When should I use createCircuitBreaker instead of retry?

[clyxudev]

I understand retry handles temporary failures, but when should I use createCircuitBreaker, and what do open or half-open states mean in this package?

[shnwazdeveloper]

Use retry for one operation that may recover after a few attempts. Use createCircuitBreaker when a dependency is failing repeatedly and you want to stop sending traffic for a recovery window.

In this package:

• closed: calls go through normally.
• open: calls fail fast with CircuitBreakerOpenError until recoveryTime passes.
• half-open: the breaker allows test calls; enough successes closes it again.

import { createCircuitBreaker } from "@shnwazdeveloper/shnwazdev";

const breaker = createCircuitBreaker(
  () => fetch("https://api.example.com/health"),
  {
    failureThreshold: 3,
    recoveryTime: 30_000,
    successThreshold: 1,
    onStateChange(next, previous) {
      console.log({ previous, next });
    }
  }
);

const response = await breaker.execute();

A good rule: use retry for temporary noise; use a circuit breaker to protect your app when the same downstream service is unhealthy.