My client has a lot of old CIs which shows the "most recent discovery" in 2017 and the discovery source is "Service-now". When I runs discovery in service mapping, it complains the unknown discovery source. I found the source "Service-now" is not in the discovery source drop down list in cmdb_ci table. So I created option "Service-now" in sys_choice for cmdb_ci table and element discovery_source. And I also created a reconciliation definition for load balancer Big5 IP and gave it order 10000. The top-down discovery runs successfully after this. I suspect even the reconciliation definition is not needed because that is for load balancer Big5 IP class but I noticed a CI in "load balance service" class had been updated by ServiceNow and changed its data source from Service-now to ServiceWatch .
I want to confirm if this is a necessary step to create the unknown discovery source "Service-now" in the sys_choice. From above experience, it seems to be necessary. But , I heard from another discovery SME, ServiceNow should update the CI with unknown discovery source. I need a firm answer from someone who experienced this before.
