nodeJS server slow and jerky performance?

Question

nodeJS server slow and jerky performance?

Using nodeJS and socket.io as an excercise I built a prototype of a mouse cursor, controlled by an iphone, that moves on the browser viewport. that's it. it works, but the performance is really bad. the cursor is jerky, chopped...it doesnt move smoothly...as I see in my terminal the emission and sometimes it gets stuck...

I was thinking of using something like code below, but is still way from being optimal..

setInterval(function() {
   socket.emit('sendposition', x, y);
}, 25);

I wonder if thatere is any best practice to improve the performance.. How can you build an online multiplayer game, if the performance is so poor?

thanks!

javascript
node.js
heroku

Answer 1

There is probably jitter in the network traffic, which is normal, particularly for TCP traffic where the network guarantees in-order delivery, so that when one packet is late, all the others behind it have to wait.

I recommend you try it with UDP, with each datagram containing a delta in the X,Y position. That way, if a few packets are out of order, the mouse still gets to the same destination, and if a few packets are dropped then the other packets still come through and nudge the cursor along anyway.

Answer 2

I tried using socket.send, instead of socket.emit, and it sounds...better..not perfect but way better...