In this scenario, an enterprise has two major data centers, one in London and the other in New York, separated by a WAN. The scenario assumes that the network is very busy during normal business hours.
In this scenario, the Number of hosts has been calculated to be eight. A fully connected, 4-way multi-master topology is deployed in each of the two data centers. These two topologies are also fully connected to each other. For ease of comprehension, not all replication agreements between the two data centers are shown in the following diagram.
The replication strategy for this scenario includes the following:
Master copies of directory data are held on servers in both data centers.
A multi-master replication topology is deployed between the data centers to provide high availability and write-failover across the deployment.
Replication across the WAN link is scheduled so that it occurs only during off-peak hours to optimize bandwidth.
To increase performance, client applications are directed to local servers. Clients in the U.S. read from and write to masters in the New York data center. Clients in the UK read from and write to masters in the London data center.