Am I setting up domain correctly for nodejs? - node.js

Question

I want to prevent my NodeJS app from crashing and read that using domain is the way to do it. I'm still a little confused though but followed what I saw to get it set up. Is this set up correctly? Do I need to change anything? Thanks.
var express = require('express');
var http = require('http');
var path = require('path');
var d = require('domain').create();
var app = express();
app.configure(function() {
//set up express
app.set('port', process.env.PORT || 3000);
app.use(app.router);
app.use(function(req,res){
res.redirect('/error');
});
});
//launch
d.on('error', function(er) {
console.log('Error!', er.message);
});
d.run(function() {
http.createServer(app).listen(app.get('port'), function(){
console.log('Express server listening on port ' + app.get('port'));
});
});
When I create in error in one of my route files it seems to work correctly, but the error isn't logging. Should I have it log to a file or something so I can check for errors later on?

Answer 1

Well, what you're doing is a bad practice according to the NodeJS documentation, since you can start a memory leak every time the error occurs. There's an example on the domain api docs page of the right way to do it. I'm not sure why console.log isn't working, however -- a log file is probably a good idea. Also be aware that the api for domain is still unstable and may change.
In short you should handle your errors gracefully and start a new worker process when an unexpected an error occurs (using the cluster module to start and stop workers that run into problems).
From the docs, this is what you're not supposed to do, which looks awfully close to what you're doing:
// XXX WARNING! BAD IDEA!
var d = require('domain').create();
d.on('error', function(er) {
// The error won't crash the process, but what it does is worse!
// Though we've prevented abrupt process restarting, we are leaking
// resources like crazy if this ever happens.
// This is no better than process.on('uncaughtException')!
console.log('error, but oh well', er.message);
});
d.run(function() {
require('http').createServer(function(req, res) {
handleRequest(req, res);
}).listen(PORT);
});