--- title: "50,000 Unresolved Duplicate Tasks: An IRE Rule With No Fallback" description: More than 50,000 duplicate tasks sat unworked because one identification rule had no fallback. How we found the cause and cleared the backlog. image: https://www.apexconfiguration.com/hubfs/AI-Generated%20Media/Images/Bright%20Modern%20Open%20Plan%20IT%20Office.png --- [![APEX CONFIGURATION GROUP](https://www.apexconfiguration.com/hs-fs/hubfs/Act3%20child/images/ACG-logo.png?width=135&height=93&name=ACG-logo.png "APEX CONFIGURATION GROUP")](https://www.apexconfiguration.com/) [![APEX CONFIGURATION GROUP](https://www.apexconfiguration.com/hs-fs/hubfs/Act3%20child/images/ACG-logo.png?width=135&height=93&name=ACG-logo.png "APEX CONFIGURATION GROUP")](https://www.apexconfiguration.com/) - [Home](https://www.apexconfiguration.com) - ServiceNow - [ServiceNow CMDB](https://www.apexconfiguration.com/servicenow-cmdb) - [CMDB Health Check](https://www.apexconfiguration.com/cmdb-health-check) - [CMDB Design & Implementation](https://www.apexconfiguration.com/cmdb-design-implementation) - [Managed Service](https://www.apexconfiguration.com/managed-cmdb-services) - [Automation & Optimisation](https://www.apexconfiguration.com/cmdb-automation-tools) - Maximising ServiceNow - [CMDB Health Dashboard](https://www.apexconfiguration.com/cmdb-health-dashboard-servicenow) - [CMDB Dependency Mapping](https://www.apexconfiguration.com/cmdb-relationship-table) - [CMDB Configuration Items](https://www.apexconfiguration.com/cmdb-configuration-items) - [CMDB Workspace](https://www.apexconfiguration.com/cmdb-workspace-servicenow) - [CMDB Best Practice](https://www.apexconfiguration.com/cmdb-best-practices) - [ServiceNow Discovery](https://www.apexconfiguration.com/servicenow-discovery-setup) - [Service Mapping](https://www.apexconfiguration.com/servicenow-service-mapping) - About - [How We Help](https://www.apexconfiguration.com/about-apex) - [What is a CMDB?](https://www.apexconfiguration.com/what-is-cmdb) - [Benefits](https://www.apexconfiguration.com/benefits-of-cmdb) - Resources - [Blog](https://www.apexconfiguration.com/blog) - [Contact Us](https://www.apexconfiguration.com/contact-us) [Contact Us](https://www.apexconfiguration.com/contact-us) [Contact Us](https://www.apexconfiguration.com/contact-us) - [Home](https://www.apexconfiguration.com) - ServiceNow - [ServiceNow CMDB](https://www.apexconfiguration.com/servicenow-cmdb) - [CMDB Health Check](https://www.apexconfiguration.com/cmdb-health-check) - [CMDB Design & Implementation](https://www.apexconfiguration.com/cmdb-design-implementation) - [Managed Service](https://www.apexconfiguration.com/managed-cmdb-services) - [Automation & Optimisation](https://www.apexconfiguration.com/cmdb-automation-tools) - Maximising ServiceNow - [CMDB Health Dashboard](https://www.apexconfiguration.com/cmdb-health-dashboard-servicenow) - [CMDB Dependency Mapping](https://www.apexconfiguration.com/cmdb-relationship-table) - [CMDB Configuration Items](https://www.apexconfiguration.com/cmdb-configuration-items) - [CMDB Workspace](https://www.apexconfiguration.com/cmdb-workspace-servicenow) - [CMDB Best Practice](https://www.apexconfiguration.com/cmdb-best-practices) - [ServiceNow Discovery](https://www.apexconfiguration.com/servicenow-discovery-setup) - [Service Mapping](https://www.apexconfiguration.com/servicenow-service-mapping) - About - [How We Help](https://www.apexconfiguration.com/about-apex) - [What is a CMDB?](https://www.apexconfiguration.com/what-is-cmdb) - [Benefits](https://www.apexconfiguration.com/benefits-of-cmdb) - Resources - [Blog](https://www.apexconfiguration.com/blog) - [Contact Us](https://www.apexconfiguration.com/contact-us) [Contact Us](https://www.apexconfiguration.com/contact-us) [tel:+442080588135](tel:+442080588135)[mailto:contact@apexconfiguration.com](mailto:contact@apexconfiguration.com) [Case Studies](https://www.apexconfiguration.com/blog/tag/case-studies)[IRE](https://www.apexconfiguration.com/blog/tag/ire) [ServiceNow](https://www.apexconfiguration.com/blog/tag/servicenow)[Duplicate CIs](https://www.apexconfiguration.com/blog/tag/duplicate-cis) # 50,000 Unresolved Duplicate Tasks: An IRE Rule With No Fallback [![Paulina Nadera](https://www.apexconfiguration.com/hs-fs/hubfs/paulina-nadera.webp?width=40&height=40&name=paulina-nadera.webp)](https://www.apexconfiguration.com/blog/author/paulina-nadera) by [Paulina Nadera](https://www.apexconfiguration.com/blog/author/paulina-nadera) 3 min read Oct 2, 2026, 9:00:01 AM A client believed its Identification and Reconciliation Engine (IRE) was preventing duplicate configuration items (CIs). When Apex was engaged, we noticed more than 50,000 de-duplication tasks that had never been addressed. The cause sat in the identification rules, where an entry required two attributes to match and had no fallback for a source that supplied only one of them. Two Apex analysts spent eight weeks resolving the backlog, and an Apex architect fixed the rules. | At a glance | | | --- | --- | | Sector | Consulting | | Estate | Millions of CIs | | What went wrong | Existing scans created duplicate CIs because of the identification and reconciliation rules | | What it cost | Eight weeks of two analysts resolving de-duplication tasks | | What fixed it | Two Apex analysts clearing the backlog and an Apex architect correcting the IRE | ## What the client believed the engine was doing The belief was reasonable. The engine was in place, the rules had been written, and scans were running. Anyone reading [our guide to the configuration management database](https://www.apexconfiguration.com/what-is-cmdb) would expect the engine to be doing exactly that job. In this estate it was not, and the existing scans were the ones creating the duplicates. ## How one machine became two CIs The fault sat in one kind of rule. An identification entry can require several attributes to match at once. In this estate an entry required both a serial number and a media access control address. Take a server with serial number SN-98765 and media access control address 00:1A:2B:3C:4D:5E. The first source sends both values, the entry matches nothing existing, and the engine creates CI-001. That is correct. A second source then reports the same server, but supplies only some of the values, say the serial number without the media access control address. The entry requires both. There is no fallback entry that matches on the serial number alone, so the engine cannot link the record to CI-001 and creates CI-002. One machine, two CIs. Repeat that across an estate of millions of CIs, and every source that reports a different set of attributes can add to the pile. The engine raised de-duplication tasks for the overlaps it could see, and nobody worked them. ## What we found when we were engaged When the client engaged Apex, we noticed more than 50,000 open de-duplication tasks. None of them had ever been addressed. A backlog of that size measures how long a rule has been wrong. A task list that only ever grows tells you the identification rules are producing duplicates faster than anyone can resolve them. ## Eight weeks, two analysts and one architect Two Apex analysts resolved the de-duplication tasks over eight weeks, and an Apex architect corrected the IRE. The architect's work mattered as much as the analysts'. A backlog refills while the rule that creates it is still wrong, so clearing tasks without fixing the entry would have been eight weeks of treading water. Fixing the [identification rules](https://www.apexconfiguration.com/blog/servicenow-identification-rules-how-cmdb-duplicate-prevention-really-works) comes first. Only then does it make sense to look at which source is allowed to write which attribute, which our article on [reconciliation rules](https://www.apexconfiguration.com/blog/servicenow-reconciliation-rules-which-source-wins) covers. ## Checks that would have found this early 1. **Report open de-duplication tasks by age and class every week.** A backlog that ages is a rule problem waiting for someone to look. 2. **List what each identification entry requires and which sources supply it.** Any entry that requires two attributes needs a fallback entry for a source that provides only one. 3. **Test each source with a sample record against the rules.** Watch whether it updates an existing CI or creates a new one. 4. **Look at reconciliation precedence only after identification is sound.** Otherwise the reconciliation rules end up protecting duplicates instead of removing them. ## How Apex helps Our data quality assessment scores your estate against weighted critical success factors, key performance indicators (KPIs) and metrics. It identifies where de-duplication, normalisation and reconciliation are failing, and why. It is scoped at an initial consultation against your requirements and your estate. For a quick, scored view, our two-week CMDB health baseline tells you which CIs are trustworthy and which are guesses, in a report you can take to your change advisory board. [Book a CMDB diagnostic call](https://www.apexconfiguration.com/cmdb-diagnostic-call) or [arrange a meeting with one of our consultants](https://www.apexconfiguration.com/book-a-meeting). ## Frequently asked questions ### Is a large de-duplication backlog always a rule problem? Not always, but a backlog that keeps refilling points to a rule or a source that is creating the duplicates. Find what the new tasks have in common before you decide how to clear them. ### Should we clear the backlog before fixing the rules? Fix the rule that creates the tasks first, or work on both together. Clearing tasks while the rule is still wrong means the backlog grows back. ### Why would an identification entry that requires two attributes cause duplicates? A record that supplies only one of the two cannot match the entry. Without a fallback entry that matches on the single attribute, the engine creates a new CI instead of updating the existing one. - Recent - Topics - Archive Recent ### Recent Topics ### Topics - [ServiceNow (28)](https://www.apexconfiguration.com/blog/tag/servicenow) - [CMDB (24)](https://www.apexconfiguration.com/blog/tag/cmdb) - [CMDB Data Quality (10)](https://www.apexconfiguration.com/blog/tag/cmdb-data-quality) - [Change Management (4)](https://www.apexconfiguration.com/blog/tag/change-management) - [Service Mapping (4)](https://www.apexconfiguration.com/blog/tag/service-mapping) - [Agentic AI (3)](https://www.apexconfiguration.com/blog/tag/agentic-ai) - [CI Ownership (3)](https://www.apexconfiguration.com/blog/tag/ci-ownership) - [Compliance & Audit (3)](https://www.apexconfiguration.com/blog/tag/compliance-audit) - [Data Model Design (3)](https://www.apexconfiguration.com/blog/tag/data-model-design) - [Duplicate CIs (3)](https://www.apexconfiguration.com/blog/tag/duplicate-cis) - [Incident Management (3)](https://www.apexconfiguration.com/blog/tag/incident-management) - [Vulnerability Management (3)](https://www.apexconfiguration.com/blog/tag/vulnerability-management) - [Case Studies (2)](https://www.apexconfiguration.com/blog/tag/case-studies) - [Cyber Security (2)](https://www.apexconfiguration.com/blog/tag/cyber-security) - [Dependency Views (2)](https://www.apexconfiguration.com/blog/tag/dependency-views) - [Enterprise Risk Management (2)](https://www.apexconfiguration.com/blog/tag/enterprise-risk-management) - [IT Cost Optimisation (2)](https://www.apexconfiguration.com/blog/tag/it-cost-optimisation) - [IT Governance (2)](https://www.apexconfiguration.com/blog/tag/it-governance) - [Problem Management (2)](https://www.apexconfiguration.com/blog/tag/problem-management) - [Service Graph Connectors (2)](https://www.apexconfiguration.com/blog/tag/service-graph-connectors) - [ServiceNow Discovery (2)](https://www.apexconfiguration.com/blog/tag/servicenow-discovery) - [CI Reconciliation (1)](https://www.apexconfiguration.com/blog/tag/ci-reconciliation) - [CMDB Remediation (1)](https://www.apexconfiguration.com/blog/tag/cmdb-remediation) - [CSDM (1)](https://www.apexconfiguration.com/blog/tag/csdm) - [Configuration Management (1)](https://www.apexconfiguration.com/blog/tag/configuration-management) - [IRE (1)](https://www.apexconfiguration.com/blog/tag/ire) - [IT Asset Management (1)](https://www.apexconfiguration.com/blog/tag/it-asset-management) - [Operational Efficiency (1)](https://www.apexconfiguration.com/blog/tag/operational-efficiency) - [ServiceNow Advisory (1)](https://www.apexconfiguration.com/blog/tag/servicenow-advisory) See all Archive ### Archive - [October 2026 (1)](https://www.apexconfiguration.com/blog/archive/2026/10) - [September 2026 (16)](https://www.apexconfiguration.com/blog/archive/2026/09) - [August 2026 (2)](https://www.apexconfiguration.com/blog/archive/2026/08) - [July 2026 (4)](https://www.apexconfiguration.com/blog/archive/2026/07) - [June 2026 (3)](https://www.apexconfiguration.com/blog/archive/2026/06) - [May 2026 (2)](https://www.apexconfiguration.com/blog/archive/2026/05) See all ### Subscribe by email Share this [Share on X](https://x.com/intent/post?url=https://www.apexconfiguration.com/blog/unresolved-duplicate-tasks-ire-fallback&text=50%2C000+Unresolved+Duplicate+Tasks%3A+An+IRE+Rule+With+No+Fallback) [Share on Facebook](https://www.facebook.com/sharer/sharer.php?u=https://www.apexconfiguration.com/blog/unresolved-duplicate-tasks-ire-fallback&t=50%2C000+Unresolved+Duplicate+Tasks%3A+An+IRE+Rule+With+No+Fallback) [Share on LinkedIn](https://www.linkedin.com/shareArticle?mini=true&url=https://www.apexconfiguration.com/blog/unresolved-duplicate-tasks-ire-fallback&t=50%2C000+Unresolved+Duplicate+Tasks%3A+An+IRE+Rule+With+No+Fallback) Previous story [← Recurring Incidents: Spotting Patterns Across Shared CIs](https://www.apexconfiguration.com/blog/recurring-incidents-shared-cis) ![Paulina Nadera](https://www.apexconfiguration.com/hs-fs/hubfs/paulina-nadera.webp?width=64&height=64&name=paulina-nadera.webp) By [Paulina Nadera](https://www.apexconfiguration.com/blog/author/paulina-nadera) Configuration Management Consultant at Apex Configuration Group, based in Wrocław, Poland. 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