---
sourceDocument: Yokohama IT Operations Management
sourceDocumentLink: https://servicenow-prod.fluidtopics.net/r/yokohama/it-operations-management

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    - yokohama

ft:locale :

    - en-US

ft:publication_title :

    - Yokohama IT Operations Management

ft:clusterId :

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bundleId :

    - itom

workflow :

    - Technology


---

# Enhance patterns without modifying identification sections

# Enhance patterns without modifying identification sections {#ariaid-title1}

* Release version: Yokohama
* 
* Updated January 30, 2025
* 
* ![](https://www.servicenow.com/docs/portal-asset/ico-clock) 3 minutes to read

Enable patterns to search for additional attributes and modify pattern discovery
logic defined in identification sections by using extension sections. Each extension section
contains a preconfigured set of discovery steps referred to as a shared library.

## Before you begin

If your ServiceNow instance uses domain separation and you have access to the global domain, log in to the relevant domain. The selected domain must be a domain without any child domains.

Basic knowledge of programming is desirable.

Role required: pd_admin

## About this task

Patterns can be of the infrastructure or application type. Infrastructure patterns are used only by Discovery for creating lists of devices. Application patterns serve both Service Mapping and Discovery, which use the same application patterns for their purposes.
Each pattern including its identification and connection sections is an individual
file. There are also reusable sequences of discovery steps referred to as shared
libraries. Each shared library is an individual file, but it is always part of the
infrastructure or application pattern and is not used as a standalone pattern.
Records for both patterns and shared libraries reside in the Discovery Patterns
\[sa_pattern\] table.

To modify the discovery logic in identification sections without changing the
identification sections themselves, you can add extension sections to the pattern.
Every extension section consists of a shared library, either new or existing.
Figure 1. Adding an extension section to a pattern   

When you create or modify a shared library in the extension section, you save changes only to the shared library, not to the pattern containing this extension section.  
Warning:  
The changes to the shared library affect all patterns using this shared library.

The MID Server runs extension
sections after identification sections and only if at least one identification
section completes successfully.

If there are more than one extension sections associated with this pattern, define
the order in which the MID Server runs these extension sections.  
You can deactivate shared libraries, so that patterns using them, skip steps in deactivated shared libraries. For more information, see [Discovery Configuration Console](https://servicenow-prod.fluidtopics.net/X2pEFslt2KYIkLpE0_rr8g#c_DiscoveryConfigurationConsole "Use the Discovery Configuration Console to manage what kind of configuration items (CIs) and CI information you want to discover."). If a precondition defined for a shared library step is not fulfilled, the pattern skips all steps belonging to this shared library. For example, if the file, to which the variable points, does not contain "test", the pattern does not run the shared library steps 1-1 to 1-5. The precondition exists only for the pattern within which you created it. The precondition does not affect other patterns using this shared library. Figure 2. Library Reference operation form   

## Procedure

1. Navigate to AllPattern DesignerDiscovery Patterns and open the required pattern from the pattern list.  
   The pattern can be of the Infrastructure or Application type.
2. To create an extension section and define discovery steps for its shared library.
   1. Click New under Extension section.
   2. Enter the name of this extension section.
   3. Click Done.  
      The pattern form displays the new section under Extension section.
   4. Click the name of the new extension section.  
      The Pattern Designer opens showing the Steps tree on the left.

      If no discovery steps have been identified for this pattern, the
      Untitled Step appears in the Steps tree
      in the left pane of the window.
   5. Define discovery steps.
   6. Click Save to save the extension section and make Service Mapping and Discovery use it.  
      You do not publish extension sections.
   {#modify-pattern-using-extensions__substeps_wj3_3h5_1bb}
3. To use an existing shared library for the new extension section:
   1. Click Add under Extension section.
   2. Select the shared library from the name list.
   {#modify-pattern-using-extensions__substeps_jd2_jh5_1bb}
4. If there are more than one extension sections, define the order in which the MID Server runs the extension section.
   1. Select the check box next to the extension section.
   2. Click Edit under Extension section.
   3. Enter a number that determines the order in the Order field.  
      If there is only one extension section, its order is 1 by default.

      The section with the lowest
      order number is used first.
   4. Click Done.
   {#modify-pattern-using-extensions__substeps_x45_csx_rbb}

## What to do next

Click Debug to run the newly created extension section. Pattern Designer runs extension sections after running identification sections.
**Previous topic:** [Discover related items together with the main CI](https://servicenow-prod.fluidtopics.net/P7~pCne5ETsQymLENF70iw "Add related items to the patterns to perform horizontal discovery of configuration items with all their related items: CIs or non-CIs, like ports or serial numbers.")  
**Next topic:** [Fine-tune patterns using traffic-based discovery](https://servicenow-prod.fluidtopics.net/UkfXq4ukdyThEwNF7wIkQg "As an alternative to customizing the pattern from the Pattern Designer side, improve existing patterns so that Service Mapping can use them to find configuration item (CI) connections previously found using traffic-based discovery.")

*[\>]: and then