ugudango / yjs-scalable-ws-backend

About

Example of horizontally scalable websocket backend for y-js to be used with y-websocket provider with persitence to postgresql using knex.

Usage

1. npm ci
2. npm run build
3. cp .env.example .env.local
4. Fill in .env.local
5. npm run tables -> creates the tables for doc persistence in db
6. npm run dev -> starts the websocket-server
7. On the client-side, initialize a yjs doc and use the y-websocket provider to connect to the websocket-server

How it works

This repo is a slightly reworked websocket server found in the y-websocket repo(link).

The websocket-server that comes with y-websocket essentially maintains a copy of the y-js document(s) in memory and syncs it between different clients connected to the same doc.

The websocket-server in this repo isolates the updates that clients send to it, persists these updates to the database, and publishes these updates (using redis-pubsub) in a channel for the document. Also, when a doc is created for the first time in the websocket-server, the server reads all the updates stored in the database, and applies those updates to the document, effectively initializing it.

This makes the websocket-server provided in this repo persistent and horizontally-scalable on paper.

The code in this repo hasn't been tested in a production system yet, and from the looks of it, will be a long time before I would be able to run it on a production system, but theoretically, the code in this repo should be sufficient and can be tweaked to suit any project.