Circuit Breaker — Slow Call Rate

closed

closed open half-open

Requests flow through. Every call succeeds — but the breaker is timing how long each one takes.

Call latency · last 10 calls 0 / 0 slow · 0%

slow ≥ 500ms

← oldernewest →

slow-call rate trips at 50%

Auto traffic — simulate a real client

Downstream latency 200ms

Drag this above the slow line and the bars turn amber — the downstream isn't erroring, just lagging. Push slow calls past the rate threshold and it trips anyway.

Window size10

Slow if over500ms

Slow-rate trip50%

Open wait4s

Half-open trials3

total

slow calls

rejected

trips

Event log f = fast · s = slow · r = reset

Slow-call-rate circuit breaker showing how calls slower than a duration threshold trip the breaker once their share crosses a rate threshold.