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

Alicia13 · ‎07-26-2018

Tim,

Thank you for your help. I'm wondering if I could pick your brain a bit more. I've probably spoken with at least 60 ServiceNow Developers. Our client has asked us to ask each one some preliminary questions and absolutely no one can answer them.

Would you mind looking at these and letting me know if they make sense? I find it hard to believe that no one can answer them. Each of these folks had at least a bit of experience with Discovery and Service Mapping.

They have provided me with the answers they are looking for (which none of the SNOW folks have been able to supply):

1. Can you please provide one Service Mapping entry point type?
Answer: Either one of the following.
· HTTP(s) or Web
· SQL or Database (could be Microsoft SQL, MySQL, Oracle, or any other)
· SharePoint
· TCP/IP (Generic)

2. What is the other known name for Vertical Discovery?
Answer: Top-Down Discovery - this is the discovery technique used by Service Mapping that finds and maps CI that is part of Business Service

3. What Service Mapping Role needs to be assign to a user that will grant access to review and approve mapping of a business service?
Answer: SM_App_Owner

I really appreciate it. Happy to send you a Starbucks card for your time. 🙂

tim_sewell · ‎07-26-2018

Yup, those make sense to me.

If they can't answer #1, they have absolutely no Service Mapping experience.

If they can't answer #2, they don't have much experience with Discovery and Mapping terminology. Doesn't mean they don't have experience with developing, but it's a fairly high level piece of information they missed..

I didn't know #3 off the top of my head, that map ownership and approval process is relatively new, I believe.

Another good one.. Service Mapping uses a set of steps to identify, discover information, and create relationships between each piece of infrastructure on a service map. What are these set of steps called?

A: Pattern

If they can't answer this one, they've never developed in Service Mapping.

Alicia13 · ‎07-26-2018

THANK YOU SO MUCH!!!!!

Would you possibly send me your email address or mailing address? I was serious about the Starbucks card.

Alicia13 · ‎07-26-2018

Hi Tim, also.. I just got approval from my Manager to pay a $2,000 referral bonus if you happen to know of anyone? There are two positions available.

Thank you again!

Alicia Loerzel

https://www.linkedin.com/in/alicialoerzel/

Ian Mildon · ‎07-26-2018

This should be as simple (now) of going to MID Server Applications and for ServiceMapping, setting the "Included in application ALL" to false. Then clicking into ServiceMapping and setting a Default MID Server.

While there you can add any additional ones to the related list so if the default is not available, it will only switch to a predefined MID Server.