This article demonstrates how to model token bucket algorithms for preventing retry storms in distributed systems using PlusCal and TLA+. It highlights a subtle concurrency trap that can occur when implementing token buckets in client drivers and shows how formal modeling can identify these issues. The token bucket mechanism helps prevent self-inflicted denial of service by gracefully limiting retries when downstream services fail.
Background
Token buckets are a common rate-limiting technique in distributed systems that help prevent retry storms, where failed requests trigger cascading retries that overwhelm services. PlusCal and TLA+ are formal specification languages used for modeling and verifying concurrent systems.
- Source
- Lobsters
- Published
- Mar 17, 2026 at 01:47 AM
- Score
- 6.0 / 10