Tuesday, 31 December 2019

Schedule start & stop of Azure Analysis Services (Az)

Case
To save some money on my Azure Bill, I want to pause my Azure Analysis Services (AAS) at night when nobody is using it and then resume it in the morning. How do you arrange that in Azure?
Save some money on your Azure Bill by pausing AAS



















Solution
A few years ago we showed you how to do this with some PowerShell code in an Azure Automation Runbook with the AzureRM modules. However these old modules will be be out of support by the end of 2020. So now it is time to change those scripts.

1) Create Automation Account
First we need to create an Automation Account. If you already have one with the Run As Account enabled then you can skip this step.
  • Go to the Azure portal and create a new resource
  • Search for automation
  • Select Automation Account
  • Choose a useful name for the Automation Account
  • Select your Subscription, Resource Group and the Region
  • For this example we will use the Azure Run As account. So make sure to enable it and then click on the Create button.
Create Azure Automation Account
















2) Add Module Az.AnalysisServices
Before we start writing some code we need to add a PowerShell module called Az.AnalysisServices. This module contains methods we need in our code to pause and resume Azure Analysis Services. But first we need to add Az.Accounts because Az.AnalysisServices depends on it.

If you forget this step you will get error messages while running your code that state that some of your commands are not recognized:
Get-AzAnalysisServicesServer : The term 'Get-AzAnalysisServicesServer' is not recognized as the name of a cmdlet, function, script 
file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct 
and try again.
  • Go to the newly created Azure Automation Account
  • Go to Modules in the left menu
  • Click on the Browse Gallery button
  • Search for Az.Accounts
  • Click on Az.Accounts in the result and import this module
  • Also search for Az.AnalysisServices (but wait until Az.Accounts is actually imported)
  • Click on Az.AnalysisServices in the result and import this module
Adding a new module to your Automation Account














Note: if you are using an existing Automation Account then you probably already added Az.Accounts.

3) Create Runbook
Now we are ready to create a runbook in the Azure Automation Account and start writing some PowerShell code.
  • Go back to the overview page of your newly created Azure Automation Account
  • Click on Runbooks in the left menu
  • Click on the + Create a runbook button to create a new Runbook
  • Enter a descriptive name for the Runbook like StartStopAas
  • Select PowerShell as Runbook type
  • Optionally add a description and click on the Create button
Create a Runbook














4) Edit Runbook code
Next edit the new Runbook if it wasn't already opened by the previous step. Copy the code below and paste it in the editor. Then study the code and its comments to understand the code that can both start and stop your Azure Analysis Services (AAS). It exists of five parts:
  1. Parameters
  2. Log in to Azure
  3. Get current state
  4. Pause or Resume
  5. Logging
Parameters
To pause or resume the script needs three parameters. The first parameter 'AasAction' is a string that indicates whether you want to stop or start the AAS. The second parameter 'ResourceGroupName' indicates the location (resourcegroup) of your AAS and the last parameter 'AnalysisServerName' is the name of your AAS. There are a couple of validations which you could extend to make your script even more monkey proof.
Note: if you want to call this script via Azure Data Factory (ADF), then you need to change the parameter part. You can find all the details to do that in our blog posts about Runbook parameters and ADF and using the Webhook activity in ADF. If this is your first time creating a runbook then first try the standard script and then adjust it to your needs.

Log in to Azure
This is a standard piece of code that you will see in all of our examples. Please read our blog post about the Azure Run as Account for more detailed information.

Get current state
This piece of code tests whether it can find the AAS and gets its current state. It stores the current state and uses it later on for an extra check when pausing or resuming the AAS.

Pause or Resume
This is the actual code for pausing or resuming the AAS. There is an extra check to compare the current state with the new desired state. It now throws an error when you want to pause an AAS that is already paused. You could change that to write an warning instead of an error.
Note: you could also send emails to notify you of any errors

Logging
The last piece of code is for logging purposes. It shows you that it successfully changed the state of the AAS and how long it took to accomplish that.

# PowerShell code

########################################################
# Parameters
########################################################
[CmdletBinding()]
param(
    [Parameter(Mandatory=$True,Position=0)]
    [ValidateSet('Start','Stop')]
    [string]$AasAction,
    
    [Parameter(Mandatory=$True,Position=1)]
    [ValidateLength(1,100)]
    [string]$ResourceGroupName,

    [Parameter(Mandatory=$True,Position=2)]
    [ValidateLength(1,100)]
    [string]$AnalysisServerName
)

# Keep track of time
$StartDate=(GET-DATE)



########################################################
# Log in to Azure with AZ (standard code)
########################################################
Write-Verbose -Message 'Connecting to Azure'
 
# Name of the Azure Run As connection
$ConnectionName = 'AzureRunAsConnection'
try
{
    # Get the connection properties
    $ServicePrincipalConnection = Get-AutomationConnection -Name $ConnectionName       
  
    'Log in to Azure...'
    $null = Connect-AzAccount `
        -ServicePrincipal `
        -TenantId $ServicePrincipalConnection.TenantId `
        -ApplicationId $ServicePrincipalConnection.ApplicationId `
        -CertificateThumbprint $ServicePrincipalConnection.CertificateThumbprint 
}
catch 
{
    if (!$ServicePrincipalConnection)
    {
        # You forgot to turn on 'Create Azure Run As account' 
        $ErrorMessage = "Connection $ConnectionName not found."
        throw $ErrorMessage
    }
    else
    {
        # Something else went wrong
        Write-Error -Message $_.Exception.Message
        throw $_.Exception
    }
}
########################################################
 


########################################################
# Getting the AAS for testing and logging purposes
########################################################
$myAzureAnalysisServer = Get-AzAnalysisServicesServer -ResourceGroupName $ResourceGroupName -Name $AnalysisServerName
if (!$myAzureAnalysisServer)
{
    Write-Error "$($AnalysisServerName) not found in $($ResourceGroupName)"
    return
}
else
{
    Write-Output "Current status of $($AnalysisServerName): $($myAzureAnalysisServer.State)"
}



########################################################
# Pause or Resume AAS
########################################################
# Check for incompatible actions
if (($AasAction -eq "Start" -And $myAzureAnalysisServer.State -eq "Succeeded") -Or ($AasAction -eq "Stop" -And $myAzureAnalysisServer.State -eq "Paused"))
{
    Write-Error "Cannot $($AasAction) $($AnalysisServerName) while the status is $($myAzureAnalysisServer.State)"
    return
}
# Resume Azure Analysis Services
elseif ($AasAction -eq "Start")
{
    Write-Output "Now starting $($AnalysisServerName)"
    $null = Resume-AzAnalysisServicesServer -ResourceGroupName $ResourceGroupName -Name $AnalysisServerName
}
# Pause Azure Analysis Services
else
{
    Write-Output "Now stopping $($AnalysisServerName)"
    $null = Suspend-AzAnalysisServicesServer -ResourceGroupName $ResourceGroupName -Name $AnalysisServerName
}



########################################################
# Show when finished
########################################################
$Duration = NEW-TIMESPAN –Start $StartDate –End (GET-DATE)
Write-Output "Done in $([int]$Duration.TotalMinutes) minute(s) and $([int]$Duration.Seconds) second(s)"

5) Testing
Testing the functionality of your code can be done in the runbook editor. Click on the Test pane button above your script. After that you need to fill in the parameters and hit the Start button to execute the script.
Testing your script















6) Scheduling Runbook
To schedule your runbook in Azure Automation you first need to publish it via the Runbook editor. After it has been published you can add a schedule to this runbook.
  • Edit the script in the runbook editor
  • Click on publish (the editor will close and you will be redirected to the overview page)
  • In the overview page click on Link to schedule
  • In the Schedule menu you can select an existing schedule or create a new one
  • In the Parameter menu you can provide the value for the parameters
Add schedule to runbook















Note: If you have multiple Azure Analysis Services that you all want to pause/resume on the same time then you have a slight problem because you cannot reuse a schedule for the same runbook multiple times with different parameters (please upvote or add a comment). Workarounds:

  1. create multiple identical schedules (ugly but works)
  2. do everything in one big script (less flexible but works)
Log of runbook executions















Summary
In this blog post you learned how to schedule a stop and start for your Azure Analysis Services to save money in case you don't need it to be live 24*7. Scheduling is done in Azure Automation, but with some minor changes you can also do that via an ADF pipeline.

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