Apache in Centos 6 "ap_proxy_connect_backend disabling worker for (localhost)"

I am trying to connect to an application server that is on a virtual machine with Centos 6 , it has apache installed and I am placing the server ip in a browser from my pc, but when I try to connect I get the error 503 "Service Temporarily Unavailable " and in the apache log I get the error "ap_proxy_connect_backend disabling worker for (localhost)" . I've also tried with the command "/ usr / sbin / setsebool httpd_can_network_connect 1" but it has not worked, my hostname is "sagir.guadaltel.es" and in the httpd.conf file configure the ServerName as "sagir.guadaltel.es". In the vhost I have configured in this way

        ProxyPass ajp://localhost:8109/TrewaAdm
        ProxyPassReverse ajp://localhost:8109/TrewaAdm



        ProxyPass ajp://localhost:8109/sagir
        ProxyPassReverse ajp://localhost:8109/sagir



        ProxyPass ajp://localhost:8209/sagir2
        ProxyPassReverse ajp://localhost:8209/sagir2

What could this error be? Thank you very much.