Is there an example of using HTTP/2?

[Nikaidou-Shinku]

I tried to enable the http2 feature flag and used http2_only(true) but failed, my browser reported ERR_INVALID_HTTP_RESPONSE. Then I tried to disable the default features and enable the http2 and tokio, but failed again.

I find nothing about HTTP/2 in the examples folder. Can someone give me an example?

[davidpdrsn]

I suspect the browser isn't actually connecting with http2. Hyper does not support upgrading http1 to http2, so you have to connect with http2 right away.

Try with curl's --http2-prior-knowledge option.

It does indeed work because tonic uses axum and http2.

[Nikaidou-Shinku]

Thank you! I may need to learn more about how http2 works, since I don't seem to understand it well.

I tried --http2 before but failed, and I just checked the curl manual and learned that this option is also upgraded from http1.

[FrankReh]

This answer and this one, both on superuser.com, seem useful in understanding how to get a browser to use HTTP/2. It is my understanding that to use HTTP/2 from a browser, one needs to be connecting to the server over https(TLS).

As part of the TLS negotiation, the browser learns the server supports HTTP/2 and generally will then try to use it first over the TLS connection.

Some browsers have a way to skip their TLS requirement for accessing localhost domains but that requires searching online for what to do for each combination of browser and OS that one is on.