CMDB alert grouping — properties and functionality

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  • Updated March 12, 2026
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    Summary of CMDB Alert Grouping — Properties and Functionality

    CMDB alert grouping enhances alert management by organizing alerts based on the relationships of configuration items (CIs). This functionality allows for more efficient alert aggregation, improving the overall effectiveness of incident response.

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    Key Features

    • Enable CMDB Correlation: Activating this property allows automatic aggregation of alerts based on CI relationships.
    • Max Relations Limit: Set a maximum number of CI relationships that can form a CMDB group, with a recommended limit of 3 for optimal performance.
    • All CMDB Relations: By default, all relationship types are used for grouping, but this can be adjusted to filter specific relations.
    • Advanced Use Cases: For specific scenarios, you can configure properties to exclude certain CI relationships from automatic group creation.
    • Suggested Relationships: Enable suggested relationships from the CMDB Group CI Relations table to enhance grouping accuracy.
    • Containment and Hosting Rules: These rules can be utilized to define which CI classes can exist within other classes when creating service templates.
    • Ignore Applicative Flow: Control whether CMDB groups form based on applicative flow relations, with the option to disable this feature.
    • CI Graph Reuse: A map of related CIs is stored to enhance search performance, with configurable storage periods.

    Key Outcomes

    By utilizing these properties, ServiceNow customers can effectively manage and organize alerts, leading to faster incident resolution and improved operational efficiency. Proper configuration of these settings ensures that alert grouping aligns with organizational needs and enhances the overall alert management process.

    Learn about the key properties and functionality of CMDB alert grouping, which facilitate efficient alert organization based on relationships and enhance the overall effectiveness of alert management.

    Properties for managing CMDB alert group creation

    Use the properties listed in the following tables to control CMDB alert group creation. For more information, see Configure scheduled job-based alert grouping.

    Property Setting

    Enable CMDB correlation

    sa_analytics.agg.query_cmdb_correlation_enabled

    Enable this property to automatically use CI relationships for alert aggregation, correlating alerts and creating CMDB alert groups.

    Max number of relations between CIs in a topology that form a CMDB group

    sa_analytics.agg.query_cmdb_graph_walk_nodes

    Set the maximum number of enabled relations between CIs in a topology that form a CMDB group.

    For example, if you set this property to 3, a CI associated with an alert will automatically be grouped with similar CIs within three hops or less.

    Note:
    This property setting impacts all types of relations used for alert aggregation. Using a value greater than 4 may negatively affect the performance of the alert aggregation job.

    Use all CMDB relations for CMDB group correlation

    evt_mgmt.related_cis_get_all_relation_types

    Set to true if you want to use all relationship types for CMDB grouping. The default setting for new users is that the option is set to true, meaning all relationship types are used for grouping. Set the property to false to filter the relations.

    Properties for managing automatic creation of CMDB alert groups for advanced use cases

    In some use cases, you may need to ignore or exclude certain CI relationships from automatic alert group creation. In this case, the evt_mgmt.related_cis_get_all_relation_types property must be set to false, and the properties in the below table must also be configured.
    Note:
    If the evt_mgmt.related_cis_get_all_relation_types property is set to false, and the relationship isn’t specified in the [em_suggested_relation_type] table, the relationship is not considered for alert aggregation.
    Table 1. Properties for managing automatic creation of CMDB alert groups for advanced use cases
    Property Setting

    Enable Suggested Relations for CMDB Correlation

    sa_analytics.agg.query_cmdb_suggested_relationship_enabled

    Keep this property enabled to use any suggested relationships defined in the CMDB Group CI Relations [em_suggested_relation_type] table when forming CMDB alert groups. To include a new relationship, add it to this table.

    This property is enabled by default.

    Use CMDB relationship based on host-containment Metadata rules

    evt_mgmt.related_cis_use_containment_rules

    Containment rules specify which configuration item classes can be contained within another item through a specific relationship when creating a service template.

    Keep this property enabled when forming CMDB alert groups to use any host-containment rules defined in the Metadata Editor. For more details, see CMDB dependent relationship rules.

    This property is enabled by default.

    Enable filtering by dependent relationship rules

    evt_mgmt.related_cis_use_hosting_rules

    Hosting rules define what classes of configuration items are hosted on other classes of configuration items.

    Keep this property enabled when forming CMDB alert groups to apply any hosting rules, which define which classes of configuration items are hosted on other classes.

    This property is hidden and enabled by default.
    Note:
    If you need to change the default value, add the property, as it does not exist in the instance by default. For more information on how to create a property, see Add a system property.

    Ignore CMDB alert groups from forming due to CI applicative flow relations

    sa_analytics.agg.ignore_cmdb_applicative_flow

    Set this property to true to prevent CMDB groups from forming based on applicative flow relations for CI relations in application services.

    This property is hidden and enabled by default.
    Note:
    If you need to change the default value, add the property, as it does not exist in the instance by default. For more information on how to create a property, see Add a system property.

    sa_analytics.applicative_flow_rc_enabled

    This property is hidden and enabled by default.

    Event Management stores a map of related CIs in the Event Management CI Graph Reuse [em_ci_graph_reuse] table for each processed CI. You can adjust the storage period by modifying the sa_analytics.agg.query_cmdb_graph_reuse_period property, with the default set to one day (86,400 seconds). This process enhances the search performance of relations in the CMDB. To disable the storage process during advanced use-case configurations, set the property value to zero.
    Note:
    If you need to change the default value, add the sa_analytics.agg.query_cmdb_graph_reuse_period property, as it does not exist in the instance by default. For more information on how to create a property, see Add a system property.