load testing.

2. Step 2: Identify best heavy load testing method

   Newman can run collections from command line and can be integrated with tools like JMeter for heavy load.

3. Final Answer:

   Use Newman in combination with a load testing tool like Apache JMeter -> Option D

4. Quick Check:

   Heavy load = Newman + load tool [OK]

Hint: Combine Newman with load tools for heavy tests [OK]

Common Mistakes:

• Trying to increase Runner iterations too high
• Using Monitor for load testing
• Using Console for load testing