Service Mapping Mid Servers

tim_sewell · ‎03-10-2016

How does Service Mapping decide which Mid Server it will use for an end point?

I have 2 Mid Servers configured in different domains, 1 for our Prod domain and 1 for our Test domain. I created a new business service with an end point to a Web server in the Prod domain. I would assume that Service Mapping would recognize the domain and choose the correct Mid Server to discover with. It does not seem to be the case, as the discovery fails with a "Failed to communicate with the WMI collector service on localhost." message.

If I disable the Test domain Mid Server, and run the discovery again, it maps the Web server correctly. If I start up the Test domain Mid Server service, it fails again... This leads me to believe that Service Mapping is choosing the Test domain Mid Server by some property or setting. I have searched all of the documentation I can find on Service Mapping, but I cannot see where this setting may be. Other steps I have tried:

Removed ALL credential affinities and ran a regular ServiceNow Quick Discovery on the Web server, to establish affinity between it and the Prod domain Mid Server.
Created a Mid Server IP Range, including the IP of the Web server and assigned it to the Prod domain Mid Server.
I assigned the Prod domain Mid Server to be the default Mid Server for Orchestration activities

What am I missing?

jonathanjacobcp · ‎03-15-2016

Hi Tim,

See the following KB article on hi:

ServiceNow Customer Service System

Improving MID Server selection algorithm

Problem

Service Mapping creates discovery requests that contain the IP address of the entry point, the probe and the MID Server. Service Mapping then writes them in the ECC Queue table of CMDB (ecc_queue).

In Geneva patch 1-4, Service Mapping selects MID Servers for discovery requests using only IP ranges. If a MID Server does not have a defined IP range, Service Mapping treats it as suitable for any IP range and therefore can assign any discovery request to it. In a situation where there is a MID Server with the IP range matching the discovery request and a MID Server with no defined IP range, Service Mapping may select the MID Server with no defined IP range.

Symptoms

Service Mapping may not discover the CI from the entry point.

Imperfect algorithm for MID Server selection in Service Mapping.

Resolution

The algorithm of selecting MID Servers for discovery requests is improved in Service Mapping starting with Geneva Patch 5. We recommend that customers using earlier versions install a business rule that improves MID Server selection.

The business rule changes the algorithm to the following:

(Optional, needs to be configured) Service Mapping can assign discovery requests only to MID Servers configured to work with Service Mapping
Service Mapping uses only MID Servers with defined IP ranges
If there are any entry points with IP address that does not match any defined IP ranges in MID Servers, Service Mapping assigns the discovery request for this entry point to the default MID Server
If there is an entry point with no IP address (using hostname, such as http://www.google.com), Service Mapping assigns the discovery request for this entry point to the default MID Server

As a result, Service Mapping cannot randomly assign requests to MID Servers with no defined IP range.To install and configure this business rule, perform the following steps:

Install the business rule by importing the MIDBusinessRule.xml file attached to this KB article.
To use only MID Servers configured to work with Service Mapping:a. Navigate to the System Property table and click New.b. In the Name field, enter sa.service_mapping.use_capabilities.c. From the Type list, select true|false.d. In the Value field, enter true.e. Click Submit.
To select a MID Server as the default MID Server for Service Mapping:

a. Navigate to the System Property table and click New.

b. In the Name field, enter mid.server.sm_default.

c. From the Type list, select string.

d. In the Value field, enter the name of the MID Server to use as the default.

e. Click Submit.

For more information about business rules, see Business Rules.

View solution in original post

tim_sewell · ‎07-26-2018

They have definitely made it much easier since I initially posted this question.

Runjay Patel · ‎12-15-2020

Check out this video, it will clear all your doubts and help you to understand mid server in details. It will help you resolve below queries:

Link: https://youtu.be/RMXhYJxPMPU

Mid Server Installation step by steps
Mid Server Troubleshooting for all version.
I am unable to install mid server.
Unable to configure MID server.
Service Mapping Mid Servers.
How to log in to the Mid server using the Credential.
MID Server for multiple sub production instances.
Why do we use MID server? Purpose of using MID Server?
How to define a specific mid server for the discoverIpAddress () function?
Other issues.

Runjay Patel · ‎12-20-2020

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

Link: https://www.youtube.com/watch?v=VN33mZiHBj0&t=1s&ab_channel=ServiceNowHelpdesk

It help you to understand below points.

Service Mapping Overview
Service Mapping Plugins Required
Service Mapping roles management
Service mapping credentials for different ci type
Verify that Service Mapping is set up properly (Readiness)
Service Mapping setup step by step
Service Mapping troubleshootings

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

Awadhesh Kumar1 · ‎12-27-2020

Thanks Runjay. Awesome tutorial. Now i understood the SM concept.