What is the minimum setup required for high availability in Appian software engine failover?

The minimum setup required for high availability in Appian software engine failover is a cluster with 2 engine nodes. High availability aims to ensure that the application remains operational even if one of the nodes fails, minimizing downtime and service disruption.

With just one engine node, if that node were to fail, the application would experience downtime since there would be no backup to take over. However, with two engine nodes within a single cluster, if one node fails, the other can continue functioning, thereby maintaining operational continuity. This setup allows for load balancing and redundancy, essential features in high-availability configurations.

The other configurations that involve three or four nodes go beyond the minimum requirement, providing additional redundancy and load distribution, but are not necessary to achieve the basic level of high availability. Thus, having at least two engine nodes is the simplest and most effective way to ensure failover capability in Appian.