Nodejs/express, shutdown gracefully

Question

I have an nodejs server running express to server out http calls. Is there a recommended approach to shutting down the server gracefully if something bad happens? Should I leave the server running somehow?

I.E. on an uncaught exception the server just stops, I think this will kill over connected clients and not hand them back a response.

Should I:

1. Wait for all http connections to complete before I allow the server to die (and then restart it).
2. Or should I try and stop the server from ever dieing?

is this proper?

process.on('exit', function () {
  console.log('About to exit, waiting for remaining connections to complete');
  app.close();
});

In this case an error might have been thrown leaving the server in an undefined state and the server will continue to finish up remaining connections.

Is there any good way to handle errors keep running or should I let the server die and restart?

Answer 1

NodeJS will shutdown when it's not expecting anything to happen; While the http server is waiting on connections node stays running.

server.close([callback])

Stops the server from accepting new connections and keeps existing connections. This function is asynchronous, the server is finally closed when all connections are ended and the server emits a close event. Optionally, you can pass a callback to listen for the close event.

After you do this the server will continue running until the last connection has finished and then shutdown gracefully.

If you don't want to wait for connections to terminate you can use socket.end() or socket.destroy() on your remaining connections.

See http://nodejs.org/api/net.html

---

process.on('exit', function () {
    console.log('About to exit, waiting for remaining connections to complete');
    app.close();
});

This function should run when node exists and not actually tell node to exit. Here is one way you can end your process but it wouldn't end gracefully:

process.exit([code])

Ends the process with the specified code. If omitted, exit uses the 'success' code 0.

To exit with a 'failure' code:

process.exit(1); The shell that executed node should see the exit code as 1.

See http://nodejs.org/api/process.html

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I hope this helps!