Running two or more Rails apps using Anycable in the same server

[Roko131]

Hi
So let's say we have app1.com, app2.com on a single server

So per docs I would need

anycable-go --host=localhost --port=8080
bundle exec anycable

# config/anycable.yml
development:
  redis_url: redis://localhost:6379/1
production:
  redis_url: redis://my.redis.io:6379/1

So for two apps:
Must I run anycable-go command twice? once with each host? I can use the same port right?
Or maybe I need to only run this command once? for both apps?

# option 1 single process for both apps
anycable-go --host=app1.com,app2.com --port=8080
# option 2 different host same port
anycable-go --host=app1.com --port=8080
anycable-go --host=app2.com --port=8080
# option 3 different host + port
anycable-go --host=app1.com --port=8080
anycable-go --host=app2.com --port=8081

Regarding redis - can I use the same redis_url?

# option1 same redis/port, same DB
redis_url: redis://localhost:6379/1 # app1
redis_url: redis://localhost:6379/1 # app2
# option2 same redis/port, different DB
redis_url: redis://localhost:6379/1 # app1
redis_url: redis://localhost:6379/2 # app2
# option3 different redis process, 
redis_url: redis://localhost:6379/1 # app1
redis_url: redis://localhost:6380/1 # app2

To summarize:

1. Can I use the same redis_url inside anycable.yml for both app1 and app2?
2. How should I go about running anycable-go --host=localhost --port=8080, Can I achieve it by using a single process call?

[palkan]

How should I go about running anycable-go --host=localhost --port=8080, Can I achieve it by using a single process call?

AnyCable server can connect only to a single backend application (the gRPC one you run via bundle exec anycable). So, you need to launch two anycable-go commands listening on different ports. Similarly, you must run bundle exec anycable with different --rpc-host. To sum up:

# app1
bundle exec anycable --rpc-host=localhost:50051
anycable-go --port=8080 --rpc-host=localhost:50051

# app2
bundle exec anycable --rpc-host=localhost:50052
anycable-go --port=8081 --rpc-host=localhost:50052

Can I use the same redis_url inside anycable.yml for both app1 and app2?

Yes, same Redis instance is fine, but it's better to isolate data streams by using different redis_channel values set in anycable.yml (and passed to the corresponding anycable-go server)