@psyqueue/plugin-circuit-breaker

Circuit breaker pattern for PsyQueue. Protect downstream services from cascading failures.

Installation

npm install @psyqueue/plugin-circuit-breaker

Usage

import { circuitBreaker } from '@psyqueue/plugin-circuit-breaker'

q.use(circuitBreaker({
  breakers: {
    'payment-api': {
      failureThreshold: 5,
      failureWindow: 30_000,
      resetTimeout: 60_000,
      halfOpenRequests: 3,
      onOpen: 'requeue',
    },
  },
}))

q.handle('payment.charge', async (ctx) => {
  return ctx.breaker('payment-api', async () => {
    return await chargePayment(ctx.job.payload)
  })
})

Configuration

| Option | Type | Default | Description | |--------|------|---------|-------------| | failureThreshold | number | required | Failures to trip the breaker | | failureWindow | number | required | Failure counting window (ms) | | resetTimeout | number | required | Time before OPEN to HALF_OPEN (ms) | | halfOpenRequests | number | required | Successes in HALF_OPEN to close | | onOpen | 'requeue' \| 'fail' | 'requeue' | Action when circuit is open |

Exports

• circuitBreaker(opts) -- Plugin factory
• Breaker -- Individual breaker class

Documentation

See Reliability Plugins for detailed usage.

License

MIT