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Azure Database Support Blog
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Auto scale up/down the Managed instance

amanda_ibrahim's avatar
amanda_ibrahim
Icon for Microsoft rankMicrosoft
Sep 20, 2022
Request: If the customer needs to configure auto scaling for SQL Managed Instance, where the vCores can be increase and decrease automatically on specific time.   Solution: You may take a loo...
Updated Sep 20, 2022
Version 2.0
amanda_ibrahim's avatar
amanda_ibrahim
Icon for Microsoft rankMicrosoft
Jul 16, 2023

Since run as account will be deprecated soon:

 

then you can customize this runbook to use Managed identity for authentication Tutorial - Create a PowerShell Workflow runbook in Azure Automation | Microsoft Learn.

 

If you have the runbook already exists then you can follow the steps in this link to migrate to Managed identity Migrate from a Run As account to Managed identities | Microsoft Learn, or you can create a new runbook with Managed identity and then you can assign the required roles for the runbook at Subscription level, below is a screenshot of the role permission from my lab:

 

below is updated script using System identity instead of run as account:

param(
[parameter(Mandatory=$false)]
[string] $environmentName = "AzureCloud",   

[parameter(Mandatory=$true)]
[string] $resourceGroupName,

[parameter(Mandatory=$true)]
[string] $MIName,

[parameter(Mandatory=$false)]
[string] $defaultEdition = "GeneralPurpose",

[parameter(Mandatory=$false)]
[string] $defaultvCores = "4",

[parameter(Mandatory=$false)]
[string] $defaultStorageSizeInGB = "32",

[parameter(Mandatory=$false)]
[string] $defaultComputeGeneration = "Gen5"

)

filter timestamp {"[$(Get-Date -Format G)]: $_"}
Write-Output "Script started." | timestamp

try
{

# Ensures you do not inherit an AzContext in your runbook
Disable-AzContextAutosave -Scope Process

# Connect to Azure with system-assigned managed identity
Connect-AzAccount -Identity

# set and store context
$AzureContext = Set-AzContext –SubscriptionId "put your SubscriptionId here"   

Write-Output "Authenticated with Managed identity."  | timestamp
}
catch 
{
    if (!$AzureContext)
        {
            $ErrorMessage = "Connection not found."
                throw $ErrorMessage
            } else{
                Write-Error -Message $_.Exception
                throw $_.Exception
            }
}

# Get the MI object
try
{
    $sqlMI = Get-AzSqlInstance -Name $MIName -ResourceGroupName $ResourceGroupName
    Write-Output "MI name: $($sqlMI.ManagedInstanceName)" | timestamp
    if ($sqlMI.ManagedInstanceName -ne "")
    {
        Write-Output "Current MI vCores: $($sqlMI.VCores), Storage: $($sqlMI.StorageSizeInGB)" | timestamp

            Write-Output "---> Scaling schedule found. Check if current edition/tier is matching..." | timestamp
            if($sqlMI.VCores -ne $defaultvCores -or $sqlMI.StorageSizeInGB -ne $defaultStorageSizeInGB)
            {
                Write-Output "--- ---> vCores and/or Storage Size are different. Changing!" | timestamp
                Set-AzSqlInstance -Name $MIName -ResourceGroupName $ResourceGroupName -VCore $defaultvCores -StorageSizeInGB $defaultStorageSizeInGB -ComputeGeneration $defaultComputeGeneration -Edition $defaultEdition -Force -Confirm:$false | out-null

                Write-Output "Change to vCores/Sotrage size as specified in scaling schedule initiated..." | timestamp
                
                $sqlMI = Get-AzSqlInstance -Name $MIName -ResourceGroupName $ResourceGroupName
                Write-Output "Current MI vCores: $($sqlMI.VCores), Storage: $($sqlMI.StorageSizeInGB)" | timestamp
            }
            else
            {
                Write-Output "Current MI vCores and/or Sotrage size matches the scaling schedule already. Exiting..." | timestamp
            }
    }
    else{
        Write-Error "Could not retrieve MI details" | timestamp
    }
}
catch 
{
    Write-Error -Message $_.Exception
    throw $_.Exception
        
}
Write-Output "Script finished." | timestamp