[Rdo-list] Troubleshooting services after reboot of the overcloud

Hello. I rebooted all my overcloud nodes. This is a Mitaka installation with rdo-manager on a virtual environment. The keystone service is not answering any more, and I have no clue what to do about it now that it's running under Apache. The httpd service itself is running. How do I troubleshoot this? Thanks, Udi.