Using HTTP2 without TLS

[siddhsql]

I am new to httpx and trying to use http2 without TLS. My server is Spring Boot running embedded Tomcat as explained [here]. I verified a sample request returns HTTP2 using curl:

$ curl --http2-prior-knowledge -I http://localhost:8080/
HTTP/2 200
vary: Origin
vary: Access-Control-Request-Method
vary: Access-Control-Request-Headers
content-type: application/json
date: Sat, 06 Apr 2024 17:33:17 GMT

but when I try to use httpx according to [1] this is what I get:

>>> client = httpx.AsyncClient(http2=True)
>>> response = await client.get("http://localhost:8080/")
>>> response.http_version
'HTTP/1.1'

so it seems it not using http2. How can I get it to use http2? this is the first time I am trying httpx so apologies if I have overlooked something.

[lovelydinosaur]

To force HTTP/2 prior knowledge, use...

>>> client = httpx.Client(http1=False, http2=True)

[siddhsql]

thanks. it seems to work: ```

>> client = httpx.AsyncClient(http1=False, http2=True) >> response = await client.get("http://localhost:8080/$") >> response.http_version

'HTTP/2' ``` but then shouldn't this be the pattern to use? If one uses ```

>> client = httpx.AsyncClient(http2=True)

``` then even if server supports http2, we are using http1 which is suboptimal.

…

On Sat, Apr 6, 2024 at 11:50 AM Tom Christie ***@***.***> wrote: To force HTTP/2 prior knowledge, use... >>> client = httpx.Client(http1=False, http2=True) — Reply to this email directly, view it on GitHub <#3161 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A6NWEK3V6JFDHKGNZQP5RVTY4A7WNAVCNFSM6AAAAABF2TJRX2VHI2DSMVQWIX3LMV43SRDJONRXK43TNFXW4Q3PNVWWK3TUHM4TAMZRGI3DA> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[lovelydinosaur]

HTTP/2 is typically only supported over HTTPS, not HTTP. Specifying http2=True ensures that the client requests either HTTP/1.1 or HTTP/2 during the SSL setup (using the ALPN protocol), and the server responds with whichever is supported.

If you want to force HTTP/2 support for a plain HTTP connection, you need to explicitly disable HTTP/1.1. ("prior knowledge" that HTTP/2 is supported, without requiring that info in the SSL handshake)