When does IRE update the discovery_source field of a CI?

[Ash42]

The Identification and Reconciliation engine (IRE) documentation page, section: Timestamps in key attributes (https://docs.servicenow.com/bundle/rome-servicenow-platform/page/product/configuration-management/concept/ire.html) suggests that "IRE always updates CIs’ last_discovered and discovery_source attributes during payload processing, even when no other CI attributes are updated."
I've migrated to SG-SCCM 3.06 from MS-SCCM plugin recently and added a second SCCM server as a data source. I've noticed that not all CI's (Computers, Servers) have their Discovery Source field changed to SG-SCCM (from MS SMS or empty), even though SG-SCCM is updating these CI's. Only CI's that are inserted/created have the Discovery Source set to SG-SCCM.
Can anyone confirm this is the expected behavior?

[Anshu_Anand_]

Have you checked the precedence rule in IRE.

In CI class manager, check reconciliation rules.

Please set the reconcilation rule and change the priority of processing

Also your CI payload is passing through IRE engine as servicenow discovery do OOTB?

Hope this is helpful or let me know then.

[Ash42]

Anshu,

Thanks for suggesting the Reconciliation Rules. No reconciliation rules are setup on the CI Classes in question. I tried to add a rule for the Discovery Source attribute, but the field is not available for selection. SG-SCCM is our only data source. We don't have Discovery, ServiceMapping or other data sources.

SG-SCCM CI payload processing is OOTB. We have not done any customization here.

[Kianna]

Is there any more information on this? I am facing a similar issue where the discovery source field is not getting updated to SG-SCCM on CI's (computers,servers) even after SG-SCCM updates CI's.

[Ash42]

The following workaround worked for us.

"We have a property "glide.identification_engine.skip_updating_source_last_discovered_if_older"

Determines whether IRE updates the last_discovered and the discovery_source attributes in the CMDB.

true: If last_discovered is provided in the payload and it is older than the last_discovered of the CI in the CMDB, IRE does not use the payload values to update the last_discovered and the discovery_source attributes in the CMDB.

false: Even if the last_discovered provided in the payload is older than the last_discovered of the CI in the CMDB, IRE uses the payload values to update the last_discovered and the discovery_source attributes in the CMDB.
Type: true | false
Default: true

I would recommend you add the above property and set the value to false so the discovery source is updated always."