How HTTP/2 affects the implementation of a proxy server? Especially, for example, when a client sends an HTTP/2 request to a content server that only supports HTTP/1.x, should the proxy server tranform the HTTP/2 request to HTTP/1.x request before directing the client request to the content server? And upon receiving response from the content server, should the proxy server transform the response to the HTTP/2 format before sending it back to the client?
HTTP/2 enables full request and response multiplexing. In practice, this means a connection made to a web server from your browser can be used to send multiple requests and receive multiple responses. This gets rid of a lot of the additional time that it takes to establish a new connection for each request.
HTTP/2 is backwards compatible, browsers that do not support HTTP/2 will fallback to using HTTP/1.1.
A reverse proxy is a server that sits in front of web servers and forwards client (e.g. web browser) requests to those web servers. Reverse proxies are typically implemented to help increase security, performance, and reliability.
HTTPS proxies were invented to ensure communication with end-to-end security. In this flow, the client sends a special request to the proxy with the CONNECT verb. The proxy builds an opaque tunnel by connecting to the requested server using TCP and nothing else.
As dsign discussed, your understanding is correct.
However I thought it was worth pointing out there are still massive advantages to HTTP/2 at your edge connection (i.e. Your reverse proxy) as the issues HTTP/2 solves (primarily latency) are less of an issue over the typically shorter, typically high bandwidth hop from the reverse proxy to the content server.
For example if you have a 100ms delay to the reverse proxy at the edge and only 1ms delay between the reverse proxy and the content server, then the fact the content server is speaking HTTP/1.1 to the proxy server probably won't have much impact on performance due to the super fast 1ms latency. So the end client (speaking HTTP/2 to the reverse proxy) still sees a massive performance boast over HTTP/1.1.
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With