Refresh databases that belongs to Availability Group using dbatools
Few days ago I was surfing on Twitter when dbatools asked about how it’s PowerShell module changed the way people work.
Open and check the answers given by the community as there is really good stuff there!
I have shared one of my recipes related to database refreshes. You know, when the client says, “please restore this backup or the most recent backup on our instance.”. But what if the databases belong to an availability group? It’s not as simple as a standalone installation.
Not so fast - A couple of notes
- Read carefully what each command does as you normally do for every single script you use from the internet. You do that, right? :-)
- I have used multiple times but always only on Availability Groups with 2 nodes.
- It’s written to use automatic seeding.
- You can, and you should, run the script command by command in your first try as this will be much easier to understand how it’s working.
Variations that you may need
- With some changes you can put it to work with Availability Groups with more than 2 nodes. The failover and the set dbowner part is the one that is being done just having 2 nodes in mind.
- If you have huge databases and automatic seeding is not an option for you, you may want to leverage on the backup/restore process. Take a look on the Add-DbaAgDatabase command docs (look to
-SharedPathparameter along with
<# Author: Cláudio Silva Blog: https://claudioessilva.eu Twitter: https://twitter.com/claudioessilva Date: 2020/05/19 .SYNOPSIS The goal of this script is to provide an automatic way to refresh one or more databases that belongs to an Availability Group. .Description The script is doing the following major steps 1 - Get the replicas (Primary and Secondary) 2 - Export user permissions of the current databases (before dropping them) 3 - Remove databases from the Availability Group (on primary node) 4 - Restore the backups with overwrite NOTE: Here I left two options: - one (the commented) is when the databases on the destination instance have the same name as the origin - The 2nd one that will be running assumes that you will need to give a different name to the database on the destination instance. (Example: Database called 'carrots' is 'carrots_PROD' on destination instance) 5 - Run the script exported on step 2 6 - Repair orphaned users 7 - Remove orphaned users 8 - Remove databases from the secondary node 9 - Add the restored databases to the availability group using Automatic Seeding 10 - Set the dbowner of the databases 11 - Test failover 12 - Set the dbowner of the databases on this node 13 - Test failback #> $listenerName = "listener" $availabilityGroupName = "AGName" $databases = "db1", "db2" # Add more if you need. Also if using the 2nd method of restore, add there too. $dboLogin = "dbOwnerLogin" $exportUserPath = "<Path>\Exported_Users_$availabilityGroupName.sql" $DestinationDataDirectory = "<pathToYourDataDirectory" $DestinationLogDirectory = "<pathToYourLogDirectory" $backupDirectory = "<pathToYourBackups>" # Get AG replicas $agReplicas = Get-DbaAgReplica -SqlInstance $listenerName -AvailabilityGroup $availabilityGroupName # Get current primary node $primaryNode = ($agReplicas | Where-Object role -eq 'Primary').Name # Get secondary node $secondaryNode = ($agReplicas | Where-Object role -eq 'Secondary').Name # Export users permissions Export-DbaUser -SqlInstance $sqlinstance -Database $databases -Path $exportUserPath # Remove the databses from the AG Remove-DbaAgDatabase -SqlInstance $primaryNode -AvailabilityGroup $availabilityGroupName -Database $databases #-Confirm:$false # Restore databases with overwrite # Restore databases with overwrite # 1 - You can get all backups from a folder pipe to Restore-DbaDatabase and it will do the magic. # Restore databases with overwrite # 1 - You can get all backups from a folder pipe to Restore-DbaDatabase and it will do the magic. # Get-ChildItem -Path $backupDirectory -Recurse -Filter "*.bak" | Restore-DbaDatabase -SqlInstance $sqlinstance -WithReplace -DestinationDataDirectory $DestinationDataDirectory -DestinationLogDirectory $DestinationLogDirectory # 2 - If you need to restore the database with a different name, you may prefer to specify each -Database name from the specific backup # NOTE: This will keep the database name. Restore-DbaDatabase -SqlInstance $primaryNode -DatabaseName 'db1' -Path "$backupDirectory\db1.bak" -WithReplace -DestinationDataDirectory $DestinationDataDirectory -DestinationLogDirectory $DestinationLogDirectory Restore-DbaDatabase -SqlInstance $primaryNode -DatabaseName 'db2' -Path "$backupDirectory\db2.bak" -WithReplace -DestinationDataDirectory $DestinationDataDirectory -DestinationLogDirectory $DestinationLogDirectory # Put the permissions back # Put the permissions back # Note: We need to replace the 'GO' batch separator as Invoke-DbaQuery will do this split and send execution one-by-one. This means that a database context change works but then next command will probably be run on master Invoke-DbaQuery -SqlInstance $primaryNode -Query $((Get-Content $exportUserPath) -replace '\bGO\b', ' ') # Repair Orphan Users Repair-DbaDbOrphanUser -SqlInstance $primaryNode -Database $databases # Remove Orphan Users Remove-DbaDbOrphanUser -SqlInstance $primaryNode -Database $database # Remove databases from the secondary instance Remove-DbaDatabase -SqlInstance $secondaryNode -Database $databases #-Confirm:$false # Add databases to the AG using 'Automatic' option for -SeedingMode parameter Add-DbaAgDatabase -SqlInstance $primaryNode -AvailabilityGroup $availabilityGroupName -Database $databases -SeedingMode Automatic #-Confirm:$false # Change database owner on the primary Set-DbaDbOwner -SqlInstance $primaryNode -Database $databases -TargetLogin $dboLogin # Failover the AG so we can set database DB Invoke-DbaAgFailover -SqlInstance $secondaryNode -AvailabilityGroup $availabilityGroupName # Change database owner Set-DbaDbOwner -SqlInstance $secondaryNode -Database $databases -TargetLogin $dboLogin # Failover back if wanted/needed Invoke-DbaAgFailover -SqlInstance $primaryNode -AvailabilityGroup $availabilityGroupName
What do you need to change
1 - Fill the variable values from lines 27 to 34. 2 - Select your method of restore / seeding. Lines 51 to 59.
Same task but not for databases within Availability Groups
With this script as a starting point you can adapt to do refreshes of databases that work on single instances.
I hope you find it useful. As a time metric I can tell you that (excluding restores/seeding) all the other actions took me about 15min to run manually with a lot of possible things to go wrong. Now it takes me 5min or less.
If you are facing difficulties, drop a comment.
Thanks for reading!