Question

I am developing a little project using Node.js. I am using mongoose for models, therefore i am using MongoDb. And i keep sessions in MongoStore. Also i want to use socket.io running several processes of Node. From socket.io docs:

    The MemoryStore only allows you deploy socket.io on a single process. 
If you want to scale to multiple process and / or multiple servers 
you can use our RedisStore which uses the Redis 
NoSQL database as man in the middle.

So i think i need Redis too. I am new in Node and i want to know – is it normal to use two databases to manage different parts of application. Or is there a way to work with socket.io when running several processes of Node and use only MongoDb

Answer 1

Just recently a solution that uses MongoStore with pub/sub functionality using mubsub (Pub/sub for Node.js and MongoDB) has appeared.

It can be attached to socket.io in almost the same way as you would with RedisStore:

io.configure(function() {
    io.set('store', new MongoStore({host: 'localhost', port: 27017, db:'session_db'}));
});

More information and source at: https://github.com/kof/socket.io-mongo