Azure Virtual Machine Scale Sets (VMSS) Instance discovery

  • Release version: Yokohama
  • Updated July 31, 2025
  • 5 minutes to read
    • Summarize
    Summarized using AI
    This content was generated using new OpenAI-powered functionality. Results are provided on an as is basis and are not guaranteed to be accurate or complete.

    Summary of Azure Virtual Machine Scale Sets (VMSS) Instance Discovery

    This documentation describes how ServiceNow’s Discovery and Service Mapping Patterns application identifies Azure Virtual Machine Scale Sets (VMSS) and their instances using two key patterns:Azure - VM Scale Set (LP)andAzure VM Instance - Uniform Scale Set. VMSS allows you to create and manage groups of load-balanced virtual machines that can scale automatically based on demand or schedules.

    Show full answer Show less

    VMSS supports two orchestration modes:

    • Uniform Orchestration: Optimized for large-scale stateless workloads with identical VM instances based on a VM profile.
    • Flexible Orchestration: Supports high availability at scale with identical or multiple VM types, offering a unified Azure VM experience.

    Discovering these resources may require updating to the latest version of the Discovery and Service Mapping Patterns app from the ServiceNow Store.

    Prerequisites and Setup

    Before running discovery, verify Microsoft Azure discovery prerequisites, including correct credentials and permissions. Starting with version 1.31.0 of the patterns application, you can create Server Configuration Items (CIs) during cloud discovery without needing IP-based discovery, streamlining the process.

    Data Collected and CMDB Population

    Discovery populates multiple Configuration Item (CI) tables in the CMDB with detailed attributes for VMSS and related resources:

    • Instance Scale Set [cmdbciinstancescaleset]: Tracks install status, provisioning state, unique object ID, and name.
    • Virtual Machine Instance [cmdbcivminstance]: Records network adapters, state (e.g., On, Off), install and operational status, disk count, and total disk size.
    • Storage Volume [cmdbcistoragevolume]: Contains storage volume details including install and operational status.
    • Cloud Mgmt Network Interface [cmdbcinic]: Holds network interface information with status fields.
    • VNIC Endpoint [cmdbciendpointvnic]: Stores endpoint identifiers.
    • Image [cmdbciostemplate]: Contains OS image data, with a note that large volumes of records can be managed better by using the Cloud Image [cmdbcicloudosimage] table instead.
    • Hardware Type [cmdbcicomputetemplate]: Captures hardware type info; large record sets can be handled using the Cloud Hardware Type [cmdbcicloudhardwaretype] table.

    CI Relationships

    Discovery automatically establishes key relationships between CIs to represent the Azure VMSS environment accurately. Examples include:

    • Resource Group contains Instance Scale Sets.
    • Instance Scale Sets hosted on Azure Datacenters.
    • Instance Scale Sets consuming Load Balancer Pools.
    • Virtual Machine Instances managed by Instance Scale Sets and hosted on Azure Datacenters.
    • Storage Volumes and Network Interfaces linked to VM instances.
    • VM Instances provisioned from Hardware Types and Images.

    Tag Discovery

    Both VM Scale Set patterns collect Azure resource tags and store them as key-value pairs in the Key Value [cmdbkeyvalue] table, capturing tag names and values to support richer metadata and filtering capabilities.

    What This Enables for You

    • Automated discovery and accurate CMDB population of Azure VM Scale Sets and related virtual machines, improving visibility into your cloud environment.
    • Understanding of orchestration modes to align discovery with your Azure VMSS deployment type.
    • Comprehensive data capture including hardware, storage, networking, and operational states to support IT operations, change management, and service mapping.
    • Robust relationship modeling to reflect dependencies and infrastructure topology.
    • Tag collection for enhanced categorization and filtering of discovered resources.

    By leveraging these discovery patterns, ServiceNow customers can maintain up-to-date and detailed configuration data for Azure VMSS, supporting effective cloud management and operational processes.

    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 Microsoft Azure discovery prerequisites
    For more information, see the prerequisites section in Microsoft Azure Cloud components discovery using patterns.
    Create Server CIs during cloud discovery without running IP-based discovery
    Starting with Discovery and Service Mapping Patterns version 1.31.0, you can create Server CIs during cloud discovery without running IP-based discovery. For more information, see Server CI population during cloud discovery.

    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.