node-heartbeat

Application heartbeat that emits process / system stats periodically

Usage

const heartbeat = require('@vanioinformatika/heartbeat')

const processTitle = 'my_process'
const id = uuid.v4()
const appState = () => {
  return myAppStateHandler.queryAppState() // query your application state from whatever source 
}
const callback = (beatObject) => {
  mySpecificLogger.info('heartbeat', beatObject)
}
const interval = 60000 // 1 minute

heartbeat.start() // start beating when the application starts

...

heartbeat.stop() // stop beating when the application stops

API

Factory

heartbeat(title: string, id: string, appState: Function, callback: Function, [interval: number = 60000]): Heartbeat

Parameters:

• title: String, process title
• id: String, unique id of the process (in case of dockerized application it would be the container ID as the process ID is always 1)
• appState: Function, should return any application specific state descriptor object. Its return value will appear in the heartbeat object with state key.
• callback: Function, this will be called periodically on every heartbeat, it has one parameter, the beatObject thet contains the process info
• interval: Number, the heartbeat interval in milliseconds (default: 60000 i.e. 1 min)

start

start(): void

Starts the heartbeat scheduler.

stop

stop(): void

Starts the heartbeat scheduler.

beat

beat(): void

The actual heartbeat emitter function that creates the beat object and calls the callback. It can be useful if an extra heartbeat is required.