This is an example application that shows how Horde.DynamicSupervisor and Horde.Registry work together.

Start the app in separate terminal windows with:

iex --name [email protected] --cookie asdf -S mix

and

iex --name [email protected] --cookie asdf -S mix

and

iex --name [email protected] --cookie asdf -S mix

You should notice the message HELLO from node X printing in just one of the instances. If you close that instance, you should (almost instantly) see the messages being output by the other instance.

We use the meta/2 and put_meta/3 functions on Horde.Registry to share the value for the counter across the members of the Horde. This means that when the node running HelloWorld.SayHello is killed, the new instance started by the Horde.DynamicSupervisor will pick up the counter from the meta data shared across the Horde.Registry to continue the count where the previous instance left off. You can get the count by running HelloWorld.SayHello.how_many?

You can also call HelloWorld.Application.how_many? from any of the IEX consoles to retrieve the current value of the counter.

Other than that, this is a very minimal example of what one would need to do to get up and running with Horde.