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Node.js Cluster Process Module

❮ Built-in Modules


Run the code three times, the first time is as a master, then as workers:
var cluster = require('cluster');

if (cluster.isWorker) {
  console.log('I am a worker');
} else {
  console.log('I am a master');
Run example »

Definition and Usage

The cluster module provides a way of creating child processes that runs simultaneously and share the same server port.

Node.js runs single threaded programming, which is very memory efficient, but to take advantage of computers multi-core systems, the Cluster module allows you to easily create child processes that each runs on their own single thread, to handle the load.


The syntax for including the cluster module in your application:

var cluster = require('cluster');

Cluster Properties and Methods

Method Description
disconnect() Disconnects all workers
exitedAfterDisconnect Returns true if a worker was exited after disconnect, or the kill method
fork() Creates a new worker, from a master
id A unique id for a worker
isConnected Returns true if the worker is connected to its master, otherwise false
isDead Returns true if the worker's process is dead, otherwise false
isMaster Returns true if the current process is master, otherwise false
isWorker Returns true if the current process is worker, otherwise false
kill() Kills the current worker
process Returns the global Child Process
schedulingPolicy Sets or gets the schedulingPolicy
send() sends a message to a master or a worker
settings Returns an object containing the cluster's settings
setupMaster() Changes the settings of a cluster
worker Returns the current worker object
workers Returns all workers of a master

❮ Built-in Modules