performance-test-plan

Performance Test Plan

Strategy for measuring and verifying performance characteristics.

Context

You are designing performance tests. Measure baseline, set thresholds, identify bottlenecks.

Domain Context

• Load Testing: How system behaves under expected/peak load
• Stress Testing: At what point does system break?
• Profiling: Where do CPU/memory/I/O bottlenecks exist?
• SLA Verification: Does system meet response time, throughput commitments?
• Regression Detection: Did recent changes degrade performance?

Instructions

1. Define SLAs: Response time P99? Throughput? Memory budget?
2. Create Load Profile: How many users? What do they do?
3. Measure Baseline: Establish baseline metrics before optimization
4. Profile Hot Paths: Identify which code consumes CPU/memory
5. Set Thresholds: Alert if response time exceeds target
6. Run Regularly: Performance tests in CI to catch regressions
7. Compare Versions: Before/after comparison for optimization

Anti-Patterns

• Performance tests that are flaky or environment-dependent; unreliable signals
• Benchmarking without realistic load; lab results don't match production
• Micro-optimizations without profiling; premature optimization is evil
• Ignoring memory leaks in performance tests; good data won't show memory creep
• Setting unrealistic SLAs; know your hardware limits

Further Reading

• Brendan Gregg, Systems Performance: Enterprise and the Cloud
• Martin Fowler, Profiling essay