A socket.io server cluster using consistent hashing. A users socket connection request is mapped to a socket server that runs in the cluster, according to the query parameters of the socket connect request.

A use-case for this example is a game server, that separates users to socket servers according to the id of the game room instance. swim-hashring and firebird is used for creating a socket.io cluster and proxying requests. The server and proxy instances are containerized using docker, and hashring peers find eachother by querying docker containers that have the same image as them.

• Go to the root of the project and run docker-compose up this should start a single socket server and a proxy that points to this instance
• cd into client folder, and setup the client using npm install
• at the root of the project start a client by running node client/index.js http://localhost:8080 room_id where room_id can be any string you want.
• watch and see which server the client is connected to
• scale the socket server cluster by running docker-compose scale server=3 where 3 can be any number you want.
• the client may change server if the room_id you gave it to is assigned to another socket server in the cluster
• play around by starting new clients, and scaling the server count. you will observe the sockets that has the same room_id will always connect the same socket server.