Azure Virtual Machine Scale Sets (VMSS) Instance discovery

  • Release version: Xanadu
  • Updated July 31, 2025
  • 4 minutes to read
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    Summary of Azure Virtual Machine Scale Sets (VMSS) Instance discovery

    Azure Virtual Machine Scale Sets (VMSS) enable you to create and manage a group of load-balanced virtual machines that can automatically scale in response to demand or schedules. ServiceNow's Discovery and Service Mapping Patterns application includes patterns specifically for discovering VMSS and their VM instances in Azure environments. These patterns require the latest version of the Discovery and Service Mapping Patterns app from the ServiceNow Store to ensure full compatibility and feature support.

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    VMSS operate in two orchestration modes: Uniform and Flexible. Uniform orchestrations use identical VM instances optimized for large-scale stateless workloads, while Flexible orchestration supports high availability with multiple VM types and provides a unified Azure VM experience.

    Key Features

    • Discovery Patterns:
      • Azure - VM Scale Set (LP) discovers instance scale sets and related resources.
      • Azure VM Instance - Uniform Scale Set discovers individual VM instances within uniform scale sets.
    • CMDB Population: Discovery populates multiple CMDB tables with detailed VMSS data including instance scale sets, VM instances, storage volumes, network interfaces, endpoints, OS images, and hardware types.
    • Tag Collection: Both patterns collect Azure resource tags and store them in the Key Value [cmdbkeyvalue] table to support metadata-driven management.
    • CI Relationships: Discovery creates and maintains relationships among scale sets, VM instances, storage, network interfaces, images, hardware types, and Azure datacenters to accurately represent dependencies and hosting configurations within the CMDB.
    • Prerequisites: Ensure Azure discovery prerequisites are met as documented in the Microsoft Azure Cloud components discovery guidance for successful pattern execution.

    Practical Benefits for ServiceNow Customers

    • Automated, detailed discovery of Azure VM Scale Sets and their virtual machines enables accurate asset and configuration management within the CMDB.
    • Maintaining up-to-date relationships and metadata facilitates impact analysis, change management, and service mapping activities.
    • Support for both Uniform and Flexible orchestration modes ensures compatibility with various Azure VMSS deployment models.
    • The tagging capability helps customers leverage Azure resource metadata for better categorization and automation within ServiceNow.
    • Using the latest Discovery and Service Mapping Patterns app ensures access to the most current features and bug fixes.

    Next Steps

    • Verify and fulfill Azure discovery prerequisites before running the VMSS discovery patterns.
    • Update or install the Discovery and Service Mapping Patterns application from the ServiceNow Store to the latest version.
    • Run the Azure - VM Scale Set (LP) and Azure VM Instance - Uniform Scale Set patterns to discover VMSS resources and populate the CMDB.
    • Review discovered CI relationships and tags in the CMDB to support operational use cases like monitoring, service mapping, and compliance.

    The Discovery and Service Mapping Patterns application uses the Azure - VM Scale Set (LP) and the Azure VM Instance - Uniform Scale Set patterns to find Azure Virtual Machine Scale Sets (VMSS). Discovering some of these resources may require updating to the latest version of the Discovery and Service Mapping Patterns application from the ServiceNow Store.

    VMSS let you create and manage a group of load balanced virtual machines (VMs). The number of VM instances can automatically increase or decrease in response to demand or a defined schedule. There Uniform Orchestration modes Flexible and achieve.
    • VMSS with Flexible Orchestration achieves high availability at scale with identical or multiple virtual machine types. With Flexible orchestration, Azure provides a unified experience across the Azure VM ecosystem.
    • VMSS with Uniform Orchestration optimized for large-scale stateless workloads with identical instances. VMSS with Uniform orchestration use a virtual machine profile or template to scale up to desired capacity. While there is some ability to manage or customize individual virtual machine instances, Uniform uses identical VM instances.

    Request apps on the Store

    Visit the ServiceNow Store website to view all the available apps and for information about submitting requests to the store. For cumulative release notes information for all released apps, see the ServiceNow Store version history release notes.

    To learn about VMSS and their versions that you can discover, refer to Detailed information on products discovered by ITOM Visibility.

    Prerequisites

    Verify the Azure discovery prerequisites section in Microsoft Azure Cloud components discovery using patterns.

    Data collected by Discovery during horizontal discovery

    Discovery populates the data in the CMDB when running the Azure - VM Scale Set (LP) Pattern.

    Table 1. Instance Scale Set [cmdb_ci_instance_scale_set]
    Field Description
    Install Status [install_status] Install status of the instance scale set. Default value is Installed.
    State [state] Provisioning state of the instance scale set. Possible values are Available or Terminated.
    Object ID [object_id] A unique identifier for the instance scale set.
    Name [name] Name of the instance scale set.

    Discovery populates the data in the CMDB when running the Azure VM Instance - Uniform Scale Set pattern.

    Table 2. Virtual Machine Instance [cmdb_ci_vm_instance]
    Field Description
    Network adapters [nics] Number of Network Interface Cards (NICs) attached to the virtual machine (VM) instance.
    State [state] Current state of the instance. For example: On, Off, or Terminated.
    Install Status [install_status] Install status of the instance. Default value is Installed.
    Operational status [operational_status] Operational status of the instance. Default value is Operational.
    Disks [disks] Number of disks attached to the instance.
    Disks size (GB) [disk_size] Total storage capacity of all disks attached to the VM, in gigabytes (GB).
    Table 3. Storage Volume [cmdb_ci_storage_volume]
    Field Description
    Name [name] Name or ID for the storage volume.
    Object ID [object_id] A unique identifier, allocated by Microsoft Azure for this resource.
    Install Status [install_status] Install status of the storage volume. Default value is Installed.
    Operational status [operational_status] Operational status of the storage volume. Default value is Operational.
    Table 4. Cloud Mgmt Network Interface [cmdb_ci_nic]
    Field Description
    Name [name] Name or ID for the network interface.
    Object ID [object_id] A unique identifier, allocated by Microsoft Azure for this resource.
    Install Status [install_status] Install status of the network interface. Default status is Installed.
    Operational status [operational_status] Operational status of the network interface. Default status is Operational.
    Table 5. VNIC Endpoint [cmdb_ci_endpoint_vnic]
    Field Description
    Name [name] Name or ID for the endpoint.
    Object ID [object_id] A unique identifier, allocated by Microsoft Azure for this resource.
    Table 6. Image [cmdb_ci_os_template]
    Field Description
    Name [name] Name or ID for the image.
    Object ID [object_id] A unique identifier, allocated by Microsoft Azure for this resource.
    Install Status [install_status] Install status of the image. Default value is Installed.
    Operational status [operational_status] Operational status of the image. Default value is operational.
    Note:
    When using the Image [cmdb_ci_os_template] table to store Cloud OS Images, you may notice an unusually large number of records. To avoid this issue, you can store the discovered OS images in the Cloud Image [cmdb_ci_cloud_os_image] table. For more information, see Enable Cloud OS Image discovery.
    Table 7. Hardware Type [cmdb_ci_compute_template]
    Field Description
    Name [name] Name of the hardware type.
    Note:
    When using the Hardware Type [cmdb_ci_compute_template] table to store the hardware types, you may notice an unusually large number of records. To avoid this issue, you can store the discovered hardware types in the Cloud Hardware Type [cmdb_ci_cloud_hardware_type] table. For more information, see Enable the Cloud Hardware Type class extension.

    CI relationships

    Discovery creates these relationships to support the VMSS discovery, when running the Azure - VM Scale Set (LP) pattern.

    CI Relationship CI
    Resource Group [cmdb_ci_resource_group] Contains::Contained by Instance Scale Set [cmdb_ci_instance_scale_set]
    Instance Scale Set [cmdb_ci_instance_scale_set] Hosted on::Hosts Azure Datacenter [cmdb_ci_azure_datacenter]
    Instance Scale Set [cmdb_ci_instance_scale_set] Consumes::Consumed by Load Balancer Pool [cmdb_ci_lb_pool]

    Discovery creates these relationships to support the VMSS discovery, when running the when running the Azure - VM Scale Set (LP) pattern.

    CI Relationship CI
    Virtual Machine Instance [cmdb_ci_vm_instance] Managed by::Manages Instance Scale Set [cmdb_ci_instance_scale_set]
    Storage Volume [cmdb_ci_storage_volume] Hosted on::Hosts Azure Datacenter [cmdb_ci_azure_datacenter]
    Block Endpoint [cmdb_ci_endpoint_block] Implement End Point To::Implement End Point From Storage Volume [cmdb_ci_storage_volume]
    Virtual Machine Instance [cmdb_ci_vm_instance] Use End Point To::Use End Point From Block Endpoint [cmdb_ci_endpoint_block]
    Virtual Machine Instance [cmdb_ci_vm_instance] Hosted on::Hosts Azure Datacenter [cmdb_ci_azure_datacenter]
    Hardware Type [cmdb_ci_compute_template] Hosted on::Hosts Azure Datacenter [cmdb_ci_azure_datacenter]
    Virtual Machine Instance [cmdb_ci_vm_instance] Provisioned From::Provisioned Hardware Type [cmdb_ci_compute_template]
    Virtual Machine Instance [cmdb_ci_vm_instance] Provisioned From::Provisioned Cloud Hardware Type [cmdb_ci_cloud_hardware_type]
    Cloud Mgmt Network Interface [cmdb_ci_nic] Hosted on::Hosts Azure Datacenter [cmdb_ci_azure_datacenter]
    Virtual Machine Instance [cmdb_ci_vm_instance] Implement End Point To::Implement End Point From Cloud Mgmt Network Interface [cmdb_ci_nic]
    Virtual Machine Instance [cmdb_ci_vm_instance] Use End Point To::Use End Point From VNIC Endpoint [cmdb_ci_endpoint_vnic]
    Virtual Machine Instance [cmdb_ci_vm_instance] Provisioned From::Provisioned Image [cmdb_ci_os_template]
    Image [cmdb_ci_os_template] Hosted on::Hosts Azure Datacenter [cmdb_ci_azure_datacenter]

    Tags discovery

    Both the Azure - VM Scale Set (LP) and the Azure VM Instance - Uniform Scale Set patterns collect tags and populate them in the Key Value [cmdb_key_value] table.
    Table 8. Key Value [cmdb_key_value]
    Field Description
    Key [key] Tag name.
    Value [value] Tag value.