cluster_perf.js

var cluster = require('cluster');
var numCPUs = parseInt(process.argv[2]) || 1;

var ready_workers = [];
if (cluster.isMaster) {
    for (var i = 0; i < numCPUs; i++) {
        cluster.fork();
    }

    cluster.on('online', function (worker) {
        ready_workers.push(worker);
        if (ready_workers.length === numCPUs) send_msg();
    });

    var scount = 0;
    var time = process.hrtime();
    var i = 0;

    function send_msg () {
        // send 5000 then give the event loop a look-in.
        for (var n=0; n < 5000; n++) {
            var worker = ready_workers[i++];
            worker.send('msg');
            scount++;
            if (i === numCPUs) i = 0;
        }
        process.nextTick(send_msg);
    }

    setInterval(function () {
        var diff = process.hrtime(time);
        time = process.hrtime();
        var secs = (diff[0] * 1e9 + diff[1]) / 1e9;
        process.stdout.write("Rate: " + parseInt(scount/secs) + "       \r");
        scount = 0;
    }, 1000);
}