8.1 Overview

You must take database backup and restore it either on the same or a different cluster. It uses the Policy database (MySQL NDB Cluster) to run any command or to follow any instructions.

Database Model of CNC Policy

Policy database consists of the following two data types:

• Configuration Data: The configuration data is exclusive for a given site. Thus, an exclusive logical database is created and used by a site to store its configuration data. Using CNC Console and Configuration Management service, you can configure the data in the respective site only.
• Session Data: The session data is shared across sites. Thus, a common logical database is created and used by all sites. The data is replicated across sites to preserve and share session with mated sites. In case of cross sites messaging or a site failure, shared session data helps in continuity of service.

The following image shows the Policy database model in three different sites:

Figure 8-1 Database Model