Thanks for posting the manifesto. Can anyone who is a guru in distributed computing explain to me how Reactive Streams is different from regular message queue architecture such as RPC or pub-sub with message header filtering (e.g., RabbitMQ, zmq)? Much appreciated.
Not really a guru, but RPC is traditionally not thought of a message queue architecture -- it's almost always built around a request-reply cycle with no queueing.
Reactive Streams seems to really boil down to a push-based (Functional?) Reactive Programming (with some queueing added in in the distributed case). As Erik Meijer explains[1], it's mostly about a small extension to the "Observer" pattern which comes about if you dualize the "Iterator" pattern properly.
EDIT: In short, there's very little really new under the sun here in CS terms, but this approach seems to be going through a hype cycle at the moment.
Thanks for clarifying RPC's specific socket-level implementation details and how Reactive Stream relates to the Observer/Iterator pattern.
Tbh, I tried to use Akka and RxJava for a bit but found it to be a bit cumbersome and ended up implementing pub-sub by way of ZeroMQ and Google Protobuf. I suppose I won't be able to leverage features such as composability and filtering on the message stream though. But I didn't like how the Reactor pattern implementation was a black box where I didn't know what was going on under the hood. Wish the best of luck to both teams however.
IMO at very high level both a pub-sub and stream based system is the same thing. Both are event driven.
But it differs at implementation level. A pub-sub is discrete, not composable and time (or latency or whatever you call it) is captured indirectly through state.
While a Stream is continuous, composable, transformable and time is the first class citizen.
My guess: this about having the benefits of third-party queue architectures directly in the JVM. I believe Java shops are only comfortable with Java-everywhere, so it's much more interesting for them to have it without depending on other tools.
