Isolating app crashes for users in node

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I have built a web application with node + express and I'm currently testing it.

I realised that when more than one client is connected, a application crash for one client affects all the other clients and resets their sessions when the app restarts.

I want a way to prevent this from happening, so that one user experiencing a crash doesn't affect other connected users.

I read sometime ago about the possibility of using clusters for this (clusters aren't stable yet, at this time), but it isn't working as expected.

This is what I have currently:

var
    cluster = require('cluster'),
    numCPUs = require('os').cpus().length;

var
    express      = require('express'),
    fibrous      = require('fibrous'),
    engine       = require( 'ejs-locals' ),
    http         = require('http'),
    path         = require('path'),
    app          = express(),
    fs           = require('fs');


// App Config
app.configure('development', function(){
  app.use(express.errorHandler({ dumpExceptions: true, showStack: true }));
});

app.configure( 'production', function(){
  app.use(express.errorHandler());
});

app.configure(function(){
  app.set('port', process.env.PORT || 5000);
  app.engine( 'ejs', engine );
  app.set('views', __dirname + '/views');
  app.set('view engine', 'ejs');
  app.use(express.favicon());
  app.use(express.logger('dev'));
  app.use(express.bodyParser({ keepExtensions: true }));
  app.use(fibrous.middleware);
  app.use(express.methodOverride());
  app.use(express.cookieParser());
  app.use(express.session({ secret: "sailup" }));
  app.use(app.router);
  app.use(express.static(path.join(__dirname, 'public')));
  // Handle 404
  app.use(function(req, res) {
    process.exit( 1 );
    res.status(404);
    res.render('404', {
      title: 'Page not found',
      pagestyles: [{
        src: '/assets/css/404.css'
      }],
      pagescripts: [{
        src: '/assets/js/404.js'
      }]
    });
  });

  // Handle 500
  app.use(function(error, req, res, next) {
    console.log(error.stack);

    res.status(500);
    res.render('500', {
      title: 'Something went wrong',
      message: errorMessage,
      pagestyles: [{
        src: '/assets/css/500.css'
      }],
      pagescripts: [{
        src: '/assets/js/500.js'
      }]
    });
  });
}); // Configs End


// Locate and Load Routes
var routesDir = 'routes',
    routeFiles = fs.readdirSync(routesDir);

routeFiles.forEach(function(file) {
  var filePath = path.resolve('./', routesDir, file),
      route = require(filePath);
  route.init(app);
}); // Done Loading Routes

if (cluster.isMaster) {
  // Fork workers.
  for (var i = 0; i < numCPUs; i++) {
    cluster.fork();
  }

  cluster.on('exit', function(worker, code, signal) {
    console.log('worker ' + worker.process.pid + ' died');
  });
} else {
  // Workers can share any TCP connection
  // In this case its a HTTP server
  // Start The Server Now :)
  http.createServer(app).listen(app.get('port'), function(){
     console.log('running');
  });
}

But it looks like everything runs more than once. For instance, the log statement prints about 4 times and even though crashes are not affected somehow. But most importantly, it looks like my sessions are messed up. Any new page I visit acts as though no session exists. I think the sessions are being lost somehow.

If you know a better way of achieving this, please do help me out. If you can help make this work too, I would be glad to hear from you. Thanks :)

asked 1 min ago

elimence

322