B · ExecuteIntermediate35 min read
6. Reading graphs honestly
Performance Testing Basics · 36 pages source format
Correlate latency, errors, and system metrics. Averages hide pain. Coordinate drops. Watch for coordinated omission and client-side bottlenecks.
What you'll learn
- Percentile graphs
- Error correlation
- Bottleneck hypotheses
Read a run
When p95 climbs, do errors climb? Is CPU maxed? DB locks?
Do this now
Annotate one test run: hypothesis for the bottleneck in 3 bullets.
Pro tip. If the load generator is saturated, you’re measuring your laptop.
Clear?