In the Enterprise Server With Replica(s) topology, a replica is a node containing a copy of data from the primary node.
Replicas provide data protection and read scaling.
Enterprise Server With Replica(s)
Initial Replica Count
Initial replica count is defined at time of service launch.
By default, this topology can be launched with as few as 0 replicas and as many as 4 replicas.
With auto-scaling of nodes, Out/In (horizontal) scaling of replica count can be triggered automatically based on load. This feature can be enabled or disabled during service launch or after launch.
Replica count can be manually changed after launch using Self-Service Operations.