Node.js Deploying Node.js applications in production Taking advantage of clusters
Example
A single instance of Node.js runs in a single thread. To take advantage of multi-core systems the user will sometimes want to launch a cluster of Node.js processes to handle the load.
var cluster = require('cluster');
var numCPUs = require('os').cpus().length;
if (cluster.isMaster) {
// In real life, you'd probably use more than just 2 workers,
// and perhaps not put the master and worker in the same file.
//
// You can also of course get a bit fancier about logging, and
// implement whatever custom logic you need to prevent DoS
// attacks and other bad behavior.
//
// See the options in the cluster documentation.
//
// The important thing is that the master does very little,
// increasing our resilience to unexpected errors.
console.log('your server is working on ' + numCPUs + ' cores');
for (var i = 0; i < numCPUs; i++) {
cluster.fork();
}
cluster.on('disconnect', function(worker) {
console.error('disconnect!');
//clearTimeout(timeout);
cluster.fork();
});
} else {
require('./app.js');
}
