CircuitBreaker middleware

The CircuitBreaker middleware wraps function calls with a circuit-breaker, providing fault tolerance for distributed systems. Each unique key (derived from the function's arguments) gets its own circuit instance. When the circuit is open, the wrapped function is not called and an error is thrown instead, preventing cascading failures.

Usage

import { withCircuitBreakerFactory } from "@daiso-tech/core/circuit-breaker/middlewares";
import { CircuitBreakerFactory } from "@daiso-tech/core/circuit-breaker";
import { MemoryCircuitBreakerStorageAdapter } from "@daiso-tech/core/circuit-breaker/memory-circuit-breaker-storage-adapter";
import { DatabaseCircuitBreakerAdapter } from "@daiso-tech/core/circuit-breaker/database-circuit-breaker-adapter";

const circuitBreakerFactory = new CircuitBreakerFactory({
    adapter: new DatabaseCircuitBreakerAdapter({
        adapter: new MemoryCircuitBreakerStorageAdapter(),
    }),
});
const withCircuitBreaker = withCircuitBreakerFactory(circuitBreakerFactory);

const callExternalApi = async (endpoint: string): Promise<unknown> => {
    const response = await fetch(`https://api.example.com/${endpoint}`);
    return response.json();
};

// Wrap with circuit-breaker
const protectedCall = use(
    callExternalApi,
    withCircuitBreaker({
        key: (endpoint) => `api:${endpoint}`,
    }),
);

await protectedCall("users"); // Succeeds or opens the circuit on repeated failures

info

Here is a complete list of settings for the withCircuitBreaker function.

Further information

For further information refer to @daiso-tech/core/circuit-breaker API docs.