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I am trying to configure a reverse proxy with apache, but I am getting a No protocol handler was valid for the URL error, which I do not understand.

This is the relevant configuration of apache:

ProxyRequests Off
ProxyPreserveHost On

<Proxy *>
       Order deny,allow
       Allow from all

ProxyPass        /gonvaled/examples/jsonrpc/output/services/ http://localhost:8000/services/
ProxyPassReverse /gonvaled/examples/jsonrpc/output/services/ http://localhost:8000/services/

The requests is reaching apache as:

POST /gonvaled/examples/jsonrpc/output/services/ HTTP/1.1

And they should be forwarded to my internal service, located at:

These are the logs:

==> /var/log/apache2/error.log <==
[Wed Jun 20 02:05:20 2012] [debug] proxy_util.c(1506): [client] proxy: http: found worker http://localhost:8000/services/ for http://localhost:8000/services/, referer: http://localhost/gonvaled/examples/jsonrpc/output/JSONRPCExample.safari.cache.html
[Wed Jun 20 02:05:20 2012] [debug] mod_proxy.c(998): Running scheme http handler (attempt 0)
[Wed Jun 20 02:05:20 2012] [warn] proxy: No protocol handler was valid for the URL /gonvaled/examples/jsonrpc/output/services/ If you are using a DSO version of mod_proxy, make sure the proxy submodules are included in the configuration using LoadModule.
[Wed Jun 20 02:05:20 2012] [debug] mod_deflate.c(615): [client] Zlib: Compressed 614 to 373 : URL /gonvaled/examples/jsonrpc/output/services/, referer: http://localhost/gonvaled/examples/jsonrpc/output/JSONRPCExample.safari.cache.html

==> /var/log/apache2/access.log <== - - [20/Jun/2012:02:05:20 +0200] "POST /gonvaled/examples/jsonrpc/output/services/ HTTP/1.1" 500 598 "http://localhost/gonvaled/examples/jsonrpc/output/JSONRPCExample.safari.cache.html" "Mozilla/5.0 (X11; Linux i686) AppleWebKit/535.19 (KHTML, like Gecko) Chrome/18.0.1025.162 Safari/535.19"
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For me, on apache httpd 2.4, this happened because i was missing the trailing slash:

Did not work:

    <Proxy balancer://mycluster>
    ProxyPass / balancer://mycluster
    ProxyPassReverse / balancer://mycluster


    <Proxy balancer://mycluster>
    ProxyPass / balancer://mycluster/
    ProxyPassReverse / balancer://mycluster/

(added / at the end)

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For me, apache 2.2.15, <kbd>/</kbd> at the end works. THX! – Kompot Apr 7 at 7:18
up vote 15 down vote accepted

I found the problem. The proxy_http module needs to be activated too in Apache (I had only proxy_html and proxy)

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