De duplication task is not creaed for same serial number

[testtenentt]

Hi Everyone,

I am currently facing an issue with CMDB duplicate detection for the cmdb_ci_computer table and would appreciate your guidance.

• Identification Rule is configured as follows:

  • Priority 1 → serial_number

  • Priority 2 → name

• Two CIs exist with the same serial number

• Both belong to the same CI class: cmdb_ci_computer

Duplicate Metric Configuration:

• Active = true

• Create Task = true

• Correctness Score Calculation job is running daily

Observation:

For some serial numbers, duplicate remediation tasks are created successfully.

However, for other serial numbers, even though two CIs exist with the same serial number, no duplicate task is created.

I would like to understand:

• Is duplicate task creation dependent on specific CI attributes such as install status or lifecycle state?

• Is there any other functionality or configuration that controls the creation of duplicate remediation tasks?

• Are there any additional checks performed by CMDB Health before generating duplicate tasks?

Could someone please help clarify this behavior?

Thank you in advance for your support.

[fknell]

Hi @testtenentt,

This most probably is the explanation why no de-dub-tasks are created. Decommissioned CIs with the same serial_number may not trigger tasks, even if duplicate_of is empty, because the Duplicate Metric focuses on operational records.  

Identification Simulation: Testing IRE Rules and Creating Mock Data Here you find an easy guide to simulate creating another CI with identical data via IRE to verify if it will be identified as duplicate.  

Hope this helps!

[dimitrios_l]

If the 2 CIs have a discovery source populated they will not be flagged as duplicates. CMDB Fundamentals - How are duplicates determined. Not sure if that's your case. If so run a quick discovery for them to go through IRE again

[desaiakash0]

Hi  @testtenentt 

Duplicate remediation task creation in CMDB Health is not triggered solely by the presence of two CIs with the same identifier. Several additional checks and configurations determine whether a duplicate task will be created.

Based on your setup, please review the following areas:

1. CI Attribute Conditions (Install Status / Lifecycle / Operational Status)
   Duplicate CI metric evaluation depends on the metric condition. In many instances, only CIs with specific install status values (for example, Installed or In Use) are included.

If one CI is Retired, Absent, or Decommissioned, the system may not consider it during duplicate evaluation.

Please verify:

• Install Status
• Operational Status
• Lifecycle Stage
• Domain (if domain separation is enabled)

1. Duplicate CI Metric Configuration

Navigate to:
CMDB Health → Administration → Metrics
Open the Duplicate CI metric and verify:

• Active = true
• Create Task = true
• Applies to = cmdb_ci_computer
• Review the Condition field carefully

If a condition such as install_status = Installed exists, only those records will be evaluated.

1. Existing Open Remediation Task

The system will not create a new duplicate remediation task if an open task already exists for the same CI pair.

You can verify this in:
CMDB Health → Remediation Tasks
or
cmdb_health_remediation_task.list

1. Correctness Score Job Execution

Ensure the “Correctness Score Calculation” scheduled job is running successfully.

You can manually execute it from:
System Definition → Scheduled Jobs
Search for “Correctness Score Calculation” and click Execute Now.

Then recheck duplicate results.

1. Duplicate Detection Scope

Duplicate detection also verifies:

• CI must meet the metric condition
• CI must be within class scope
• No exclusion rules applied
• Identification attributes must match exactly (watch for trailing spaces or formatting differences in serial numbers)

Even small variations (extra spaces, case differences, hidden characters) can prevent detection.

Hope this helps for your further investigation!