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ckt-breaker

ckt-breaker Build Status Coverage Status

Tiny circuit breaker implementation. Wrapped service must return Promise.

Requirements

  • node v6+
  • npm 3+ ## Install
$ npm install --save ckt-breaker

Usage

const cktBreaker = require('ckt-breaker');
// Function that hits some service  
const fn = () => Promise.reject('I got nothing');
 
const ckt = cktBreaker(fn, {
    retry: 10000, // time in ms after which to retry hitting fn 
    timeout: 1000, // time in ms to timeout if fn takes longer than that 
    maxError: 10, // Max no of errors 
    maxTime: 1000, // time in ms in which maxError occurs 
    fallback: () => Promise.reject(new Error('Service Currently unavailable')),
});
 
ckt.fire('hello world') // Safe doesn't overload the remote service 

API

cktBreaker(fn, {options})

fn

Type: function

A promise returning function

options

retry

Type: integer
Default: 10000

Time in ms after which to retry hitting fn

timeout

Type: integer
Default: 0

Time in ms to timeout fn if fn takes longer than that. By default this is disabled (0).

maxError

Type: integer
Default: 10

No of errors in maxTime time to occur before breaking the circuit

maxTime

Type: integer
Default: 1000

Time Frame to consider maxError no of error to break the circuit

fallback

Type: function
Default: () => Promise.reject(new Error('Service Currently unavailable')

Fallback function to call when circuit is broken

Methods

fire

const ckt = cktBreaker(fn); 
ckt.fire([1,2,3]) // Any args taken by fn;

Function that runs wrapped fn and passes over arguments given to it

Events

open

Fired when circuit is opened

closed

Fired when circuit is closed

License

MIT © Nikhil Srivastava