Administration · LessonBy Sneha I, ServiceNow Trainer, 8 yrs · Published · ServiceNow · all levels
MID server
What the MID server does, where to install it, how to size a cluster and how to keep it healthy.
Quick answer
What the MID server does, where to install it, how to size a cluster and how to keep it healthy.
Key takeaways
- MID servers make outbound connections only, no inbound firewall rules
- Use clusters for failover and load balancing
- ECC queue growth is the first sign of trouble
- Capabilities and IP ranges control job routing
Purpose
The MID server is a Java service that runs inside your network. It polls the instance over HTTPS for work, executes it locally, and posts results back. Nothing needs to be opened inbound through the firewall.
What runs on it
Discovery probes and patterns, Service Mapping, orchestration activities, integrations to internal systems, LDAP reads, and JDBC data sources. Capabilities and IP ranges decide which MID server picks up which job.
Sizing and health
Treat MID servers like any other server estate.
- Two MID servers per network zone gives you failover through a cluster
- Watch the ECC queue for growth, a backlog means the MID is undersized or offline
- Keep the service account permissions documented, they are audited
- MID servers auto upgrade with the instance, so plan a restart window
Practice challenge
+0 XPStreak ×0
Question 1 of 2
How does a MID server receive work?
Frequently asked questions
Does a MID server store our data?
It processes data in memory and writes results to the ECC queue. Keep the host patched and restricted like any system that handles credentials.
How many MID servers do we need?
Start with two per network zone that must be reached, then scale on ECC queue latency and Discovery duration rather than on a fixed ratio.