rust-production-reliability

A circuit breaker prevents cascading failures by monitoring call success rates and stopping requests when a threshold is exceeded. Implement one using Tokio for async execution, track failures atomically, and manage state transitions (Closed → Open → HalfOpen) to resume traffic after recovery.

Exponential backoff with jitter spreads retries over increasing intervals, preventing thundering herd problems. Combine this with Tower middleware to wrap service calls, apply configurable backoff curves, and set maximum retry limits for timeout-safe recovery.

Graceful shutdown coordinates clean termination by draining in-flight requests, closing connections, and flushing state. Use Tokio's cancellation signals, spawn shutdown managers that wait for task completion, and timeout remaining work to ensure predictable exit.

Yes, Tower 0.5.2 supports rate limiting and load shedding through middleware layers. Configure token buckets or sliding windows, reject excess requests early to protect downstream services, and shed load under peak traffic to maintain stability.

Timeouts fail fast on single slow requests; circuit breakers fail fast across many requests when a service is down. Use timeouts for individual calls and circuit breakers to prevent repeated attempts to unhealthy services, reducing waste and latency.

Health checks and observability enable monitoring service state and detecting failures early. Implement endpoints that report component health, emit metrics on failures and recovery, and log circuit breaker state changes for debugging and alerting.