Node.js Cluster Process Module
Example
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');
cluster.fork();
cluster.fork();
}
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.
Syntax
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 |
