Bubble · Diagram Design

The biggest risk is not the slowest service

Nine services by p95 latency and error rate, bubble area proportional to requests per second, both axes from zero. Reports is the slowest thing on the board and barely matters; Payments runs near-peak traffic at the highest error rate, and that is where the incident will come from.

The biggest risk is not the slowest service Bubble chart of nine services by p95 latency and error rate on zero-based axes, bubble area proportional to requests per second; Payments carries near-peak traffic at the highest error rate. ERROR RATE, % P95 LATENCY, MS 1 2 3 4 0 0 100 200 300 400 500 PAYMENTS GATEWAY REPORTS LEGEND P95 VS ERROR RATE, BUBBLE AREA ∝ REQUESTS PER SECOND · BOTH AXES START AT ZERO · ILLUSTRATIVE FIGURES, NOT MEASURED SERVICES Payments · focal, highest error rate at near-peak traffic Service · faintest fill is the largest bubble

FOCAL · PAYMENTS

Payments burns the error budget fastest

2.8% of 760 requests per second — the highest error rate on the board applied to nearly the biggest volume. The accent marks the risk, not the worst number in any one column: Reports has worse latency and Gateway has more traffic, but neither multiplies out to as many failing requests.

Gateway shows where mass should sit

The largest bubble sits in the bottom-left corner — 900 requests per second at 85ms and half a percent of errors. Area is what keeps that reading honest: 900 is fifteen times Reports' 60, and the bubble carries fifteen times the ink. Radius-proportional sizing would square that into a 225-to-one blot.

Reports is slow and it does not matter

460ms p95 — the worst latency here — on 60 requests per second. The x-position raises the alarm and the tiny area answers it. Cropping the size encoding out of this chart turns Reports into the headline; that is the lie of every latency-only ranking.