What are the best use cases for distributed actor model solutions? Im just slightly familiar with it and it’s on my learning list. Anybody here have any experience with it? How about with Goblins?
I was recently trying to answer this question while playing around with Dapr (amazing project by the way).
So despite it being a solution that has existed for distributed systems since the 70s I was watching a talk from Microsoft on the topic where they would refer to actors as “cloud native objects” and the model itself as an ideal way to do OOP on distributed systems. The marketing feels a little cringe at first but the mental model works well.
I have an object which contains some state. Normally I would be responsible for managing the entire lifecycle of this object including resolving race conditions for DB writes and a million other problems that make distributed systems difficult. With many modern implementations of the actor model however (Microsoft have done a lot of interesting stuff here building Azure and Xbox games like Halo using Actors heavily) you don’t have to worry about any of this. You can just call the object as though you had unlimited RAM and it was in memory for you and race conditions were no longer a thing that you had to worry about.
> I was watching a talk from Microsoft on the topic where they would refer to actors as “cloud native objects” and the model itself as an ideal way to do OOP on distributed systems. The marketing feels a little cringe at first but the mental model works well.
I started referring to Grains as Cloud Native Objects as a way to better convey them to people who aren't familiar already. My view is that Grains are different enough from Erlang/Akka style actors that lumping them under the Actor terminology can cause confusion. In the research publications, the term Virtual Actor is coined, which better describes them.
The use case for actors is any time you want to distribute work across multiple nodes. In general, actors are a great concurrency model that simplifies a lot of the complexity of distributed programming.
I don't want to distract from this comment, because I think it's spot on, but I think another interesting use for actors is as one of the few sane concurrency models for mutation. Pony does this - objects are actors by default. Things can act concurrently without fear external to an object, but all mutations within a given object are serialized. Seems like a nice set of defaults.
The author posted some interesting applications using Goblins (a video game and chat app). There is some interest in porting Goblins to Guile Scheme to integrate with GNU Shepherd (a service orchestrator) ... somehow.
