Not all CIs are checked by the Duplicate Metric, even if they "appear" to be duplicate.

When CMDB Health - Correctness job runs, the Duplicate Metric only checks CIs that have Identification Rule defined,

and also meet one of below conditions:

> one of the duplicated CIs has empty Discovery Source attribute

> there is an active de-duplicate task (reconcile_duplicate_task) for the duplicated CIs

To fix all the left-over CIs, please run discovery, or any custom scripts / import engine that calls IRE (Identification and Reconciliation Engine).

*** Note below Examples are out of date, and applies to instance release prior to New York.

In New York, we have introduced a new field: duplicate of.

However, the logic is very similar to below.

Bottom line is, if both CIs have Discovery Source value, then not detected, regardless of the value in duplicate of attribute.




There are two CIs, having same name and serial number, when duplicate metric runs, the result is based on discovery_source and reconcile_duplicate_task:

Case 1:

CI01 Discovery Source: ServiceNow
CI02 Discovery Source: ServiceNow

Result: not detected, unless there is a deduplicate task (reconcile_duplicate_task)

Case 2:

CI01 Discovery Source: ServiceNow
CI02 Discovery Source: Duplicate

Result: not detected, unless there is a deduplicate task (reconcile_duplicate_task)

Case 3:

CI01 Discovery Source: SomeSource (discovery source that doesn't exist in sys_choice table)
CI02 Discovery Source: Duplicate

Result: not detected, unless there is a deduplicate task (reconcile_duplicate_task)

Case 4:

CI01 Discovery Source: ServiceNow
CI02 Discovery Source: (empty)

Result: detected, empty changed to Duplicate, deduplicate task created

Case 5:

CI01 Discovery Source: (empty)
CI02 Discovery Source: (empty)

Result: detected, one changed to Duplicate, the other changed to Unknown, deduplicate task created

Additional Information

1. In order to find duplicates, Duplicate Processor calls Identification and Reconciliation Engine (IRE). It uses 'Manual Entry' as the data source in that IRE call.

If the out of box 'Manual Entry' option is deleted, when processing duplicate metric, the IRE will throw error:

identification_engine : INVALID_INPUT_DATA In payload invalid data source [Manual Entry] exist. You need to provide a valid choice value from field [discovery_source] in table [cmdb_ci].

Thus please make sure the out of the box Discovery Source 'Manual Entry' is not changed or deleted.

2. Please also refer to KB0712338 which explains the workflow of Duplicate Metric when health job runs.

Article Information

Last Updated:2020-09-02 20:51:16