Apache Module mod_proxy_http2

Summary

mod_proxy_http2 supports HTTP/2 only, it does not provide any downgrades to HTTP/1.1. This means that the backend needs to support HTTP/2 because HTTP/1.1 will not be used instead.

This module requires the service of mod_proxy, so in order to get the ability of handling HTTP/2 proxy requests, mod_proxy and mod_proxy_http2 need to be both loaded by the server.

mod_proxy_http2 works with incoming fronted requests using HTTP/1.1 or HTTP/2. In both cases, requests proxied to the same backend are sent over a single TCP connection whenever possible (namely when the connection can be re-used).

Caveat: there will be no attemp to consolidate multiple HTTP/1.1 frontend requests (configured to be proxied to the same backend) into HTTP/2 streams belonging to the same HTTP/2 request. Each HTTP/1.1 frontend request will be proxied to the backend using a separate HTTP/2 request (trying to re-use the same TCP connection if possible).

This module relies on libnghttp2 to provide the core http/2 engine.

Basic Examples

The examples below demonstrate how to configure HTTP/2 for backend connections for a reverse proxy.

ProxyPass "/app" "h2://app.example.com"
ProxyPassReverse "/app" "https://app.example.com"

ProxyPass "/app" "h2c://app.example.com"
ProxyPassReverse "/app" "http://app.example.com"

Request notes

mod_proxy_http creates the following request notes for logging using the %{VARNAME}n format in LogFormat or ErrorLogFormat:

proxy-source-port

The local port used for the connection to the backend server.

proxy-status

The HTTP/2 status received from the backend server.