JMeter Load Testing

1.   / 
2. Features   / 
3. Load Testing

---

Prerequisites

1. Install JMeter: Ensure JMeter is installed and the bin directory is accessible in your system PATH.
2. Required Plugin: Install the following JMeter plugin locally:
   • WebSocket Sampler
3. SAMA server is running: Put your server address in ws create conenction -> Server name or IP & Port.
4. Java Version: To run the tests, ensure that you are using Java version 20 or lower.
   • All tests were performed using Java 17.

Useful installation link for Mac users: How to Install Apache JMeter on macOS

Test Structure

The test plan is stored in a .jmx file, which defines the load test scenario.

• File: load_test.jmx

Key Test Case Details:

1. Each thread creates one user.
2. The user whose sequence number is a multiple of 4 creates a group chat with the previous three users.
3. Each user continuously sends messages to the chat with a delay of 5 seconds.

Load Configuration:

• Number of Threads: This is the total number of simulated users.
  • Each thread represents one user.
• Ramp-up Time: The total time for starting all threads.
  • To adjust the user creation frequency, use the formula: (Ramp-up Time) ÷ (Number of Threads) = Delay between user creation.
• Group Size: In the Test Plan, the GROUP_SIZE variable determines the number of users in a single chat group.
  • Number of chats = Math.floor(Number of Users / GROUP_SIZE)

Running the Tests

Run the Test via Console:

1. Prepare the Result Directory:

   • Create a folder named result in your desired output location.
   • Clear this folder before each test run.

2. Run the command to start: Execute the following command from the JMeter bin directory with administrator privileges:

   jmeter.bat -n -t "path_to_load_test.jmx" -l "path_to_result.jtl" -e -o "desired_output_location"

   • -t: Path to the .jmx test plan file.
   • -l: Path to save the result log file. (Not mandatory to review.)
   • -o: Path to save the HTML report. Note: The report will not generate if you stop the test using Ctrl + C.

In addition, you can always run tests inside the JMeter application.

Test Termination Conditions

The test will terminate if the CPU load exceeds 70% for the last 15 minutes. You can also modify these values according to your needs:

• CPU Load Threshold: Test Plan -> CPU_THRESHOLD = your value (70 by default)
• Time Period for CPU Load: Test Plan -> TIMEOUT_MINUTES = your value in minutes (15 by default)

Notes

• Use larger user numbers cautiously, keeping an eye on CPU and memory usage.
• Increase ramp-up time if threads are starting too quickly.

Test Results on Different Machines

You can see in the file - RESULTS.md