HTTP2 protocol only works on systems with OpenSSL 1.0.2 or later. Hence, you can enable it on Debian 9, Ubuntu 16.04, RHEL, or CentOS, but not on Debian 8, Ubuntu 14.04.
To enable support for HTTP/2 on a front-end server, you configure the bind line in the configuration file's frontend section as an
ssl endpoint, and
alpn must announce
h2, as follows:
frontend f_myapp bind :443 ssl crt /path/to/cert.crt alpn h2,http/1.1 mode http
When you expect large file uploads over a network with moderately high latency, you may experience slow upload speeds. You can increase the HTTP/2 Flow Control window size to allow HAProxy to buffer more data. Set
tune.h2.initial-window-size in the
global section to a value like 1048576.