Core Issue
The Install.log shows a fatal error when the database cannot connect to the publisher database because it cannot resolve the hostname.
Resolution
In order to resolve the issue, add the subscriber to the database on the publisher with the IP address as the hostname. Then, attempt to install again with only the IP address of the publisher as the hostname.
Also, it is required to keep the IP address and hostnames on the Cisco CallManager 5.x servers exactly the same as it is on the Cisco CallManager 4.x servers, and if the Dynamic Host Control Protocol (DHCP) is to be used, make sure that the same IP is assigned and that Domain Name System (DNS) resolves that IP to the related hostname.
Refer to Installing Cisco Unified CallManager Release 5.0(4) for more information.