Compared with HTTP1.X, HTTP/2 can make a response faster and more efficiently. It features the following advantages:
CLB supports the HTTP/2 protocol by default with no extra fees charged.
The listener supports HTTP/2 on HTTPS by default with no additional configuration required.
During the handshake process of HTTPS, the protocol version will be negotiated. The client uses ALPN (Application-Layer Protocol Negotiation) to inform the server of a list of supported protocols. The server selects HTTP/2 or HTTP1.X according to the protocol list. It is automatically backward compatible with no additional configuration required.
- Plaintext HTTP/2 is not supported. Mainstream browsers and web servers only support TLS-based HTTP/2 protocol.
- The HTTP1.X protocol is still used between CLB and real server.
HTTP/2 is supported in regions such as Beijing, Shanghai, Guangzhou, Hong Kong (China), Silicon Valley, Frankfurt and Mumbai.