Role of CMDB identifiers and CI Identifiers

[rajeevhanda]

There are two categories of identifiers:

1. CI Identifiers (ci_identifier)

2. CMDB Identifier (cmdb_identifier)

What is the difference between the two?

The CMDB Dashboard "Duplicate" metric relies upon the "cmdb_identifiers" table to specify the rules used to tag CIs as "duplicate" during the Correctness audit. But does Discovery use the same identifier to determine the uniqueness of CIs...to identify the CI and determine if it will update an existing CI or Create a new one?

[Sundar10]

Hello All,

I was also looking for answer for this question. Luckily after going through a doc in ServiceNOW, kind of found the answer.

Prior to Geneva Release, ServiceNOW Disovery uses CI Identifier which is a legacy identifier. However in Geneva and releases after that ServiceNOW introduced a new identifier concept CMDB Identifier, where we can define rules for Tables and Fields in the CI. Therefor discovery will use this identification rules, if the property is enabled in the instance. If not it will use the same old legacy identifier (CI Identifier) which likely to have issues while discovery CI's post upgrate from older versions to new versions.

Feel free to revert in case of any clarifications or discrepancies.

Hit the Like button and Mark this as solution if this helped you.

Regards,

Sundar

[mehak1890]

Hi Sundar/All,

I am also confused with the concept of CI identifer and CMDB Identifier. We have implemented discovery 4 years back with legacy identifiers. Now we are upgrading to London and we have many issues which revolves around identifer concept like 

1) we have servers which are getting discovered with alias names as well so we have multiple entries for same server. If we can modify the identifer for servers to use Serial number then we can resolve this issue however Legacy identifer is common for all hardware class so want to use CMDB identifer to update the same.

2) Applications are getting discovered again/duplicate whenever servers/applications are restarted. We can update the CI Identifier with Unique ID and we can resolve this issue.

It would be great if you can specify how to enable CMDB Identifer and how to validate if we can use both CI/CMDB identifer at a time.

Please help with the explanation.

Thanks in advance.

Mehak

[Sundar10]

Hello,

You have to create a property - glide.discovery.use_cmdb_identifiers (Type : true|false; Value : true). Once this created automatically legacy identifier will be disabled, and when you click on identifier it will re-route you to the CMDB identifier. 

Feel free to revert in case of any clarifications or discrepacies.

Regards,

Sundar

[mehak1890]

Thanks Sunder for your response, just want to know after adding this property do i need to do any special testing? or how it will impact for previous running discovery for cmdb data. I just want to take precautions in advance. Hope you will understand. Do i need to take any backup? Thanks, Mehak

[Sundar10]

Hello,

No need, it will use the CMDB identifier by default. Just run discovery for an existing and a new CI. Check which matching criteria is taken and modify the identifier as per the requirements if required. Let me know in case if any assitance is required.

Mark this response as Answer if this resolves your concern. 

Regards,

Sundar