Ask the Expert: Setting up the CMDB Health metrics and applying them to a real world CMDB

[Lisa Latour]

Join us on this discussion page for a YouTube Live Presentation on setting up CMDB health metrics and how to apply them.

It's an opportunity to see how the new CMDB Health Dashboard can help you manage the data quality of server and network device data. This new dashboard provides an actionable view of CI health and a remediation framework to take corrective actions.  

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Featured Expert

Presented by Richard Brounstein, ServiceNow Solution Architect for ITOM, specializing in IT Operations and crafting CMDB solutions for customers, based in the New York City area. He will be hosting a CMDB lab at Knowledge 2017. Before joining ServiceNow, Richard has more than 10 years experience as a System Engineer with Hewlett-Packard.

Watch the Demo Below and Read the Q&A below!
(Be sure to change your YouTube Setting to 720HD)

[richardbrounste]

Did you rerun the CMDB Health Dashboard Correctness Score Calculation

Configuration -> Health Properties

Scheduled Jobs (tab on right hand side)

Click into CMDB Health Dashboard Correctness Score Calculation job and click "Execute Now"

Then, go into the cmdb_health_metric_status table and make sure that the status of the jobs is complete. This can take time as it will scan all the cmdb_ci table

Then, clear your browser cache

Then, look at the CMDB Health Dashboard View and see if the duplicate count is the same.

[soren_dittmer]

Yep, did all that.

From the CI Class Manager, I traverse down the hierarchy to the AIX Server class and mark it. Click "Advanced", mark CI Identifiers.

There was the Hardware rule, which applies to the Hardware class ad all specializations.

Created a new rule, AIX Server Duplication rule which applies to the AIX Server class. this rule has only a single identifier entry, namely the ID (asset_tag).

Activated AIX Server Duplication rule and deactivated Hardware rule on the AIX Server class.

Then recalculated...

Execute Now.

cmdb_health_metric_status.list - wait until all jobs have completed

Clear cache

Same duplicate count.

[richardbrounste]

You look at the specific CI's and determine if the count really is incorrect. Click into the graph and you'll get a list of all the CI's. If it's not too many you should be able to really verify this. If it is too many then you can write a script to confirm this.

Sent from my iPhone

[soren_dittmer]

The count should be zero, but it is 123.

The IDs (asset_tags) are all unique, but there are 3-11 IDs with each of the 8 serial numbers. This is because there are 8 physical machines each hosting a number of logical partitions (LPARs) which are almost (but not entirely) as virtual machines.

I'm attempting to eliminate the serial number from the identification.

[richardbrounste]

Hi Soren:

I talked to R&D about this issue.   Duplicates are detected for the CMDB Health Dashboard during discovery.   Discovery will mark the field "discovery_source" as "duplicate" when duplicates are found.   It also creates De-Duplication tasks and the CIs appear on the Dashboard.

If you want the CMDB health Dashboard to scan for duplicates leveraging different CI Identification rules without doing Discovery, then you need to clear out the "discovery_source" field for those CIs and then have it rescan by running the Health Preferences Correction Rule.   The Health Preferences Correction Rule only scans CIs that are marked as duplicate from Discovery or CIs where the discovery_source is blank.

By the way, you can't eliminate the serial number from identification unless you eliminate it from the superclass hardware rule.   You can always add new rules that run as a higher priority for subclasses.

Richard Brounstein