Stress testing concepts in Testing Fundamentals - Test Execution Trace

Test Overview

This test simulates a stress test on a web application by sending a high number of requests to check if the system can handle extreme load without crashing. It verifies that the application remains responsive and does not return error status codes under stress.

Test Code - PyTest

Testing Fundamentals

import requests
import threading
import time

# URL to stress test
url = "https://example.com/api/data"

# Number of concurrent requests
num_requests = 50

# Store results
responses = []

# Function to send a GET request
def send_request():
    try:
        response = requests.get(url, timeout=5)
        responses.append(response.status_code)
    except requests.exceptions.RequestException:
        responses.append('error')

# Start time
start_time = time.time()

# Create and start threads
threads = []
for _ in range(num_requests):
    thread = threading.Thread(target=send_request)
    threads.append(thread)
    thread.start()

# Wait for all threads to complete
for thread in threads:
    thread.join()

# End time
end_time = time.time()

duration = end_time - start_time

# Assertions
assert all(code == 200 for code in responses), f"Some requests failed: {responses}"
assert duration < 10, f"Stress test took too long: {duration} seconds"

Execution Trace - 6 Steps

Step	Action	System State	Assertion	Result
1	Test starts	Test environment ready, target URL set to https://example.com/api/data	-	PASS
2	Creates 50 threads to send GET requests concurrently	50 threads running, each sending a request to the server	-	PASS
3	Waits for all threads to complete	All requests completed, responses collected	-	PASS
4	Checks all response status codes are 200	Responses array contains status codes from all requests	assert all(code == 200 for code in responses)	PASS
5	Checks total test duration is less than 10 seconds	Duration calculated from start to end of requests	assert duration < 10	PASS
6	Test ends successfully	System handled stress load without errors or delays	-	PASS

Failure Scenario

Failing Condition: One or more requests return a status code other than 200 or the test duration exceeds 10 seconds

Execution Trace Quiz - 3 Questions

What does the test verify about the server responses?

A Responses are slower than 10 seconds

B Responses contain at least one error

C All responses have status code 200

D Responses have status code 404

Key Result

Stress testing uses many simultaneous requests to check system limits and ensures the system remains stable and responsive under heavy load.