7 ms·

Erlang?

• SuddsMcDuff 9y ago
  More generally, the actor model (https://en.wikipedia.org/wiki/Actor_model https://en.wikipedia.org/wiki/Actor_model)
  • cturner 9y ago
    It is not a complete match. A quality of the actor concurrency model is unreliable message delivery. The system described in the post could be done with reliable delivery expectations.
• Jtsummers 9y ago
  Kind of. The proposal in the link is more pub/sub than Erlang offers by default (you can do this in Erlang, but it's not the typical way). So with the article's presentation they're using a message bus that multiple subscribers can listen to. So you send a message X and subscribers A, B, C each receive it and do the right thing. A may be a logger, just track that an X was sent and when. Useful for metric gathering and tracking, but can be disabled (it's unneeded from a functional perspective). B may contain some actual business logic, take X and transform it into a Y and broadcasting this new message. If we need to change how Y is constructed we can come directly here. C may use X to update values in a database. Isolating it here allows you to easily replace the DB backend. Create a D process which handles the new database, evaluate that it's working correctly (by comparing to the database C is using) and then disable C later. These 3 processes are all listening to the same message broadcast. in Erlang we'd need one process which received X and rebroadcasts to an arbitrary number of subscribers (again, easily doable, but not the default behavior people go for). In Go you have channels you can pass around, but as I understand once read the data is removed so only the first subscriber gets it. You'd similarly need some "bus" intermediary that took the input from one channel and rebroadcasts on subscriber channels. Really, they're describing CORBA and similar systems.