Histograms and Coordinated Omission

Status Draft outlineSection Performance Engineering

Histograms approximate distributions through buckets. A load generator that waits for a delayed response before scheduling more work can omit the delay’s consequences.

Planned model

Compare closed-loop and open-loop load generation through an injected stall. Display intended arrivals, actual requests, omitted samples, and resulting histograms.

Questions

• What precision and range do histogram buckets provide?
• Why does a closed loop under-sample periods of poor service?
• What correction is possible, and what assumptions does it make?

Exercise

Design a latency test whose request schedule remains independent of the system’s response latency.