Hi, I have noticed that transferring large files with http/2 to a backend server through HAProxy 2.9 (and earlier) over a network link with a bit of latency can be extremely slow unless the HTTP/2 Flow Control window size is increased quite a bit (i.e. 4x the default works well in our situation).
We are now trying out http/3 and hit the same issue. I don't think there is any connection migration, this is just from a test server. There don't seem to be any tune.h3 settings in the config manual, are there any connection settings that I might be able to adjust to improve this situation? I haven't investigated much so far because I don't have any understanding of how QUIC stream flow control works yet, so the only thing I have tried is increasing the QUIC receive buffer (this is on an Ubuntu 22.04 server) Thanks for your time, Miles
