question Defining the 'Depends On::Used By' relationship between an Application Service and Infrastructure CI in Common Service Data Model forum

Defining the 'Depends On::Used By' relationship between an Application Service and Infrastructure CI

PG2 — Tue, 15 Nov 2022 05:40:52 GMT

I'm hoping someone in the community can add some thoughts on the Depends on::Used by relationship type when used to describe a dependency between an Application Service and an Infrastructure CI (such as a server).

I'm determining whether the relationship represents a current and active dependency between the CIs or if it intends to reflect any historical reliance.

How do others use this relationship type? And how do you maintain the relationship based on different scenarios? (such as the one I've attached as an example)

Re: Defining the 'Depends On::Used By' relationship between an Application Service and Infrastructur

Barry Kant — Tue, 15 Nov 2022 06:39:54 GMT

Good day PG2,

CI relations are intended to be current state values. To my knowledge there isn't something that reflects historical states. If so then I would expect that in audits or notes.

BR,

Barry

Re: Defining the 'Depends On::Used By' relationship between an Application Service and Infrastructur

Jim Zeigler1 — Tue, 15 Nov 2022 16:59:02 GMT

Hi PG2,

If you are licensed for ITOM Service Mapping, one of the population methods for your Application Service should be used to maintain the dependency(stored as Service Configuration Item Associations) between the Application Service and the infrastructure CIs.

If you used a pattern based population method (Mapped Application Service), when the original version of the Application Service is retired, the Load Balancer VIP used as your entry point for the Application Service should have been removed from the LB or the LB service should be modified to no longer reference the infrastructure CI. There is a daily scan of Load Balancer Services that will catch the update to the LB service.

Re: Defining the 'Depends On::Used By' relationship between an Application Service and Infrastructur

PG2 — Wed, 16 Nov 2022 01:30:11 GMT

I agree and am attempting to formulate a definition that reflects the relationship types purpose. I have this so far, and I am sharing it in case it is helpful to others.

Depends On::Used By

Relationship type

Describes an operational dependency where a parent CI needs a child CI to function; (e.g. a change or incident on a child CI may impact the function of its parent).

Re: Defining the 'Depends On::Used By' relationship between an Application Service and Infrastructur

PG2 — Wed, 16 Nov 2022 01:37:50 GMT

Thank you for sharing. I'm unfamiliar with the service mapping population method, but I was searching for OOTB behaviour for the scenario where the Application Service is Retired.

If the OOTB pattern removes the entry point, that reinforces the purpose of the 'Depends on::Used by' relationship type. e.g. it reflects the current/operational dependency.

Most of our Application Services are populated using the manual method, and I've not found OOTB business rules that would remove relationships. There is also some conjecture across the community forums about the correct approach.

Re: Defining the 'Depends On::Used By' relationship between an Application Service and Infrastructur

Ed Laar — Fri, 18 Nov 2022 15:16:50 GMT

Hi,

First of all: The CMDB should represent the as-is situation of the infrastucture, it's components, services and so on. In this way the CMDB can (and should) be used to do incident impact and priorization, Change impact analysis in order to prevent from Service down situations after changes and so on.
History answering a question like 'What was the situation with this component a month ago' should be answered by the history list of the component (do not forget to enable this feature!).

CI-CI relations are used to create groups of elements/ CI's that provide together a certain functionality or service. Simple example: Dbase runs on::runs Server. As soon as one of the two CI's change their state or are removed also the CI-CI relation should be changed or removed, otherwise you will have CI-CI relations that do not relate any CI.

To maintain CI-CI relations Service Mapping is the way to go here. Adding rules or creating reports on 'incomplete CI-CI relations' can also be a possibility.

Re: Defining the 'Depends On::Used By' relationship between an Application Service and Infrastructur

JesperGuldfeldt — Mon, 29 Apr 2024 11:59:36 GMT

Hey PG2

Did you ever finish such a list, which defines the relationship types purpose 😊