circuit-breaker

Circuit Breaker for Agents

Agent'lar da servisler gibi basarisiz olabilir. Ayni hatayi tekrar tekrar denemek token israf eder ve sorunu cozmez. Circuit breaker bunu onler.

3 Durum

CLOSED (Normal)
  Agent calisir, hatalar sayilir.
  Hata esigi asilirsa → OPEN'a gec.

OPEN (Devre Kesik)
  Agent CALISTIRILMAZ.
  Cooldown suresi boyunca bekle.
  Cooldown bitince → HALF-OPEN'a gec.

HALF-OPEN (Test)
  Tek bir istek gonder.
  Basarili → CLOSED'a don.
  Basarisiz → OPEN'a geri don (cooldown uzat).

     basarili          hata esigi
  ┌──────────┐      ┌───────────┐
  │          │      │           │
  ▼          │      ▼           │
CLOSED ──────┼── OPEN ────── HALF-OPEN
  ▲          │      │           │
  │          │      │           │
  └──────────┘      └───────────┘
     normal          cooldown bitti

Konfigrasyon

interface CircuitBreakerConfig {
  failureThreshold: number    // Kac hata sonrasi OPEN (default: 3)
  cooldownMs: number          // OPEN'da bekleme suresi (default: 60000 = 1 dk)
  halfOpenMaxAttempts: number // HALF-OPEN'da max deneme (default: 1)
  resetAfterMs: number        // Hata sayacini sifirla (default: 300000 = 5 dk)
  onOpen?: () => void         // OPEN'a gecince cagrilir
  onClose?: () => void        // CLOSED'a donunce cagrilir
}

const DEFAULT_CONFIG: CircuitBreakerConfig = {
  failureThreshold: 3,
  cooldownMs: 60000,
  halfOpenMaxAttempts: 1,
  resetAfterMs: 300000,
}

Uygulama

Agent Seviyesinde

class AgentCircuitBreaker {
  private state: 'CLOSED' | 'OPEN' | 'HALF-OPEN' = 'CLOSED'
  private failures = 0
  private lastFailureTime = 0
  private config: CircuitBreakerConfig

  constructor(private agentName: string, config?: Partial<CircuitBreakerConfig>) {
    this.config = { ...DEFAULT_CONFIG, ...config }
  }

  canExecute(): boolean {
    if (this.state === 'CLOSED') return true

    if (this.state === 'OPEN') {
      const elapsed = Date.now() - this.lastFailureTime
      if (elapsed >= this.config.cooldownMs) {
        this.state = 'HALF-OPEN'
        return true
      }
      return false
    }

    // HALF-OPEN: tek denemeye izin ver
    return true
  }

  recordSuccess(): void {
    this.failures = 0
    if (this.state === 'HALF-OPEN') {
      this.state = 'CLOSED'
      this.config.onClose?.()
    }
  }

  recordFailure(): void {
    this.failures++
    this.lastFailureTime = Date.now()

    if (this.state === 'HALF-OPEN') {
      this.state = 'OPEN'
      return
    }

    if (this.failures >= this.config.failureThreshold) {
      this.state = 'OPEN'
      this.config.onOpen?.()
    }
  }

  getStatus(): { state: string; failures: number; agent: string } {
    return { state: this.state, failures: this.failures, agent: this.agentName }
  }
}