What is the primary factor in determining the number of MID Servers required for a standard ServiceNow deployment?

The primary driver for determining the number of MID Servers is the expected workload. This workload is a function of the number of target devices or endpoints (e.g., servers for Discovery, integration endpoints) and the frequency and intensity of the interactions (e.g., how often Discovery schedules run, the volume of integration transactions). High transaction volumes or scanning a large number of CIs requires more MID Server resources (or more MID Servers) to process the jobs efficiently and avoid performance bottlenecks.

A. The number of network routers in use: The number of network devices is irrelevant to MID Server capacity planning; only the ability to route traffic to targets matters.
C. The number of concurrent users on the instance: MID Servers handle asynchronous, agent-less tasks and are not directly impacted by the number of interactive users on the instance UI.
D. The geographical spread of the organization: While geography can be a factor for network latency or security domains, the workload within those domains is the primary sizing factor.

1. ServiceNow Product Documentation. "MID Server system requirements". The documentation emphasizes that requirements are "dependent on the solution that the MID Server will be supporting" and provides guidance based on the workload of applications like Discovery and Orchestration.

2. ServiceNow Technical Best Practices. "MID Server Sizing and Performance". This guide explicitly states that sizing depends on "the number of devices to be discovered" and "the frequency of discovery," directly linking workload to MID Server requirements.