Clustastic

Clustastic is a simple wrapper module for basic nodejs cluster application. This module enables you to run your "main" function code within a cluster of workers.

Installation

$ npm i clustastic --save

Usage

Just require the module, and pass your main function as the argument to the module function.

var clustastic = require('clustastic');

clustastic(main);

function main() {
	// Put your app initialization code here
}

Express application example:

var clustastic = require('clustastic');

clustastic(main);

function main() {
    var express = require('express');
    var app = express();

    app.get('/', function (req, res) {
        res.send('Response from worker ' + clustastic.workerId());
    });

    app.listen(3000);
}

Options

The module function second argument is an options object. If the options object is not provided, or a specific option is not provided, the module will fall back to a default value.

Number of workers

By default, clustastic will spawn workers as the number of CPU cores available on the machine. If you wish to override this, pass a workers property with the number of workers you wish to spawn. Any number between 1 and the number of CPU cores is accepted.

If you will provide an invalid value, an Error will be thrown with the message 'Invalid workers amount'.

Logging function

By default, clustastic will use console.log for logging. You may pass your own function to override this, by setting the logging property in the options object.

Any value that is not a function, will disable the logging.

Getting worker ID

You can get the ID of the worker within your code using the workerId function available on the clustastic module function.

var clustastic = require('clustastic');

clustastic(function() {
	console.log('Response from worker ' + clustastic.workerId());
});

Output with 4 cores CPU:

Response from worker 1
Worker 1 running
Response from worker 2
Worker 2 running
Response from worker 3
Worker 3 running
Response from worker 4
Worker 4 running