Load testing concepts in Testing Fundamentals - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define the main goal of load testing.

Testing Fundamentals

def load_testing_goal():
    return "To measure system performance under [1] load"

Drag options to blanks, or click blank then click option'

Aminimal

Bno

Cnormal

Dheavy

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 'normal' load instead of 'heavy' load.

Load testing aims to measure how a system performs under heavy load, simulating many users or transactions.

2fill in blank

medium

Complete the code to specify the tool commonly used for load testing.

Testing Fundamentals

def common_load_testing_tool():
    return "[1]"

Drag options to blanks, or click blank then click option'

AJMeter

BSelenium

CPostman

DGit

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing JMeter with Selenium or Postman.

Apache JMeter is a popular open-source tool used for load testing web applications.

3fill in blank

hard

Fix the error in the code that sets the number of virtual users for load testing.

Testing Fundamentals

virtual_users = [1]  # Number of users to simulate

Drag options to blanks, or click blank then click option'

A"ten"

B10

Cuser_count

DNone

Attempts:

3 left

💡 Hint

Common Mistakes

Using a string like 'ten' instead of number 10.

The number of virtual users must be an integer, so 10 is correct. Using a string or None will cause errors.

4fill in blank

hard

Fill both blanks to create a dictionary that stores response times for each user during load testing.

Testing Fundamentals

response_times = {user[1]: [2] for user in range(1, 6)}

Drag options to blanks, or click blank then click option'

A_id

Bget_response_time(user)

Cuser

Duser + 1

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'user' as key without '_id', or using 'user' as value instead of response time.

The key should be 'user_id' to identify each user, and the value should be the response time from a function call.

5fill in blank

hard

Fill all three blanks to filter response times greater than 200 ms and create a summary dictionary.

Testing Fundamentals

slow_responses = {user[1]: time for user, time in response_times.items() if time [2] [3]

Drag options to blanks, or click blank then click option'

A_id

B>

C200

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>' or wrong key name.

We use 'user_id' as key, filter times greater than (>) 200 milliseconds to find slow responses.

Practice

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

easy

A. To verify the correctness of business logic

B. To find security vulnerabilities in the system

C. To test the system's user interface design

D. To check how the system behaves under expected user loads

Solution

1. Step 1: Understand load testing goal

   Load testing is done to see how a system performs when many users use it at the same time.

2. Step 2: Compare options with load testing purpose

   Only To check how the system behaves under expected user loads matches this goal. Other options relate to security, UI, or logic testing, which are different types.

3. Final Answer:

   To check how the system behaves under expected user loads -> Option D

4. Quick Check:

   Load testing = check system under expected load [OK]

Hint: Load testing checks system performance under user load [OK]

Common Mistakes:

• Confusing load testing with security testing
• Thinking load testing checks UI design
• Mixing load testing with functional correctness

2. Which of the following is the correct syntax to start a load test using a common tool script named load_test.sh in a terminal?

easy

A. run load_test.sh

B. start load_test.sh

C. bash load_test.sh

D. execute load_test.sh

Solution

1. Step 1: Identify common shell command to run scripts

   In Unix-like systems, bash script.sh runs a shell script.

2. Step 2: Check other options for correctness

   Commands like run, start, or execute are not standard shell commands to run scripts.

3. Final Answer:

   bash load_test.sh -> Option C

4. Quick Check:

   Run shell script = bash script.sh [OK]

Hint: Use 'bash script.sh' to run shell scripts in terminal [OK]

Common Mistakes:

• Using non-existent commands like 'run' or 'start'
• Forgetting to specify the shell to run the script
• Confusing script execution with program installation

3. Consider this simplified load test script output summary:

Users simulated: 100
Average response time: 2.5 seconds
Error rate: 0%

What does this output tell us about the system's performance?

medium

A. The system handles 100 users with no errors but response time is moderate

B. The system has errors and slow response time

C. The system cannot handle 100 users

D. The system response time is very fast

Solution

1. Step 1: Analyze the output values

   100 users were simulated, error rate is 0%, so no errors occurred. Average response time is 2.5 seconds.

2. Step 2: Interpret performance meaning

   No errors means system handled load well. Response time of 2.5 seconds is moderate speed, not very fast.

3. Final Answer:

   The system handles 100 users with no errors but response time is moderate -> Option A

4. Quick Check:

   No errors + moderate response = system handles load [OK]

Hint: Zero errors + response time shows load handling quality [OK]

Common Mistakes:

• Assuming 2.5 seconds is very fast
• Ignoring error rate meaning
• Confusing number of users with errors

4. A load test script is supposed to simulate 50 users but only 10 users are simulated. Which is the most likely cause?

medium

A. The load testing tool is configured to limit users to 10

B. The system under test crashed before test started

C. The script has a syntax error causing early termination

D. The network connection is too fast

Solution

1. Step 1: Understand the problem context

   The script aims for 50 users but only 10 appear. This suggests a configuration or environment issue.

2. Step 2: Evaluate options for cause

   A syntax error would likely stop the script entirely, not partially simulate users. System crash would stop all users. Network speed does not limit user count. Configuration limiting users to 10 fits best.

3. Final Answer:

   The load testing tool is configured to limit users to 10 -> Option A

4. Quick Check:

   User count limited by tool config = cause [OK]

Hint: Check tool user limit settings if fewer users simulated [OK]

Common Mistakes:

• Blaming syntax errors without checking config
• Assuming system crash without error logs
• Confusing network speed with user count

5. You want to test a web app's performance under increasing load. Which approach best fits load testing to find the maximum user capacity before response time exceeds 3 seconds?

hard

A. Only test the app's UI responsiveness manually

B. Gradually increase simulated users while measuring response time until it exceeds 3 seconds

C. Test with 10 users repeatedly without increasing load

D. Run a single test with 1000 users and check errors only

Solution

1. Step 1: Understand goal to find max capacity before response time limit

   This requires increasing load step-by-step and measuring response time.

2. Step 2: Evaluate options for best method

   Gradually increase simulated users while measuring response time until it exceeds 3 seconds describes gradual increase and measurement, which fits load testing best. Other options either test fixed load, ignore response time, or test UI manually, which do not meet goal.

3. Final Answer:

   Gradually increase simulated users while measuring response time until it exceeds 3 seconds -> Option B

4. Quick Check:

   Increase load + measure response time = find max capacity [OK]

Hint: Increase users stepwise, watch response time limit [OK]

Common Mistakes:

• Testing only fixed large user count
• Ignoring response time in load tests
• Relying on manual UI checks for load testing