A major financial institution recently completed a project to consolidate all of their employee information, including credentials for building and online access, into a single database. Of course, they protected their database with Oracle RAC and Oracle DataGuard, and had redundant infrastructure in their data center. However, they needed to address outages that might impact their entire data center, such as wide-area network or power failures. While they had a remote data center, it was too far away for synchronous updates , and there was concern about the delays inherent in log shipping. There was also concern about the load on both the master server and the network if all of the users had to make master data queries to one database.
After considering several alternatives, the group chose to use SharePlex to replicate their master data from a single "source of truth" to other databases. They set up SharePlex in a "hub and spoke" configuration, with their master database as the hub.
The project team started off by setting up a configuration that would replicate data from about 30 master tables to each of their 4 target databases; some of which were in the same data center, and some of which were remote.
This simple configuration provided each of the target systems with an independent copy of the master data. eliminating the need for database links, and SQL*NET traffic between systems. Also, even if the master system becomes unavailable, the target systems all still have access to the most up-to-date versions of the data.
In order to provide even more redundancy, the team identified one of the targets as a "secondary master". By establishing replication from the secondary master to the other systems, including the master, their master data could be maintained. If the main system was unavailable, changes could still be made to the secondary master, and would be propagated to the targets, and applied to the master once it became available again. The arrows in the diagram below show the replication paths.
Here's the configuration file used for the secondary master. Notice that the master is now one of the targets for this replication stream
By using SharePlex, the customer has ensured that their critical master data will be available; even if one or more of their systems fail. Learn more about our data replication tool.