What must be defined for all MID Servers in a cluster?

The correct response highlights that capabilities must be defined for all MID Servers in a cluster. In the context of ServiceNow MID Servers, capabilities refer to specific functions that a MID Server can perform, such as interacting with various systems, executing scripts, and handling certain protocols. Defining capabilities is essential for the functioning of the cluster because it allows the ServiceNow platform to efficiently route tasks to the most appropriate MID Server based on their available capabilities. This ensures optimal performance and resource utilization across the cluster.

Effective capability management also plays a critical role in load balancing and fault tolerance, as it enables the system to understand which MID Server can handle a specific request, thus maintaining efficient workflow and system reliability. Without properly defined capabilities, the cluster may struggle to allocate tasks effectively, which could lead to performance issues or task failures.

While other options, such as service level agreements, database connections, and authentication methods may be important in their own right, they do not directly relate to the core requirement for MID Servers in a cluster to perform their designated tasks effectively.