Discovery Schedule - Mid Server field importance

[ravipoli]

Hello,

Quick question regarding Discovery schedule.

Scenario : I have configured a discovery schedule, left 'Behavior' field blank, Updated 'Mid Server' filed with 'PROD MID SERVER1' which is up and running.

Findings : When I ran this discovery schedule, I verified ECC Queue, interestingly I found PROD MID SERVER1 AND PROD MID SERVER2 are showing up in agents list.

Question : When I specify only 'PROD MID SERVER1' for 'Mid Server' field in Discovery schedule, how come PROD MID SERVER2 also participated   ?

Thank you

[JBark · Accepted solution]

The Cluster is the top level, any discovery setup to run by a single cluster member will use all MIDs in that cluster for that discovery. Scheduled Discoveries don't really see the cluster, so it makes it easier in my opinion to setup a large discovery schedule just by picking out one MID from the cluster.

I have 3 hosts with 9 MIDs so I've striped 3 load balanced clusters across the 3 hosts.

Host1 - MID1, MID2, MID3

Host2 - MID4, MID5, MID6

Host3 - MID7, MID8, MID9

Cluster1 - MID1, MID4, MID7

Cluster2 - MID2, MID5, MID8

Cluster3 - MID3, MID6, MID9

This setup gives me redundancy against host issues so that scheduled discoveries still have a chance to complete if 1 host is down. All discoveries are setup to use the 1st MID in the cluster.  

[Runjay Patel]

Check out this video, it will clear all your doubts and help you to understand Discovery queries in details.

Link: https://www.youtube.com/watch?v=30JbWVsusyE&t=10s&ab_channel=ServiceNowHelpdesk

It help you to understand below points.

• Discovery Overview
• Discovery prerequisite
• Understanding Discovery Phases in details
• Discovery credentials and IP Affinity
• Mid Server Management with Cluster and Load Balancer
• Schedule jobs
• Set up discovery from scratch to end
• Live implementation with real world data.
• Troubleshooting on various aspects
• Many more other issue related to mid server, CIs
• Cloud discovery
• Service Mapping

Please mark reply as Helpful/Correct, if applicable. Thanks!!