ubuntu jmeter性能测试

Installing Java Environment
JMeter is a Java-based tool, so a compatible JDK (Java Development Kit) is required. For Ubuntu, you can install OpenJDK using the following commands:

sudo apt update
sudo apt install openjdk-11-jdk  # Recommended version (JMeter 5.x+ supports Java 8+)

Verify the installation with:

java -version

This should display the installed Java version (e.g., “openjdk version 11.0.xx”).

Installing Apache JMeter

1. Download JMeter: Use wget to fetch the latest stable version from the official Apache website:

   wget https://downloads.apache.org/jmeter/binaries/apache-jmeter-5.6.3.tgz  # Replace with the latest version
   

2. Extract the Archive: Unzip the downloaded file to a directory (e.g., /opt for system-wide access):

   sudo tar -xzf apache-jmeter-5.6.3.tgz -C /opt
   

3. Configure Environment Variables: Edit the system profile file (/etc/profile) to add JMeter to your PATH:

   sudo vim /etc/profile
   

   Add these lines at the end (replace /opt/apache-jmeter-5.6.3 with your actual path):

   export JMETER_HOME=/opt/apache-jmeter-5.6.3
   export PATH=$JMETER_HOME/bin:$PATH
   

   Save the file and apply changes:

   source /etc/profile
   

4. Verify Installation: Run jmeter -v to confirm JMeter is accessible. You should see version details (e.g., “Apache JMeter 5.6.3”).

Creating a Basic Test Plan
JMeter uses “test plans” (.jmx files) to define performance tests. Here’s how to create one via the GUI (for simplicity) and run it in non-GUI mode:

1. Open JMeter GUI: Run jmeter from the terminal to launch the graphical interface.
2. Add a Thread Group: Right-click “Test Plan” → “Add” → “Threads (Users)” → “Thread Group”. Configure:
   • Number of Threads (users): Number of concurrent users (e.g., 50).
   • Ramp-up Period (seconds): Time to start all threads (e.g., 10 seconds).
   • Loop Count: Number of iterations (e.g., 10).
3. Add an HTTP Request: Right-click the Thread Group → “Add” → “Sampler” → “HTTP Request”. Fill in:
   • Server Name or IP: Your target server (e.g., example.com).
   • Path: The endpoint to test (e.g., /api/v1/users).
4. Add Listeners: Listeners collect and display results. Right-click the Thread Group → “Add” → “Listener” → “Aggregate Report” (for summary metrics) and “View Results Tree” (for detailed request/response data, disable in production).
5. Save the Test Plan: Click “File” → “Save As” and name it (e.g., my_test_plan.jmx).

Running Performance Tests (Non-GUI Mode)
Non-GUI mode is essential for high-concurrency tests—it reduces resource usage on the client machine. Use this command:

jmeter -n -t /path/to/my_test_plan.jmx -l /path/to/results.jtl -e -o /path/to/report

• -n: Non-GUI mode.
• -t: Path to the test plan (.jmx) file.
• -l: Path to save results (.jtl file, contains raw data).
• -e: Generate HTML report after the test.
• -o: Directory to store the HTML report (must be empty).

Example:

jmeter -n -t ~/jmeter/my_test_plan.jmx -l ~/jmeter/results.jtl -e -o ~/jmeter/report

After the test completes, open the HTML report in ~/jmeter/report/index.html to view metrics like response time, throughput, and error rate.

Monitoring System Resources During Testing
To analyze performance bottlenecks, monitor server resources (CPU, memory, disk I/O) during the test. Use these tools:

1. Top: Real-time view of CPU and memory usage:

   top
   

   Press Shift + P to sort by CPU usage, Shift + M for memory.
2. Vmstat: System-wide performance stats (run every second for 60 seconds):

   vmstat 1 60 > vmstat.log
   

   The log includes CPU idle time, memory usage, and disk I/O.
3. Nmon: Detailed resource monitoring (install via sudo apt install nmon):

   nmon -f -s 1 -c 60
   

   This generates a .nmon file (use nmon_analyzer to convert it into charts).

Best Practices for Effective Testing

• Use Non-GUI Mode Always: GUI mode consumes significant CPU/memory (~10-25% of system resources). Reserve it for test creation/debugging only.
• Limit Listeners in Production Tests: Listeners like “View Results Tree” store detailed request/response data, which increases memory usage. Disable them during high-concurrency tests and use them only to analyze specific requests.
• Optimize JMeter Memory: Edit the jmeter script (in the bin directory) to increase heap size. For example, set:

  HEAP="-Xms1g -Xmx4g -XX:MaxMetaspaceSize=512m"
  

  This allocates 1GB initial heap, 4GB maximum heap, and 512MB for metadata.
• Distribute Load for High Concurrency: For tests exceeding 500 concurrent users, use JMeter’s distributed testing feature (set up multiple “slave” machines to run tests in parallel).

Troubleshooting Common Issues

• Java Not Found: If you see java: command not found, ensure Java is installed and JAVA_HOME is correctly set in /etc/profile.
• Port Conflicts: JMeter uses port 1099 by default for distributed testing. If another process uses it, change the port in jmeter.properties (look for server.rmi.localport).
• Plugin Errors: If you encounter NoClassDefFoundError (e.g., for WebSocket plugins), install the required dependencies. For WebSocket tests, download jetty-http, jetty-util, and websocket-client JARs and place them in the lib/ext directory.