Core Concepts
Load Testing Types
- Load Testing - Expected load performance
- Stress Testing - Beyond capacity limits
- Spike Testing - Sudden load increases
- Soak Testing - Extended duration performance
- Scalability Testing - System growth capacity
- Volume Testing - Large data handling
Key Metrics
- Response Time - Request completion time
- Throughput - Requests per second (RPS)
- Error Rate - Percentage of failed requests
- Latency - Time to first byte (TTFB)
- Concurrent Users - Simultaneous active users
- Resource Utilization - CPU, memory, network
Tools & Frameworks
- Apache JMeter - Java-based load testing
- k6 - Modern JavaScript load testing
- Gatling - Scala-based performance testing
- Locust - Python-based load testing
- Artillery - Node.js load testing
- Vegeta - Go HTTP load testing
Best Practices
Test Design
- Start with baseline performance
- Define clear performance goals
- Use realistic load patterns
- Include think time between requests
- Test with production-like data
- Monitor system resources
Load Patterns
- Ramp-up gradually
- Test at sustained load
- Include spike scenarios
- Test soak/endurance
- Validate under stress
- Test auto-scaling
Metrics & Analysis
- Define SLAs upfront
- Monitor response times (p50, p95, p99)
- Track error rates
- Measure throughput
- Monitor resource utilization
- Analyze bottlenecks
Environment
- Use dedicated test environment
- Match production configuration
- Isolate test traffic
- Monitor database performance
- Test with CDN if applicable
- Include third-party dependencies
Anti-Patterns
Common Mistakes
- Testing from single location only
- Not ramping up load gradually
- Ignoring think time
- Testing without monitoring
- No baseline for comparison
- Testing in production
Test Design Issues
- Unrealistic load patterns
- Missing data variation
- No error handling
- Hard-coded test data
- Ignoring cache effects
- Not testing edge cases
Analysis Problems
- Focusing only on averages
- Ignoring outliers
- Not correlating metrics
- Missing resource bottlenecks
- No root cause analysis
- Incomplete reporting
Reference Documentation
Detailed material lives alongside this skill and is read on demand:
- Implementation Examples — k6 Load Test Script, JMeter Test Plan (XML), Gatling Load Test (Scala), Python Locust Example
Resources
Official Documentation
- k6 Documentation - Modern load testing
- JMeter Manual - Complete guide
- Gatling Documentation - Performance testing
- Locust Documentation - Python load testing
Learning Resources
- Performance Testing Guidance - Best practices
- k6 YouTube - Video tutorials
- JMeter Academy - Training
- Awesome Load Testing - Curated resources
Tools & Platforms
- BlazeMeter - JMeter cloud platform
- k6 Cloud - k6 SaaS platform
- Grafana Cloud k6 - Monitoring integration
- Artillery Pro - Enterprise features
Community Resources
- k6 Community - Forums
- JMeter Forum - Mailing lists
- Load Testing Slack - k6 Slack channel
- Performance Testing Reddit - Discussions