CI deletion strategies for pattern discovery

  • Release version: Yokohama
  • Updated July 20, 2026
  • 2 minutes to read
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    Summary of CI deletion strategies for pattern discovery

    When you use pattern-based Discovery in ServiceNow, you can control how to handle configuration items (CIs) in the CMDB that Discovery can no longer find. This feature applies only to pattern discovery, not to probes or sensors. Patterns identify a main CI type (e.g., IIS web server) and also discover related CIs (such as the host machine, configuration files, and hosted websites) to build a comprehensive dependency map.

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    After the initial discovery, you configure deletion strategies for each related CI type linked to the main CI, specifying what actions to take if Discovery cannot find those related CIs in subsequent runs. However, deletion strategies cannot be set for the main CI when using Infrastructure pattern types, only for related CIs. Main CIs can be deleted only if they belong to Application or Cloud Resource pattern types.

    Key Features

    • Related CI Types Configuration: You must manually define entries in the Related CI Types [sacitopattern] table for each relation between the main CI and related CI types. This is where deletion strategies are assigned.
    • Deletion Strategy Activation: Strategies apply only when Discovery successfully finds the main CI but cannot find a specific related CI during a discovery run.
    • Available Deletion Strategies for Related CIs:
      • Keep: Retains the related CI record without changes (default).
      • Delete: Removes the related CI record and its relationship to the main CI.
      • Mark as Absent: Sets the related CI’s installstatus to "Absent," indicating Discovery cannot find it, without deleting the record or relationships. Exceptions are network adapters and IP addresses, which are deleted if marked as absent.
      • Delete relations: Removes only the relationships between the related CI and the main CI, not the related CI itself.
      • Mark as Retired: Sets the related CI’s installstatus to "Retired," signaling it is no longer used by Discovery, without deleting the CI or relationships.
    • Main CI Deletion: Only allowed for Application or Cloud Resource pattern types, not for Infrastructure.
    • Exclusion: Deletion strategies do not apply to related entries, which are rules based on related CIs.

    Practical Implications for ServiceNow Customers

    By configuring CI deletion strategies in pattern discovery, you gain fine-grained control over how the CMDB handles stale or missing related CIs after repeated discoveries. This helps maintain CMDB accuracy by removing or flagging CIs no longer found by Discovery, without inadvertently deleting important records. Understanding and applying these strategies ensures your CMDB reflects the current environment and reduces manual cleanup efforts.

    When you perform discovery with a pattern, you can choose what to do with configuration items (CIs) that are in the Configuration Management Database (CMDB) but Discovery can no longer find.

    Note:
    Deletion strategies are available only with patterns, not probes/sensors.
    When you use a pattern to perform discovery, you identify a CI Type, which is the main CI you're trying to find, such as an IIS web server or Tomcat server. Discovery can also find related CIs and populate the CMDB accordingly. For example, after Discovery finds an IIS server with the IIS pattern, it can also find these related CIs:
    • The Windows machine that hosts the web server
    • The configuration files for the IIS server
    • The website that the IIS server hosts
    The dependency map on the main CI also shows the related CIs, as illustrated by the following graphic:
    Figure 1. An example of an IIS server main CI and its related CIs
    related CIs to an IIS server

    After you discover the main CI and its related CIs for the first time using a pattern, you must manually configure an entry in the Related CI Types [sa_ci_to_pattern] table for each relation between the main CI and a related CI type. These records are where you determine the deletion strategy for each related CI based on its type. Note that you cannot set a deletion strategy for the main CI for Infrastructure pattern type.

    You can view a list of the relations as the following image illustrates:
    Figure 2. Example CIs related to an IIS server
    CIs related to an IIS server
    The deletion strategy on a related CI takes effect when both of these conditions occur:
    • After you run Discovery with the pattern again.
    • Discovery successfully finds the main CI but cannot find the related CI.

    These deletion strategy options are available:

    Value Description
    Keep Preserves the configuration file CI record and makes no other changes to the record. This option is the default setting.
    Delete Deletes the configuration file CI record from the CMDB, and the relationship to the main CI.
    Mark as absent Marks the Status [install_status] field of the configuration file CI record as Absent, meaning that Discovery cannot find the tracked configuration file. This status does not instruct the system to delete the actual CI or the relationship.
    Note:
    There are two tables that do have their CIs deleted if marked as absent: cmdb_ci_network_adapter and cmdb_ci_ip_address.
    Delete relations Deletes only the CI relationships between the related CI and the main CI.
    Mark as retired Marks the Status [install_status] field of the configuration file CI record as Retired, meaning that Discovery no longer uses this configuration file. This status does not instruct the system to delete the actual CI or the relationship.
    Note:
    Deletion strategies are not available for related entries, which are rules that are based on related CIs. For more information, see Related entries.