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ChasingSleep Senior Itiler

Joined: Nov 18, 2008 Posts: 78
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Posted: Sat Jan 17, 2009 7:03 am Post subject: Relationship Parent-Child and others |
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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"?
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UKVIKING Senior Itiler

Joined: Sep 16, 2006 Posts: 3590 Location: London, UK
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Posted: Sun Jan 18, 2009 12:24 am Post subject: |
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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 |
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UKVIKING Senior Itiler

Joined: Sep 16, 2006 Posts: 3590 Location: London, UK
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Posted: Sun Jan 18, 2009 12:36 am Post subject: |
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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 |
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ChasingSleep Senior Itiler

Joined: Nov 18, 2008 Posts: 78
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Posted: Tue Jan 20, 2009 12:25 am Post subject: |
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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?
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UKVIKING Senior Itiler

Joined: Sep 16, 2006 Posts: 3590 Location: London, UK
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Posted: Tue Jan 20, 2009 1:02 am Post subject: |
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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 |
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ChasingSleep Senior Itiler

Joined: Nov 18, 2008 Posts: 78
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Posted: Tue Jan 20, 2009 4:27 am Post subject: |
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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... |
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UKVIKING Senior Itiler

Joined: Sep 16, 2006 Posts: 3590 Location: London, UK
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Posted: Tue Jan 20, 2009 5:36 am Post subject: |
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Parent child is the dependent / depended upon _________________ John Hardesty
ITSM Manager's Certificate (Red Badge)
Change Management is POWER & CONTROL. /....evil laughter |
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ChasingSleep Senior Itiler

Joined: Nov 18, 2008 Posts: 78
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Posted: Tue Jan 20, 2009 6:02 am Post subject: |
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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! |
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UKVIKING Senior Itiler

Joined: Sep 16, 2006 Posts: 3590 Location: London, UK
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Posted: Tue Jan 20, 2009 6:56 pm Post subject: |
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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 |
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ChasingSleep Senior Itiler

Joined: Nov 18, 2008 Posts: 78
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Posted: Wed Jan 21, 2009 1:04 am Post subject: |
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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!
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UKVIKING Senior Itiler

Joined: Sep 16, 2006 Posts: 3590 Location: London, UK
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Posted: Wed Jan 21, 2009 3:18 am Post subject: |
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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 |
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Ed Senior Itiler

Joined: Feb 28, 2006 Posts: 411 Location: Coventry, England
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Posted: Wed Jan 21, 2009 9:50 pm Post subject: |
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UKVIKING wrote: | 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
Is this true????  _________________ Regards
Ed |
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UKVIKING Senior Itiler

Joined: Sep 16, 2006 Posts: 3590 Location: London, UK
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Posted: Wed Jan 21, 2009 10:48 pm Post subject: |
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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 |
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Ed Senior Itiler

Joined: Feb 28, 2006 Posts: 411 Location: Coventry, England
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Posted: Wed Jan 21, 2009 11:45 pm Post subject: |
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Sorry I thought it was a little more obvious
I was more interested in the who and the results!!!!  _________________ Regards
Ed |
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UKVIKING Senior Itiler

Joined: Sep 16, 2006 Posts: 3590 Location: London, UK
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Posted: Thu Jan 22, 2009 12:53 am Post subject: |
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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 |
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