My HAProxy 1.9.x instance is receiving a mix of HTTP/1.0 and HTTP/1.1 requests from clients (clients are mostly things like curl, wget and http libraries, not web browsers).
I can see from the logs that when HAProxy receives a HTTP/1.0 request from a client, it makes a HTTP/1.0 request to a backend. I.e., it doesn’t convert it to HTTP/1.1 before handing off to the backend. This is messing with keepalive connections to the backend: for HTTP/1.0 requests, the backend server (nginx) returns a “Connection: Close” response header, and Haproxy closes that specific connection.
Is it possible to tell Haproxy to only ever make HTTP/1.1 requests to backends?
I’m aware of the possibility to use HTTP/2 to backends with http-use-htx. But I’d like to keep things plain and simple if possible.