Rate Limiter Simulator

1. Traffic Generate arrivals with RPS and burst shape.

2. Rate limit Each request must pass every sliding window rule.

3. Backend Accepted requests run, queue, or time out.

4. Read chart Arrivals always stay visible as the baseline.

Inputs

Traffic

Controls how many requests enter the system.

Duration seconds Step milliseconds Target RPS requests/sec Burst factor 0 to 1 Max concurrent in flight Queue capacity requests Max queue wait milliseconds

90 rps with 40% burst wave over 30s

Policy

Rate Limiter

Rules are evaluated in order. A request rejected by any rule becomes a 429.

Window algorithm How requests are counted inside each window

Rate limit rules Every request must pass all rules. Policy rejects are 429.

Backend

Service Latency

Models how long accepted requests occupy backend capacity.

Distribution Mean latency milliseconds Std deviation milliseconds

Normal / Gaussian

Control plane

Rate-Limiter Latency

Models time spent deciding allow or reject before backend admission.

Decision distribution Decision latency milliseconds Unused ignored for constant/exponential

Constant

Result

Analytics

Summary from the latest run.

Time series

Capacity, Admissions, and Rejections

429 means rate limited. 503 means backend queue full or timed out.

Distribution

Latency Distribution

Observed served-request latency, bucketed in milliseconds.