Real-Time Phoenix

When to Write a New Socket

We’ve written two Sockets so far, UserSocket and AuthSocket, and we wrote Channels for each of them. This raises the question of when we should create a new Socket versus using the same topic and adding a new Channel. You’ll make this decision based primarily on the authentication needs of your application. There are also performance costs to adding new Sockets; let’s look at these costs first.

Each connected Socket adds one connection to the server, but each connected Channel adds zero new connections to the server. Channels do take up a slight amount of memory and CPU because there is a process associated with each, but you can consider Channels nearly free because processes are cheap in Elixir. Sockets are a bit ...