Which parts of HTTP/2 are stateful?

Question

Unlike the original stateless HTTP/1, HTTP/2 has many stateful components.

These parts of HTTP/2 are stateful:

• Header blocks refer to a stateful unsigned 31-bit integer called a stream identifier
• Frames also reference the same stateful stream identifier
• opportunistic encryption also depends on state since TLS is stateful

Are there any other parts of HTTP/2 that are stateful?

Liter

Possible duplicate of Is HTTP/2 a stateless protocol? – Rue

@Rue This question is older. Also, this question is asking about which components are stateful, not if the protocol is stateless. HTTP/2 is stateful, and this question assumes that the reader already knows this or can reasonably infer this from the first sentence. – Liter

@Rue Also, you are the author of the current answer, which I suspect gives concern for further bias. – Liter

you are just speculating on the subject, without understanding of OSI model. HTTP/1.0 is not stateful. The same is fully true about HTTP/2, as application layer still remains stateless... however it does have a few stateful components according to RFC. An HTTP/2 connection is an application-layer protocol running on top of a TCP connection. Don't mix it with session and transport layers. – Rue

@Farside. You are 50% wrong. HTTP/1.0 is stateless. No stateful mechanisms were defined by the original spec. You are correct as you say it was stateless. The addition of cookies add state on top of the original HTTP spec. HTTP/2.0 is stateful. HTTP/2.0 defines new stateful mechanisms in its standard. You don't have to use it statefully, but it's still there. I don't know how else to communicate this to you. This is a simple matter. And please, don't be a jerk and say things like "without understanding of OSI model". This is unbecoming of an Internet citizen. – Liter

Answer 1

HTTP 2 adds many stateful components to the HTTP corpus.

• Streams use a stateful unsigned 31-bit integer called a "stream identifier".
• Header blocks are used to statefully establish the stream identifier.
• Frames are stateful.
• Header compression is stateful.
• Opportunistic encryption is stateful.

The following are stateful components carried from previous HTTP additions which are still stateful in HTTP 2.

• Cookies are stateful.
• HTTPS is stateful.
• HTTP caching is stateful. (See also RFC 7234.)
• HTTP defined authentication is stateful. (See also RFC 7235)
• Web Sockets are stateful and use a stateful "Sec-WebSocket-Key" HTTP header.
• Web Storage, although not HTTP, is also stateful.

Liter