There is already a Connect Middleware for Timeout support:
var timeout = express.timeout // express v3 and below
var timeout = require('connect-timeout'); //express v4
app.use(timeout(120000));
app.use(haltOnTimedout);
function haltOnTimedout(req, res, next){
if (!req.timedout) next();
}
If you plan on using the Timeout middleware as a top-level middleware like above, the haltOnTimedOut middleware needs to be the last middleware defined in the stack and is used for catching the timeout event. Thanks @Aichholzer for the update.
Keep in mind that if you roll your own timeout middleware, 4xx status codes are for client errors and 5xx are for server errors. 408s are reserved for when:
The client did not produce a request within the time that the server was prepared to wait. The client MAY repeat the request without modifications at any later time.