Httpd mod proxy Installation

Internal

• mod_proxy

Overview

This article decribes mod_proxy installation. For concepts, see "mod_proxy Concepts". For configuration reference, see "mod_proxy Configuration".

Load the Modules

LoadModule proxy_module modules/mod_proxy.so
LoadModule proxy_http_module modules/mod_proxy_http.so
LoadModule proxy_ajp_module modules/mod_proxy_ajp.so
LoadModule proxy_balancer_module modules/mod_proxy_balancer.so

Note that the modules must be compiled as dynamic modules and available. For more details on dynamic modules, see Static Modules vs. Dynamic Modules.

For a list of required modules and an explanation of how they work together, see mod_proxy Modules and How they Work Together.

Declare the Proxy Worker

Direct Worker

Direct Workers

Direct workers proxy to just one backend node.

Come up with the example when I need it.

Balancer Worker

Balancer Worker

Balancer workers proxy to a pool of load-balanced backend node.

Trailing Slash

The trailing slash on the balancer URL (in this case "balancer://mycluster/") is important so that the URLs are properly resolved while being proxied. Note that without a training slash, if the "/example" is requested, the URL will become "balancer://myclusterexample". No such balancer exists, and the request will fail with a 500 response. With the trailing slash, it'd resolve as "balancer://mycluster/example", which will allow to correctly locate the balancer.

Prevent Proxying for Certain URLs

In order to prevent proxying for certain URLs, additional ProxyPass directives can be specified as follows:

ProxyPass /this-wont-be-proxied !

ProxyPass and ProxyPassMatch rules are checked in the order in which they were specified in the configuration file, and the first rule match wins. That is why the declaration of the URLs for which we want to prevent proxying should be specified at the top of the list. For more details on ProxyPass processing order see:

ProxyPass Processing Order

ProxyPassReverse

TODO httpd ProxyPassReverse

Specify the Balancer Topology and Configuration

<Proxy balancer://mycluster>
    BalancerMember http://my-node1:port1/ route=node1
    BalancerMember http://my-node2:port2/ route=node2
</Proxy>