Can you give an example how that would work with phoneix pubsub? I have searched the forum but couldn’t find one.
Ideally, I wish I could put phoenix pubsub in it’s own app apps/pubsub and point apps/web to it.
config :web, Test.Web.Endpoint,
url: [host: "localhost"],
secret_key_base: "...",
render_errors: [view: Test.Web.ErrorView, accepts: ~w(html json)],
pubsub: [app: :pubsub] # where :pubsub is an app in umbrella
The problem I’m having with pubsub being in apps/web is that I can’t be sure that Test.Web.Endpoint is loaded when I make a call to it like Test.Web.Endpoint.subscribe from some other app like apps/user.
And if I am to use Phoenix.PubSub.subscribe from inside apps/user, then that (I think) requires me to add phoenix_pubsub as a dependency to apps/user.
Now that I think about it, it might be better to leave phoenix pubsub to deal with websockets and the like, and either write a global distributed registry/pubsub myself or use something like swarn [0]. Not sure though.
I am also not sure how some things are implemented in phoenix pubsub (I’ve been planning to read it, but I’m afraid I don’t know elixir well enough to understand it fully), for example, does it batch messages when passing between nodes or not? Because it seems it can be somewhat of a bottleneck [1] if every message is sent with send.
[0] GitHub - bitwalker/swarm: Easy clustering, registration, and distribution of worker processes for Erlang/Elixir · GitHub
[1] http://www.ostinelli.net/boost-message-passing-between-erlang-nodes/
