Performance Testing Automation: Load, Stress, and Scalability

Performance Testing Fundamentals

Performance testing ensures your application can handle expected load and provides insights into scalability, bottlenecks, and user experience under various conditions.

Types of Performance Tests

• Load Testing: Verify system behavior under expected load
• Stress Testing: Determine system limits and breaking points
• Spike Testing: Test system response to sudden load increases
• Endurance Testing: Verify system stability over extended periods
• Scalability Testing: Measure system capacity to scale

Popular Performance Testing Tools

• JMeter: Apache's open-source load testing tool
• K6: Modern load testing tool with JavaScript
• Gatling: High-performance load testing framework
• Artillery: Cloud-native load testing platform
• LoadRunner: Enterprise-grade performance testing

K6 Performance Test Example

import http from 'k6/http';
import { check, sleep } from 'k6';

export const options = {
    stages: [
        { duration: '2m', target: 100 }, // Ramp up to 100 users
        { duration: '5m', target: 100 }, // Stay at 100 users
        { duration: '2m', target: 0 },   // Ramp down to 0 users
    ],
    thresholds: {
        http_req_duration: ['p(95)<500'], // 95% of requests must complete below 500ms
        http_req_failed: ['rate<0.1'],    // Error rate must be less than 10%
    },
};

export default function() {
    const response = http.get('https://api.example.com/users');
    
    check(response, {
        'status is 200': (r) => r.status === 200,
        'response time < 500ms': (r) => r.timings.duration < 500,
    });
    
    sleep(1);
}

JMeter Test Plan Example

<?xml version="1.0" encoding="UTF-8"?>
<jmeterTestPlan version="1.2" properties="5.0">
  <hashTree>
    <TestPlan guiclass="TestPlanGui" testclass="TestPlan" testname="API Load Test">
      <elementProp name="TestPlan.arguments" elementType="Arguments">
        <collectionProp name="Arguments.arguments"/>
      </elementProp>
      <boolProp name="TestPlan.functional_mode">false</boolProp>
      <boolProp name="TestPlan.tearDown_on_shutdown">true</boolProp>
      <boolProp name="TestPlan.serialize_threadgroups">false</boolProp>
    </TestPlan>
    <hashTree>
      <ThreadGroup guiclass="ThreadGroupGui" testclass="ThreadGroup" testname="User Load">
        <elementProp name="ThreadGroup.main_controller" elementType="LoopController">
          <boolProp name="LoopController.continue_forever">false</boolProp>
          <stringProp name="LoopController.loops">10</stringProp>
        </elementProp>
        <stringProp name="ThreadGroup.num_threads">100</stringProp>
        <stringProp name="ThreadGroup.ramp_time">60</stringProp>
      </ThreadGroup>
    </hashTree>
  </hashTree>
</jmeterTestPlan>

Performance Testing Best Practices

• Define clear performance requirements and SLAs
• Test in an environment similar to production
• Monitor system resources during testing
• Use realistic test data and scenarios
• Automate performance tests in CI/CD pipeline
• Set up performance monitoring and alerting

Performance Metrics to Monitor

• Response Time: Time to complete a request
• Throughput: Number of requests per second
• Error Rate: Percentage of failed requests
• Resource Utilization: CPU, memory, disk, network usage
• Concurrent Users: Number of simultaneous users

Recommended Books

• "Performance Testing with JMeter" by Bayo Erinle
• "The Art of Application Performance Testing" by Ian Molyneaux
• "Web Performance in Action" by Jeremy Wagner