Multiplexing is a pretty cool feature of http/2. It allows using one connection to serve multiple requests from a single client simultaneously.

My question is: does this multiplexing feature violate REST API rules?

1. I understand that REST API enforces request-response architecture, but multiplexing without server-push (streaming) feature enabled is essentially one request -> one response paradigm, so that's not a violation, is that right?
2. REST API also enforces stateless, and I'm lost there: is multiplexing through a single connection considered as stateful or stateless?

If I want to upgrade a REST API which is currently implemented with HTTP/1.1 to use HTTP/2, do I have the privilege to use the multiplexing feature, or I have to do stream after stream (req1, res1, req2, res2...)?

CodePudding user response：

Network multiplexing and REST API are two absolutely different matters/layers of responsibility.

Multiplexing is about how do communication signals flow, and not about what is the architectural pattern of HTTP messages' communication (which is what REST is all about).

From the REST perspective, it does not matter:

1. how electrical signals flow in the cable or wirelessly;
2. what type of cable or other physical mean you use for transferring data;
3. even if you maintain a single physical (TCP) connection throughout several request-response cycles or you open and close TCP connection per each HTTP request-response;
4. even if you use something else than TCP (yes, that's not a good idea, but theoretically, as long as communication is ensured to have integrity, consistency and stability (which is all TCP brings), it doesn't much matter how the physical connection is established).

Because,

REST is an architectural (design of the web application) pattern for implementing web applications.

Multiplexing is about how the physical signals/connection is being implemented.

As long as HTTP messages flow seamlessly between client and server, physical or transport layer have nothing to do with REST endpoints; hence, there is nothing in multiplexing, that can violate anything in REST, as - again: these two serve absolutely different purposes.