On-premise HA search supports two kinds of HA configurations: single data center and multiple data centers.
You can configure your on-premise search nodes in either of these HA configurations:
To understand what you'll need for your HA search configuration, be sure to read Capacity and Scaling
Considerations and Required Nodes for an On-premise
HA Search Service.
The following diagram shows the simplest HA configuration for search. You might also find it helpful to understand how a single on-premise search node works before diving into Configuring the Search Service for High-Availability.
