Setting up SQL Managed Instance Link to an Availability Group (Updated September 2025)
On a recent case, a customer was trying to set up SQL Managed Instance Link to partner with an on premise Always On Availability Group (AG). Using the public documentation will work, but there are some differences required to ensure a failover does not break the connection. Please note that Managed Instance Link can only be created with an availability group with a single database. This post will be using steps from the following documents. Prepare your environment for a link - Azure SQL Managed Instance Configure link with scripts - Azure SQL Managed Instance The steps to set this up are below Create a database master key on the AG nodes Enabling trace flags on the AG nodes (Optional) Testing network connectivity between SQL Managed Instance and the AG Create certificates on the AG nodes Import AG certificate public keys to SQL Managed Instance Import the certificate public key of the SQL Managed Instance to AG nodes Import Azure-trusted root certificate authority keys to AG nodes Alter the mirroring endpoint on AG nodes Create a distributed availability group on AG Set up the managed Instance Link Create a database master key Firstly, a master encryption key is required on all nodes of the AG if it does not already exist. The script below will not return any rows if it does not exist. -- Run on SQL Server USE master; GO SELECT * FROM sys.symmetric_keys WHERE name LIKE '%DatabaseMasterKey%'; If no rows are returned, the following query can be used. Keep a note of the passwords in a confidential and secure place. -- Run on SQL Server -- Create a master key USE master; GO CREATE MASTER KEY ENCRYPTION BY PASSWORD = '<strong_password>'; Enabling trace flags on AG nodes (Optional) To optimise the performance of the link, we recommend enabling the trace flags T1800 and T9567 on all nodes. Instructions on this are here and will require a restart of the service. Testing network connectivity between SQL Managed Instance and the AG Instructions on how to run the connectivity tests can be found here, and can be done by SSMS GUI or T-SQL. For these tests, the SQL Managed Instance will need to be able to connect to the Mirror endpoint using the IP of the availability group. The SQL Managed Instance IPs can can change (for example during maintenance). For that reason NSG and firewall rules should allow access to ports 5022 and 11000-11999 for the whole subnet range of the SQL Managed Instance. Create certificates on AG nodes The below query will need to be run on all AG nodes. Pay particular attention to the @cert_expiry_date variable to ensure it is a date in the future. It will need to be replaced after expiry. -- Create the SQL Server certificate for the instance link USE MASTER -- Customize SQL Server certificate expiration date by adjusting the date below DECLARE @cert_expiry_date AS varchar(max)='03/30/2025' -- Build the query to generate the certificate DECLARE @sqlserver_certificate_name NVARCHAR(MAX) = N'Cert_' + @@servername + N'_endpoint' DECLARE @sqlserver_certificate_subject NVARCHAR(MAX) = N'Certificate for ' + @sqlserver_certificate_name DECLARE @create_sqlserver_certificate_command NVARCHAR(MAX) = N'CREATE CERTIFICATE [' + @sqlserver_certificate_name + '] ' + char (13) + ' WITH SUBJECT = ''' + @sqlserver_certificate_subject + ''',' + char (13) + ' EXPIRY_DATE = '''+ @cert_expiry_date + ''''+ char (13) IF NOT EXISTS (SELECT name from sys.certificates WHERE name = @sqlserver_certificate_name) BEGIN PRINT (@create_sqlserver_certificate_command) -- Execute the query to create SQL Server certificate for the instance link EXEC sp_executesql @stmt = @create_sqlserver_certificate_command END ELSE PRINT 'Certificate ' + @sqlserver_certificate_name + ' already exists.' GO Import AG certificate public keys to SQL Managed Instance The public keys of the AG certificates need to be imported into the SQL Managed Instance. The below query will return the data required for the next step. -- Run on SQL Server -- Show the name and the public key of generated SQL Server certificate USE MASTER GO DECLARE @sqlserver_certificate_name NVARCHAR(MAX) = N'Cert_' + @@servername + N'_endpoint' DECLARE @PUBLICKEYENC VARBINARY(MAX) = CERTENCODED(CERT_ID(@sqlserver_certificate_name)); SELECT @sqlserver_certificate_name as 'SQLServerCertName' SELECT @PUBLICKEYENC AS SQLServerPublicKey; Example result The next step will need to be run in PowerShell and can be run through Azure Cloud Shell. Below is an example script to log in to Azure. # Run in Azure Cloud Shell (select PowerShell console) # Enter your Azure subscription ID $SubscriptionID = "<subscriptionid>" # Login to Azure and select subscription ID if ((Get-AzContext ) -eq $null) { echo "Logging to Azure subscription" Login-AzAccount } Select-AzSubscription -SubscriptionName $SubscriptionID Replace the values of $CertificateName, $PublicKeyEncoded and $ManagedInstanceName and then run this. # Run in Azure Cloud Shell (select PowerShell console) # =============================================================================== # POWERSHELL SCRIPT TO IMPORT SQL SERVER PUBLIC CERTIFICATE TO SQL MANAGED INSTANCE # ===== Enter user variables here ==== # Enter the name for the server SQLServerCertName certificate – for example, "Cert_sqlserver1_endpoint" $CertificateName = "<sqlservercertname>" # Insert the certificate public key blob that you got from SQL Server – for example, "0x1234567..." $PublicKeyEncoded = "<sqlserverpublickey>" # Enter your managed instance short name – for example, "sqlmi" $ManagedInstanceName = "<managedinstancename>" # ==== Do not customize the below cmdlets==== # Find out the resource group name $ResourceGroup = (Get-AzSqlInstance -InstanceName $ManagedInstanceName).ResourceGroupName # Upload the public key of the authentication certificate from SQL Server to Azure. New-AzSqlInstanceServerTrustCertificate -ResourceGroupName $ResourceGroup -InstanceName $ManagedInstanceName -Name $CertificateName -PublicKey $PublicKeyEncoded Repeat this step for all AG node values. Import the certificate public key of SQL Managed Instance to AG nodes Using the same PowerShell session, run this script to get the public key of the SQL Managed Instance certificate, replacing the value of the variable $ManagedInstanceName. # Run in Azure Cloud Shell (select PowerShell console) # =============================================================================== # POWERSHELL SCRIPT TO EXPORT MANAGED INSTANCE PUBLIC CERTIFICATE # ===== Enter user variables here ==== # Enter your managed instance short name – for example, "sqlmi" $ManagedInstanceName = "<managedinstancename>" # ==== Do not customize the following cmdlet ==== # Find out the resource group name $ResourceGroup = (Get-AzSqlInstance -InstanceName $ManagedInstanceName).ResourceGroupName # Fetch the public key of the authentication certificate from Managed Instance. Outputs a binary key in the property PublicKey. Get-AzSqlInstanceEndpointCertificate -ResourceGroupName $ResourceGroup -InstanceName $ManagedInstanceName -EndpointType "DATABASE_MIRRORING" | out-string</managedinstancename> On all nodes of the AG run the following query, replacing the certificate name and the value of the PublicKey with the output from the previous step. -- Run on SQL Server USE MASTER CREATE CERTIFICATE [<managedinstancefqdn>] FROM BINARY = <publickey></publickey></managedinstancefqdn> Import Azure-trusted root certificate authority keys to AG nodes Use the steps here to import the Microsoft PKI root-authority certificate and DigiCert PKI root-authority certificate onto all nodes of the AG. Alter the mirroring endpoint on AG nodes The mirroring endpoint on the AG nodes will also need to be updated to allow the Managed Instance to authenticate with the AG using the newly created certificate. This can be done by navigating to Server Objects > Endpoints > Database Mirroring. Right click on the endpoint and select Script Endpoint as > CREATE To > New Query Editor Window. Change CREATE ENDPOINT to ALTER ENDPOINT and add this command after AUTHENTICATION = WINDOWS NEGOTIATE CERTIFICATE, changing the cert_name value. CERTIFICATE [cert_name] Once updated, execute the query. For multiple Availability groups on the same instance, the next section would need to be repeated for each one. Create a distributed availability group on the AG (running against the primary server) Use this script to set up the distributed availability group, updating the sections in angle brackets (<>). The SQLServerIP will need to be the IP of the listener of the availability group. -- Run on SQL Server -- Create a distributed availability group for the availability group and database -- ManagedInstanceName example: 'sqlmi1' -- ManagedInstanceFQDN example: 'sqlmi1.73d19f36a420a.database.windows.net' USE MASTER CREATE AVAILABILITY GROUP [<dagname>] WITH (DISTRIBUTED) AVAILABILITY GROUP ON N'<agnameonsqlserver>' WITH ( LISTENER_URL = 'TCP://<sqlserverip>:<endpointport>', AVAILABILITY_MODE = ASYNCHRONOUS_COMMIT, FAILOVER_MODE = MANUAL, SEEDING_MODE = AUTOMATIC, SESSION_TIMEOUT = 20 ), N'<agnameonsqlmi>' WITH ( LISTENER_URL = 'tcp://<managedinstancefqdn>:5022;Server=[<managedinstancename>]', AVAILABILITY_MODE = ASYNCHRONOUS_COMMIT, FAILOVER_MODE = MANUAL, SEEDING_MODE = AUTOMATIC ); GO</managedinstancename></managedinstancefqdn></agnameonsqlmi></endpointport></sqlserverip></agnameonsqlserver></dagname> Set up the managed Instance Link The final step is to set up the link, the script for this is here. Please ensure that the $SQLServerIP is the IP of the AG listener and not the IP of the primary node. Once this is executed, the MI Link should be up and running and failing over to another node on the AG will not stop MI Link from syncing. Disclaimer Please note that products and options presented in this article are subject to change. This article reflects MI Link and the documentation in September 2025. I hope this article was helpful for you, please feel free to share your feedback in the comments section.SQL MI Restore with valid SAS key failing with Operating System Error 86
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Why do some databases show the restore point and why for few databases it shows “no restore point available”? Here is the scenario: Day 1 - > Geo-Replication/ Failover group setup, Primary in North Europe and Secondary in West Europe, PITR backup retention is set to 7 days. Day 2 -> Customer initiated failover, now Primary is in West Europe and secondary is in North Europe Day 4 -> Customer would like to restore the database to the state of Day1 which is possible as 7 days retention was set to PITR backups, and Day1 is 3 days back from current point in time As we are running backups only for the Primary DR, the new Primary in West Europe does not have the requested PITR backup (Day 1) The needed backup is “visible” on the backups listed for current secondary in North Europe The customer cannot restore to requested PITR as The restore cannot be initiated on the secondary as this is not possible for Secondary DR. The restore cannot be initiated on the primary as the backup is not there. Also, sometimes you will be seeing available PITR backups on Failover secondary server databases and for some databases it shows as “No restore point available” For the databases where the restore point is available, they can’t be able to restore it. The restore cannot be initiated on the secondary as this is not possible for Secondary DR. The restore cannot be initiated on the primary as the backup is not there. Clarifications In case the database was recently created, the first full backup might be still in the queue, so it might be a promising idea that you wait for some time before checking again. Failover groups is a disaster recovery feature that allows our customers to recover multiple related databases in a secondary region, after a catastrophic failure or other unplanned event that results in full or partial loss of service’s availability in the primary region. Database backups are an essential part of any business continuity and disaster recovery strategy because they protect your data from accidental corruption or deletion. It is important for us to understand that we are not losing any backups, in case the current region was not the primary at the desired point in time where your restoring point is holding, we will need to failover to the other region and make it as Primary, then you should be able to restore it. Backups are only taken on the Primary server, there can be several justifications why we can see PitR on some DBs and not for others on the Secondary Server. For the Databases that have PitR it is most probably because there was a failover that caused the Primary to become Secondary, as we have already had backups taken on the old primary which is secondary now. The DBs that do not have PitR They could have been provisioned after the last failover happened, so the backups are only available on the primary server Or they were added to the failover group after the last failover that will also cause the backups to be taken on the primary It should be fair to say that we will likely “fail back” once availability is restored in the original primary region because we might have picked that region for a reason. Note: - In case no geo-failover happened nor the database was recently created, and you still see “no restore point available,” please contact Microsoft support. Alternatives: you can perform Export operation on the secondary and import it on Primary DR. You can leverage geo redundant backup and Geo-restore, taking into consideration that Geo-restore is the most basic disaster-recovery solution available in SQL Database and SQL MI. It relies on automatically created geo-replicated backups with a recovery point objective (RPO) up to 1 hour and an estimated recovery time of up to 12 hours. Note: Azure SQL Managed Instance does not currently support exporting a database to a BACPAC file using the Azure portal or Azure PowerShell. To export a managed instance into a BACPAC file, use SQL Server Management Studio (SSMS) or SQLPackage. References: Restore a database from a backup - Azure SQL Database & SQL Managed Instance | Microsoft Docs Automatic, geo-redundant backups - Azure SQL Database & Azure SQL Managed Instance | Microsoft Docs Azure SQL Database Point in Time Restore | Azure Blog and Updates | Microsoft Azure Azure SQL Database Geo-Restore | Azure Blog and Updates | Microsoft Azure Disclaimer Please note that the products and options presented in this article are subject to change. This article reflects the database backup options available for Azure SQL database and Azure SQL managed instance in June 2022. 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