When running Discovery on a server that hosts DB2 Instance, the Name field of the instance (cmdb_ci_db2_instance) is not updated or modified. Even though the discovery run completed without issue.
Below is the logic used during DB2 instance discovery.
During the IRE processing, DB2 instance uses 'DB2 Instance rule by ServiceWatch' reconciliation rule. This rule will block update on the DB2 Instance CI if the source is not ServiceWatch.
This is expected behavior
It is also mentioned in the documentation that DB2 Instance should be only discovered using Service Mapping (Top Down).
Some customers might only have Discovery plugin installed in their environment. Out of the box, DB2 on Windows Pattern is not triggered when running Horizontal Discovery.
If the customer want to use this pattern for Horizontal Discovery, Reconciliation rule 'DB2 Instance rule by ServiceWatch' needs to be disabled.