When trying to purchase a subscription in online store and navigating to order page, there is a message Loading subdomain form... and loading never completes. If open browser debug console and reload page, it is seen that GET request below fails with HTTP 503 error:
Either online store store.example.com HTTPS virtual host is misconfigured or some network issue preventing online store from connecting to Billing node.
Make sure that billing node accepts connection on port 443 from the online store:
[root@pba-store]# telnet 172.16.0.15 443 Trying 172.16.0.15... Connected to 172.16.0.15. Escape character is '^]'. ^]
Check if port 443 is specified in
[root@pba-store webroot]# grep ProxyPass /etc/httpd/conf.d/ssl.conf ProxyPass /aps https://172.16.0.15:443/aps
If port is incorrect, change it to 443 and reload Apache:
[root@pba-store webroot]# service httpd reload