High-Availability Clusters in a Hierarchical Tree Topology

With a hierarchical tree topology, parent servers are good candidates for using high-availability clusters to provide backup servers.

The following example is based on the example in Hierarchical Tree Topology.

If China fails, then Beijing and Shanghai can no longer replicate with other servers in the replication system; Guangzhou and Chengdu can replicate only with each other. However, if China was part of a high-availability cluster, when it failed, the secondary server would replace it and replication would continue, as illustrated in Hierarchical Tree Topology with HDR.
Figure 1: Hierarchical Tree Topology with HDR

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In this example, Asia and Guangzhou, which are also parent servers, might also benefit from using a high-availability cluster to ensure high availability.