Discovery via Probes does not mark "Duplicate of" field, and does not create de-duplicate task

[srikanthnelapud]

DESCRIPTION

When Discovery is triggered and flow routes through the Probes, instead of Patterns, then it triggered the identification probes like "Windows - Identify", "Linux - Identify", etc. Respective sensors leverage the API - IRE.Identify, provided by the Identification and Reconciliation Engine (IRE), that handles the deduplication and updates the "Duplicate of" field of a CI when there exist duplicates in the system.

In New York, IRE has updated its API that is being used by Discovery and as a part of fixing, it no longer handles the de-duplication and updates the "Duplicate of" field. Instead, a different API function - the IRE.createOrUpdate API changes the duplicate_of field on the duplicated CI, and it also creates de-duplicate task if at all the sys_id is not appended in the payload that will be passed to the IRE API.

For the post-New York release, you can check the below doc for details:
https://docs.servicenow.com/bundle/orlando-servicenow-platform/page/product/configuration-management/concept/id-detect-dup-ci.html
"That oldest duplicate CI also becomes the master CI for that set of duplicate CIs. The rest of the duplicate CIs are tagged as duplicates by setting the cmdb_ci's duplicate_of to the appropriate master CI. "

Related PRB: PRB1414887

Related Cases: CS4793662, CS4823757, CS4864051, CS4857273, CS4886575

Please note the below workaround is applicable for the users whose Discovery flow is running on Probes but not on Patterns.

WORKAROUND

Files to be modified:

• DiscoveryIDSensor (sys_script_include_3ee7cdf0c0a801645b4b4d71a122210f)
• DiscoveryJSONIDSensor (sys_script_include_88aed2069f71210054679ff3367fcf32)

Please note, both of the above files look completely the same so whatever changes which will be mentioned below, are applicable for both scripts.

Steps to modify:

STEP-1: Refer to the screenshot - CODE-CHANGE-1 and remove the complete highlighted portion in the"CMDBIdentify" function of both scripts.

STEP-2: Refer to the screenshot - CODE-CHANGE-2 and update the lines - 522 & 527 in the "processHostName" function of both scripts.

STEP-3: Refer to the screenshot - CODE-CHANGE-3 and update the lines - 605 & 615 in the "processIPAddressField" function of both scripts.

NOTE: Step-1 should suffice but Step-2 and Step-3 should also be done in order to handle the flipping of Name and IP Address, during the Discovery flow and these are the CI Identifiers out of the box.

For More Information regarding how the deduplication works, please refer to - Duplicate Configuration Items in the ServiceNow CMDB