On Thu, Feb 22, 2024 at 12:47:04PM +1100, Miles Hampson wrote: > 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)
Alas for the moment HTTP/3 upload are limited indeed by the flow control which is equivalent to tune.bufsize. To remove this limitation, I wish to implement a multi-buffer receive per stream, but for now this is not yet planned. -- Amaury Denoyelle
