Create an instance pool (preview) - Azure SQL Managed Instance

Applies to: Azure SQL Managed Instance

This article teaches how to create an instance pool for Azure SQL Managed Instance by using the Azure portal, PowerShell, or the Azure CLI, as well as how to move instances in and out of the pool by using PowerShell, or the Azure CLI.

Instance pools make it possible to deploy multiple instances with shared resources to a single virtual machine, which provides a convenient and cost-effective infrastructure to migrate multiple SQL Server instances without having to consolidate smaller and less compute-intensive workloads onto a larger SQL Managed Instance.

Note

Instance pools for Azure SQL Managed Instance are currently in preview.

Prerequisites

To create an instance pool, you should have:

Subnet size considerations

Carefully plan the size of your subnet when you use an instance pool. Refer to Determine required subnet size & range for subnet sizing guidelines.

Use the following formula when calculating the number of IP addresses required by one instance pool that contains multiple General Purpose instances:

2 * (5 + (3 * # of MIs)) + 5

The # of MIs refers to the maximum potential number of instances you plan to provision. The maximum possible number of instances in a pool is 40.

Create instance pool

You can create an instance pool by using the Azure portal, PowerShell or the Azure CLI. Consider the following:

  • Only the General Purpose service tier on either standard-series (Gen5) or premium-series hardware is currently available.
  • The pool name can contain only lowercase letters, numbers and hyphens, and can't start with a hyphen.
  • The Azure Hybrid Benefit is applied at the instance pool level. You can set the license type when you create the pool, and update the license type after the pool is created.

Important

Deploying an instance pool is a long running operation that can take up to 4.5 hours.

To create an instance pool in the Azure portal, follow these steps:

  1. Search for instance pools in the Azure portal and select the Instance pools service to open the Instance pools page:

    Screenshot searching for instance pools in the Azure portal.

  2. On the Instance pools page, select + Create to open the Create Azure SQL Managed Instance Pool page:

    Screenshot of the Instance pools page in the Azure portal, with +Create selected.

  3. On the Create Azure SQL Managed Instance Pool:

    1. Provide project and instance details on the Basics tab.
    2. Use Configure instance pool under Compute + storage to open the Compute + Storage page and choose the service tier, compute hardware and SQL Server license that you want the pool to use. Use Apply to save your compute settings and go back to the Create Azure SQL Managed Instance Pool page.
    3. Select an existing virtual network, or configure a new virtual network on the Networking tab.
    4. (Optional) Configure a non-default maintenance window for the pool on the Additional settings tab.
    5. Review your configuration on the Review + create tab, and then select Create to create your instance pool.

    Screenshot of the Create Azure SQL Managed Instance Pool page in the Azure portal, with Configure instance pool selected.

  4. You can monitor pool deployment from Notifications.

After your instance pool is created, you can create a new instance in the pool by using the Azure portal, or you can move an existing instance into the pool by using PowerShell or the Azure CLI.

Create new instance inside pool

After your pool is created, you can create a new instance within the pool by using the Azure portal, PowerShell, or the Azure CLI.

Consider the following:

  • You must specify the license type for the new instance, and it must match the license type of the pool.

To create a new instance inside a pool by using the Azure portal, follow these steps:

  1. Go to the Azure SQL page in the Azure portal.

  2. On the Azure SQL page, select + Create to open the Select SQL deployment option.

  3. On the SQL managed instances tile, choose Single instance as the resource type and then select Create to open the Create Azure SQL Managed Instance page.

  4. On the Basics tab of the Create Azure SQL Managed Instance page:

    1. Select the resource group that contains your existing instance pool.
    2. Choose Yes to Belongs to an instance pool? under Managed Instance details to create your new instance inside an instance pool.
    3. Select the pool from the Instance pool dropdown list.

    Screenshot of the Create Azure SQL Managed Instance page in the Azure portal with belongs to an instance pool selected.

  5. Fill out the remaining details on the Create Azure SQL Managed Instance page to create your instance inside the pool. For details, review Create Azure SQL Managed Instance.

  6. Select Review + create to review settings for your new instance and then use Create to deploy your instance inside the selected pool.

Move existing instance

You can move an existing instance into and out of a pool by using PowerShell or the Azure CLI if:

  • It's in the same resource group as the pool.
  • It's on the same virtual network and subnet as the pool.
  • It fits the instance pool resource limits.

When an existing instance is moved into a pool, settings at the pool level take precedence over instance-level settings. For example, the instance inherits the license type and maintenance window set at the pool level. When an instance is moved out of the pool, it retains the settings it inherited from the pool. The only exception is with the license type, which defaults back to 'LicenseIncluded' when an instance is removed from the instance pool - the Azure Hybrid Benefit and hybrid failover rights benefit must be configured manually after an instance is moved out of a pool.

Moving an existing instance inside a pool by using the Azure portal is not currently supported.

To move an instance into a pool with PowerShell, provide the pool name when you use Set-AzSqlInstance:

$instance01 | Set-AzSqlInstance -InstancePoolName $instancePoolName

To move an instance out of a pool, provide a blank pool name:

$instance01 | Set-AzSqlInstance -InstancePoolName ''

Connect to instance in a pool

You can choose to connect to an instance in a pool with either a private endpoint, or a public endpoint. To use a private endpoint, you'll need to use the Azure Private Link.

To connect to an instance in a pool with a public endpoint, you need to enable the endpoint and then allow public endpoint traffic on the network security group.

Create a database

Creating a database for an instance inside a pool is the same as creating a database for a single instance. You can create a new database by using the Azure portal, PowerShell or the Azure CLI.

To create a new database for an existing SQL managed instance by using the Azure portal, follow these steps:

  1. Go to your SQL managed instance in the Azure portal.
  2. On the Overview pane, select + New database from the command bar to open the Create Azure SQL Managed Database page.
  3. Provide details for the new database.
  4. Select Review + create to review your new database configuration and then use Create to deploy your database.

Get pool usage

You can use PowerShell to determine how resources are being used inside a pool.

To get a list of instances inside a pool, use Get-AzSqlInstance:

$instancePool | Get-AzSqlInstance

To get pool resource usage, use Get-AzSqlInstancePoolUsage:

$instancePool| Get-AzSqlInstancePoolUsage

You can add the -ExpandChildren parameter to get a detailed overview of the pool and instances inside it:

$instancePool | Get-AzSqlInstancePoolUsage –ExpandChildren

To list the databases in an instance, use Get-AzSqlInstanceDatabase:

$databaseParams = @{
    InstanceName = $instance01Name
    ResourceGroupName = $resourceGroupName
}

$databases = Get-AzSqlInstanceDatabase @databaseParams

Note

To check limits on the instances deployed to a pool, and databases per instance pool, review resource limits.

Update an instance pool

You can update settings for an existing instance pool by using PowerShell or the Azure CLI.

You can use PowerShell to make changes to the instance pool limits.

The following sample script changes the license type, vCore size, and hardware type:

Change license type:

$instancePoolParams = @{
    LicenseType = "BasePrice"
    VCores = 16
    ComputeGeneration = "Gen8"
}
$instancePool | Set-AzSqlInstancePool @instancePoolParams

You can also determine the available maintenance window schedules:

$parameters = @{
    Location = $location
    MaintenanceScope = "SQLManagedInstance"
}
 
$configurations = Get-AzMaintenancePublicConfiguration @parameters
$maintenanceWindowOptions = $configurations | Where-Object { $_.Location -eq $location -and $_.MaintenanceScope -eq "SQLManagedInstance" }

And then you can change the maintenance window by specifying a window option, such as:

$instancePoolParams = @{
    MaintenanceConfigurationId = $maintenanceWindowOptions[1].Id
}

$instancePool | Set-AzSqlInstancePool @instancePoolParams

Update a pooled instance

If pool resource limits haven't been exceeded, you can modify resource configurations for an instance inside a pool using PowerShell or the Azure CLI,

To modify resource parameters for an instance inside a pool, use Set-AzSqlInstance.

The following sample updates the vCores to 8 and changes the storage size to 512 GB for Instance1:

$instancePoolParams = @{
    VCore = 8
    StorageSizeInGB = 512
    InstancePoolName = $instancePoolName
}

$instance1name | Set-AzSqlInstance @instancePoolParams

Delete an instance pool

You can delete an instance pool by using PowerShell or the Azure CLI, once all instances in the pool have either been deleted, or moved out of the pool.

To delete an instance pool, use Remove-AzSqlInstancePool.

The following sample script deletes an empty instance pool:

$params = @{
    ResourceGroupName = "<resource group name>"
    Name = "<instance pool name>"
}

Remove-AzSqlInstancePool @params

Instance pool operations

The following table shows available instance pool operations:

Command Azure portal PowerShell Azure CLI
Create an instance pool Yes Yes Yes
Update pool properties No Yes Yes
Check a pool use and properties Yes Yes Yes
Delete an instance pool Yes Yes Yes
Create new managed instance inside a pool Yes Yes Yes
Move a managed instance into a pool No Yes Yes
Delete a managed instance from a pool Yes Yes Yes
Move a managed instance out of a pool No Yes Yes
Create a database in instance within a pool Yes Yes Yes
Delete a database from SQL Managed Instance Yes Yes Yes

To use PowerShell, install the latest version of PowerShell Core, and follow instructions to Install the Azure PowerShell module.

Available PowerShell commands:

Cmdlet Description
New-AzSqlInstancePool Creates an instance pool.
Get-AzSqlInstancePool Returns information about an instance pool.
Set-AzSqlInstancePool Sets properties for an instance pool.
Remove-AzSqlInstancePool Removes an instance pool.
Get-AzSqlInstancePoolUsage Returns information about instance pool usage.

For operations related to instances both inside pools and single instances, use the standard managed instance commands, but the instance pool name property must be populated when using these commands for an instance in a pool.

Limitations

During public preview, instances in a pool have the following limitations:

  • The pool name can contain only lowercase letters, numbers and hyphens, and can't start with a hyphen.
  • All instances in the pool use the same licensing model. When you specify a license model for an instance that is different than the license model for the pool, the pool license model is used. When the instance is moved out of the pool, it automatically switches to a full paid license (LicenseType = 'LicenseIncluded'). Manually activate the Azure Hybrid Benefit or the hybrid failover rights benefit to change the licensing model.
  • Pooled instances must belong to the same subnet and resource group. Moving an instance in and out of the pool is only possible within the subnet of the pool and same resource group.
  • Only the General Purpose service tier is available on standard-series (Gen5) or premium-series hardware. The Next-gen General Purpose, Business Critical service tier, and premium-series memory optimized hardware isn't available.
  • The maximum possible number of instances in the pool is 40.
  • An instance pool can only be deleted after all instances in the pool are either deleted or moved out of the pool.
  • You can't use the Azure portal to:
    • Configure the instance pool. Use PowerShell or the Azure CLI instead.
    • Move instances in and out of the pool. Use PowerShell or the Azure CLI instead.
  • The following SQL Managed Instance features aren't supported when instances are in a pool:

Support requests

Create and manage support requests for instance pools in the Azure portal.

To create a new support request in the Azure portal, follow these steps:

  1. Open the New support request page in the Azure portal.

  2. On the New support request, provide the following information:

    1. For Issue type, select Technical.
    2. Choose the appropriate Subscription from the dropdown list.
    3. For the Service type, select SQL Managed Instance.
    4. For Resource, provide the name of your SQL Managed Instance if it exists, or select General question if you're not able to deploy your instance inside the pool.
    5. For Summary, type instance pools.
    6. For Problem type, choose Create, Scale, Stop, Start, or Delete Resources.
    7. For Problem Subtype, choose Instance Pools.

    Screenshot of the Instance pools support request in the Azure portal.

  3. Select Next on the subsequent pages until you're able to Create your support request.

To create larger SQL Managed Instance deployments (with or without instance pools), you might need to obtain a larger regional quota. For more information, see Request quota increases for Azure SQL Database. The deployment logic for instance pools compares total vCore consumption at the pool level against your quota to determine whether you're allowed to create new resources without further increasing your quota.