Getting Started with Microsoft Orleans

Orleans is an open source actor framework built by Microsoft research, and was used for halo cloud functionality! What is an actor framework? Another popular .net actor framework is AKKA.net, though I’ve not worked with it — and barely Orleans for that matter. Anyway…

From Wikipedia:

The actor model in computer science is a mathematical model of concurrent computation that treats “actors” as the universal primitives of concurrent computation. In response to a message that it receives, an actor can: make local decisions, create more actors, send more messages, and determine how to respond to the next message received. Actors may modify their own private state, but can only affect each other through messages (avoiding the need for any locks).

Why should I care about Orleans, or actor model frameworks in general?

In a monolithic system, you can more or less only scale “up”. With systems built using microservices, actors, etc, you have the option of scaling “out”. What does scaling “up” vs “out” mean? To scale a system up, means adding more RAM, more CPU — more resources, to the hardware in which your system runs; but you are still constrained to a single “box”. To scale “out” means you can just add a brand new machine, generally to a “cluster” of some sort, that allows your system to much more easily add additional resources. Sure, you can always add more RAM/CPU to your existing machines in a microservices system, but you…