total-cluster-without-downtimes.js

var http = require('http');
var path = require('path');
var cluster = require('cluster');
var os = require('os');
var fs = require('fs');
 
var debug = true;
 
if (!cluster.isMaster) {
    var F = require('total.js');
 
    // Set framework ID
    F.on('message', function(message) {
        if (message.type === 'id')
            framework.id = message.id;
 
        if (message.type == 'graceful_shutdown')
            F.stop();
    });
 
    F.http('release');
    return;
}
 
var shutdown_processing = false;
var pid = '';
var directory = process.cwd();
 
process.on('SIGTERM', end);
process.on('SIGINT', end);
process.on('exit', end);
 
function end() {
    fs.unlink(pid, noop);
    process.exit(0);
}
 
function noop() {}
 
process.on('SIGHUP', function() {
    if (shutdown_processing) {
        console.log('Already reloading...');
        return;
    }
 
    shutdown_processing = true;
 
    console.log('SIGHUP received, reloading workers...');
 
    var index = 0;
    var workers = Object.keys(cluster.workers);
 
    var workersKiller = function() {
        if (index == workers.length) {
            console.log('SIGHUP complete.');
            shutdown_processing = false;
            return;
        }
 
        // Process is already dead
        if (cluster.workers[workers[index]] === undefined) {
            index++;
            workersKiller();
            return;
        }
 
        console.log('killing worker %d', cluster.workers[workers[index]].process.pid);
 
        var shutdown_timer;
 
        // Graceful shutdown total.js
        cluster.workers[workers[index]].once('disconnect', function() {
            console.log('Worker %d disconnected', this.process.pid);
            clearTimeout(shutdown_timer);
        });
        cluster.workers[workers[index]].send({ type: 'graceful_shutdown' });
        cluster.workers[workers[index]].disconnect();
 
        shutdown_timer = setTimeout(function(timeout_worker) {
            console.log('could not close connections in time, forcefully shutting down (master)');
            timeout_worker.kill();
        }, 5000, cluster.workers[workers[index]]);
 
        // Spawn a new worker
        var fork = cluster.fork();
        fork.on('message', onMessage);
        fork.send({ type: 'id', id: i });
        fork.once('listening', function() {
            console.log('Worker replaced.');
            index++;
            workersKiller();
        });
    };
 
    workersKiller();
});
 
var numCPUs = os.cpus().length;
 
// Spawn total.js based on CPU count
for (var i = 0; i < numCPUs; i++) {
    var fork = cluster.fork();
    fork.on('message', onMessage);
    fork.send({ type: 'id', id: i });
}
 
function onMessage(message) {
    console.log('Message ->', message);
}
 
if (process.pid > 0) {
    console.log('MASTER PID: ' + process.pid);
    pid = path.join(directory, 'release.pid');
    fs.writeFileSync(pid, process.pid);
 
    pidInterval = setInterval(function() {
        fs.exists(pid, function(exist) {
            if (exist)
                return;
 
            process.exit(0);
        });
    }, 2000);
}