nice! I just saw Registry.dispatch, is it this you were referring to?
I’m used to use Registry with :via. I didn’t see this function 
alvises
Fl4m3Ph03n1x
Good question. I actually don’t care about the response. I only care that I made the request. So I won’t be waiting for anything.
I am also using the Registry in a preliminary solution attempt, but thanks for pointing out!
Now this is interesting to me. I know Registry removes dead processes, which is great, but if that is all it does, then overtime time (as some processes eventually fail) I will end up with an empty Registry.
You mentioned int depends on which supervisor it is using. Great news for me. Can I tell this supervisor to create a new gun connection to replace the dead one? (By passing a function or something?)
I couldn’t find documentation about this.
This is interesting. Do you mean that the Registry process would actually be the bottleneck here? I have trouble understanding that, since the Registry uses the ETS, which goes back to the first approach I mentioned.
I will attempt to create a better post latter on, with all my questions and without the (horrible) analogy that is confusing everyone.
You can do it via dispatch, yes. But the docs go even further:
https://hexdocs.pm/elixir/master/Registry.html#module-using-as-a-pubsub
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peerreynders
Unlikely as the lookup would be pretty quick. But ETS has been optimized for shared access so any additional layer over top like a guardian process would tend to slow things down - whether that matters is a separate story.
You do likely care that a process received your request. Because a send (or cast) to a dead pid won’t result in an error.
Supervisors simply restart processes the same way they started them the last time - for something a bit smarter (and therefore more fragile) look into parent (Rationale).
If for whatever reason a fresh process cannot create it’s own connection it could always get another (named, specialized) process to create it.
Looked at The Hitchhiker’s Guide to the Unexpected yet?
Smart systems make stupid mistakes
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benwilson512
Author of Craft GraphQL APIs in Elixir with Absinthe
There is no single Registry process. Registry is very well optimized having been derived from Phoenix pubsub. It is not likely to be your bottleneck.
Sending a message doesn’t require that you get a response.
2
gregvaughn
I think you missed my point. I’m not talking about the supervisor of the registry (whose job is to keep the registry running), but the supervisor of your gun processes. That supervisor is given a child spec with a restart: :permanent like any other supervisor can receive, and it will restart your process when it dies. During your process’ startup, it can then register itself.
Docs for restart values are here in the Supervisor module Supervisor — Elixir v1.20.2
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bottlenecked
This still sounds like poolboy to me- unless each connection is to a different endpoint, in which case process registration like other people mentioned here would work better. But if you connect to the same (or just a couple) different endpoints and do not wish to pay upfront the cost of opening 10000 connections, you can do that lazily with poolboy using a small size with a large max overflow
1