LiveView performance problems - Morphdom taking up to 1500ms to patch updates

[Zurga]

@tmbb

Honestly, up until this performance problem (this is my first “big” phoenix form) I had never looked at the message size because it’s not too proeminent in the server logs and I don’t have a good intuition in converting nr of characters to kB (the logs show the received map but not the message size). I find it a little scary that I’m sending so much data upd and down for simple form validations. I think that for these amounts of data I’d have to think carefully about network bandwidth and prices… Of course, this is still all dwarfed by more data-intensive apps such as audio streaming or such, but here I am trying to get dynamic forms working and then comparing it to audio streaming (!), even if for short bursts when the user is actually editing the form.

Maybe it will help only with the message size, but I wrote a guide that explains how to switch to MessagePack encoding in the socket. I use it in production for a mobile first web app that sometimes has bad internet speed on the client side.

This will shave around 25% of the message size at the cost of message legibility in the developer console and a small decompression overhead.