Relationship Parent-Child and others

[ChasingSleep]

Hello guys,

We are defining the relationships for our CMDB, and I am a little confused by the difference between the parent-child relationship and the others...

For example, what is the difference between a “parent-child relationship” and a “contains relationship”? Aren't they the same thing? Why would I need to identify the "parent" of a "child" if I already know "who contains" or who "is contained"?

Regards

[UKVIKING]

let see

My maternal grandfather slept with my maternal grandmother
My mother was born
My maternal grandfather slept again with my maternal grandmother
my uncle (mother's brother) was born

My aternal grandfather slept with py maternal grandmother
My father was born
My paternal grandfather slept again with my paternal grandmother
my uncle (mother's brother) was born

my father slept with my mother
here I am

My mother is my parent. I am her child

That is parent child relationship

hopefully this helps.... but I doubt it
_________________
John Hardesty
ITSM Manager's Certificate (Red Badge)

Change Management is POWER & CONTROL. /....evil laughter

[UKVIKING]

Seriously now

You are talking about data base relationships - at the lowest level and CI Relationship at the highest level

1 - how have your org defined the relationships that are used to describe how 1 CI relates to another
2 - have you made sure that the CMDB database tool reflects that ?

You can define the CI relationship many ways

dependent - the CI is dependent on another CI for something - network, applicaiton, etc
peer - the CI is a peer to another CI in which they serve the same function
independent - the CI does not have to depend on any other CI
shared - the CI is used (depended upon) by one or more CIs

Now - how can this be contrived

It depends

an egress router connects to the public internet
an firewall connects to the egress router
an internal router connects to the firewall
multiple switches supporting differnent internal LANs, VLANs etc connects to the internal router

There is an application server that connects to a switch
the app server connects to a security / access server (LDAP) or AD server
The app server connects to cluster of DB servers
the app server also connects to a web server, mail server

how do you define the relationships

at the network layer ?
at the Application layer ?
awhere ?

the answer is it depends on what you want from the cmdb
_________________
John Hardesty
ITSM Manager's Certificate (Red Badge)

Change Management is POWER & CONTROL. /....evil laughter

[ChasingSleep]

UKVIKING,

First of all, thanks for your help!

I understand all the relationships you mentioned (dependent, peer, shared..). My doubt is because I read that a parent-child relationship is used a lot with basic inventories, just to give a view of the hierarchic tree of assets.

So, I understood that this relationship refers to who is up in the tree (parent) and who is down (child). But then the question: Why is it important to have such a relationship? Is it just to help visualize the tree of assets?

Thanks

[UKVIKING]

CI Relationships help in the following ways

Determine impact of incidents - minor and otherwise and help determine urgency
determine risk & impact of changes / release

For example

There is an incident for a web server. The server crashes with the BSD (WinTel). The ticket initially is raised as a High priority (scale 1 to 5 ) Priority 1. The SD team lead checks the CMDB and finds that this web servers is in a farm of 5 web servers (peers) - and the web site is unaffected. The four remaining will just work and load share / balance w/o the fifth
The SD T/L lowers the priority to 2 or 3 and the urgency to 2 or 3 - as there is NO real impact

The system team can deal with this server at its respective leisure (real P1s take precedence.

There is an incident for a LAN switch. The Monitoring tool - managing only net gear - notes that the switch is down. This gets raised at a normal level for the equipment type. Further investigation by the SD finds that several application servers are solely linked via this switch (Single point of failure). The application users are developers and the applications only support the developers. The SD T/L checks with the owner of the applications and finds out that the developers are between projects and the environment is not used. The ticket can remain at a normal priority

There is a router outage. The router has a peer. However, the 2 routers are egress routers to the internet. The remaining router will get hammered and all internet connections will suffer some degradation
A further check of the CMDB indicates which areas of business is using that pair of egress routers. The priority / urgency should be higher and the SD T/L can inform the owners / users of the environments about the internet connectivity issues.

just a sample

F
_________________
John Hardesty
ITSM Manager's Certificate (Red Badge)

Change Management is POWER & CONTROL. /....evil laughter

[ChasingSleep]

Yeah, but all these examples could be done with relationships like peer, connected, dependent, share...

I can't figure out an example for why a parent-child relationship would be useful...

[UKVIKING]

Parent child is the dependent / depended upon
_________________
John Hardesty
ITSM Manager's Certificate (Red Badge)

Change Management is POWER & CONTROL. /....evil laughter

[ChasingSleep]

Ok, so it has nothing to do with the asset type position in the hierarchic tree of assets...

I guess then we can just forget this parent-child thing and use dependent / depended upon, which is much easier to quickly visualize what it implies...

Thanks again!

[UKVIKING]

CS

Another way to track CIs is this way

Std User Laptop - MS Office - Standard (Word, excel, outlook, powerpoint)
power User - Std laptop + Visio, Project and Access

The STD laptop should be used for all well standard builds

the power user laptop would be a variant of that std laptop

this would be helpful to IT helpdesk managing PCs, laptops etc
_________________
John Hardesty
ITSM Manager's Certificate (Red Badge)

Change Management is POWER & CONTROL. /....evil laughter

[ChasingSleep]

That's interesting.

We have here three different images (A, B and C). Each and every desktop has on of these images installed. Some desktops have also specific software installed on top of their image (e.g. Visio).

So we could have the following CIs:

Desktop
Image A
Image B
Image C
Visio

And the following relationships:

Image A «=contains=» Windows XP, MS-Office
Image B «=contains=» Windows XP, MS-Office, Development tools
Image C «=contains=» Windows XP, MS-Office, Financial tools
Desktop 123 «=runs=» Image A
Desktop 456 «=runs=» Image B and «=runs=» Visio

And the images (and specific software like Visio) also have relationships to their licenses and media, all stored in the DSL.

It starts to make sense! Finally!

Thanks

[UKVIKING]

CS

Desktop456 is a variant of Image B - because of Visio
_________________
John Hardesty
ITSM Manager's Certificate (Red Badge)

Change Management is POWER & CONTROL. /....evil laughter

[Ed]

[UKVIKING]

Welll.... actually

it is the theory of relativity....

Unless I am mistaken that is how it is written in the geneology tables

whether sleep was involved or merely .... is another story

I wont go there
_________________
John Hardesty
ITSM Manager's Certificate (Red Badge)

Change Management is POWER & CONTROL. /....evil laughter

[Ed]

Sorry I thought it was a little more obvious


I was more interested in the who and the results!!!!
_________________
Regards

Ed

[UKVIKING]

Why

did you know my paternal grandparents ?

My maternal grandmother is still alive at 100 - coming soon in april to 101
_________________
John Hardesty
ITSM Manager's Certificate (Red Badge)

Change Management is POWER & CONTROL. /....evil laughter