SKILL.md
Circuit Breaker Pattern
Table of Contents
- [Overview](#overview)
- [When to Use](#when-to-use)
- [Quick Start](#quick-start)
- [Reference Guides](#reference-guides)
- [Best Practices](#best-practices)
Overview
Implement circuit breaker patterns to prevent cascading failures and provide graceful degradation when dependencies fail.
When to Use
- External API calls
- Microservices communication
- Database connections
- Third-party service integrations
- Preventing cascading failures
- Implementing fallback mechanisms
- Rate limiting protection
- Timeout handling
Quick Start
Minimal working example:
enum CircuitState {
CLOSED = "CLOSED",
OPEN = "OPEN",
HALF_OPEN = "HALF_OPEN",
}
interface CircuitBreakerConfig {
failureThreshold: number;
successThreshold: number;
timeout: number;
resetTimeout: number;
}
interface CircuitBreakerStats {
failures: number;
successes: number;
consecutiveFailures: number;
consecutiveSuccesses: number;
lastFailureTime?: number;
}
class CircuitBreaker {
private state: CircuitState = CircuitState.CLOSED;
private stats: CircuitBreakerStats = {
failures: 0,
// ... (see reference guides for full implementation)Reference Guides
Detailed implementations in the references/ directory:
| Guide | Contents |
|---|---|
| TypeScript Circuit Breaker | TypeScript Circuit Breaker |
| Circuit Breaker with Monitoring | Circuit Breaker with Monitoring |
| Opossum-Style Circuit Breaker (Node.js) | Opossum-Style Circuit Breaker (Node.js) |
| Python Circuit Breaker | Python Circuit Breaker |
| Resilience4j-Style (Java) | Resilience4j-Style (Java) |
Best Practices
✅ DO
- Use appropriate thresholds for your use case
- Implement fallback mechanisms
- Monitor circuit breaker states
- Set reasonable timeouts
- Use exponential backoff
- Log state transitions
- Alert on frequent trips
- Test circuit breaker behavior
- Use per-dependency breakers
- Implement health checks
❌ DON'T
- Use same breaker for all dependencies
- Set unrealistic thresholds
- Skip fallback implementation
- Ignore open circuit breakers
- Use overly aggressive reset timeouts
- Forget to monitor