Mod_proxy_http2 - got a 503

[Olivier Mallassi <olivier.mallassi@xxxxxxxxx>]

Hello all

We are trying to use the mod_proxy_http2 of httpd. Our use case is for now "simple"

- multiple backedns (configured in HTTP2)

- one httpd acting as proxy 

-- mod_proxy_http2 is activated

-- we use the Balancer directive to load balanced accross backends (round-robin)

- the client is a curl -kv --http2 ...

The tests are the following:

- while using curl to access one of the backend directly, the access log shows that we use HTTP/2

- then the balancer directive is configured with http://mybackend1

In taht case, while accessing to the proxy with curl, we see that the communication between curl & httpd is HTTP/2 but that the communication with the backends is HTTP1/1

- then we change the balancer directive to h2://mybackend.... 

In that case, the curl returns 503 (like if the proxy is unable to route). 

I suspect a misconfiguration but any help is welcomed. Does someone already did something similar? 

thanks.