Configure both peers in availability groups

Article
09/25/2024

Beginning with SQL Server 2019 (15.x) CU 13 a database that belongs to a SQL Server Always On availability group can participate as a peer in a peer-to-peer transactional replication topology. This article describes how to configure this scenario with two peers - each in its own availability group.

The scripts in this example use T-SQL stored procedures.

Roles & names

This section describes the roles and names of the various elements participating in the replication topology for this article.

Peer1

Node1: Primary replica for first availability group
Node2: Secondary replica for first availability group
MyAG: Availability group name for first availability group
MyDBName: Peer1 database. Database to be published
Dist1: Remote distributor
P2P_MyDBName: Publication name
MyAGListenerName: Availability group listener

Peer2

Node3: Primary replica for second availability group
Node4: Secondary replica for second availability group
MyAG2: Availability group name for second availability group name
MyDBName: Database to be published
Dist2: Remote distributor
P2P_MyDBName: Publication name
MyAG2ListenerName: Availability group listener

Prerequisites

Four instances of SQL Server on separate physical or virtual servers to host the availability groups. Two availability groups each contain a peer database.
Two instances of SQL Server to host the distributor databases.
All server instances require a supported edition - Enterprise edition or Developer edition.
All server instances require a supported version - SQL Server 2019 (15.x) CU13 or later.
Sufficient network connectivity and bandwidth between all instances.
Install SQL Server replication on all instances of SQL Server.

To see if replication is installed on any instance, run the following query:
```
USE master;   
GO   
DECLARE @installed int;   
EXEC @installed = sys.sp_MS_replication_installed;   
SELECT @installed; 
```
Note

To avoid a single point of failure for the distribution database, use a remote distributor for each peer.

For demonstration or test environment, you may configure the distribution databases on a single instance.

Configure the distributor and remote publisher (Peer1)

This section describes how to set up the first peer (Peer1) in an availability group.

Run sp_adddistributor to configure distribution on Dist1. Use @password = to specify a password that the remote publisher uses to connect to the distributor. Use this password at each remote publisher when you configure the remote distributor.
```
USE master;  
GO  
EXEC sys.sp_adddistributor  
 @distributor = 'Dist1',  
 @password = '<Strong password for distributor>';  
```

Create the distribution database at the distributor.

USE master;
GO  
EXEC sys.sp_adddistributiondb  
 @database = 'distribution',  
 @security_mode = 1;

Configure Node1 and Node2 remote publisher.

The @security_mode determines how the replication agents connect to the current primary.
- 1 = Windows authentication.
- 0 = SQL Server authentication. Requires @login and @password. The login and password specified must be valid at each secondary replica.
Note

If any modified replication agents run on a computer other than the distributor, use of Windows authentication for the connection to the primary requires Kerberos authentication to for the communication between the replica host computers. Use of a SQL Server login for the connection to the current primary doesn't require Kerberos authentication.
```
USE master;  
GO  
EXEC sys.sp_adddistpublisher  
 @publisher = 'Node1',  
 @distribution_db = 'distribution',  
 @working_directory = '\\MyReplShare\WorkingDir',  
 @security_mode = 1
USE master;  
GO  
EXEC sys.sp_adddistpublisher  
 @publisher = 'Node2',  
 @distribution_db = 'distribution',  
 @working_directory = '\\MyReplShare\WorkingDir',  
 @security_mode = 1
```

Configure the publisher at the original publisher (Node1)

Configure remote distribution original publisher (Node1). Specify the same value for @password as that used when sp_adddistributor was run at the distributor to set up distribution.
```
EXEC sys.sp_adddistributor  
@distributor = 'Dist1',  
@password = '<Password used when running sp_adddistributor on distributor server>' 
```

Enable the database for replication.

USE master;  
GO  
EXEC sys.sp_replicationdboption  
 @dbname = 'MyDBName',  
 @optname = 'publish',  
 @value = 'true';

Configure the secondary replica host as replication publisher (Node2)

At each secondary replica host (Node2) for the first availability group, configure distribution. Specify the same value for @password as that used when sp_adddistributor was run at the distributor to set up distribution.

EXEC sys.sp_adddistributor  
   @distributor = 'Dist1',  
   @password = '<Password used when running sp_adddistributor on distributor server>'

Make the database part of the availability group and create the listener (Peer1)

On the intended primary replica, create the availability group with the database as a member database.
Create a DNS listener for the availability group. The replication agent connects to the current primary replica by using the listener. The following example creates a listener named MyAGListenerName.
```
ALTER AVAILABILITY GROUP 'MyAG'
ADD LISTENER 'MyAGListenerName' (WITH IP (('<ip address>', '<subnet mask>') [, PORT = <listener_port>]));   
```
Note

In the script above, information in square brackets ([ ... ]) is optional. Use it to specify a non default value for TCP port. Do not include the brackets.

Redirect the original publisher to the AG listener name (Peer1)

On the distributor for Peer1, redirect the original publisher to the AG listener name.

USE distribution;   
GO   
EXEC sys.sp_redirect_publisher    
@original_publisher = 'Node1',   
@publisher_db = 'MyDBName',   
@redirected_publisher = 'MyAGListenerName,<port>';

Note

In the script above ,<port> is optional. It is only required if you are using non-default ports. Do not include then angle brackets <>.

Create peer-to-peer publication (Peer1) on the original publisher - Node1

The following script creates the publication for Peer1.

EXEC master..sp_replicationdboption  @dbname=  'MyDBName'   
        ,@optname=  'publish'   
        ,@value=  'true'  
GO
DECLARE @publisher_security_mode smallint = 1
EXEC [MyDBName].dbo.sp_addlogreader_agent @publisher_security_mode = @publisher_security_mode
GO
DECLARE @allow_dts nvarchar(5) = N'false'
DECLARE @allow_pull nvarchar(5) = N'true'
DECLARE @allow_push nvarchar(5) = N'true'
DECLARE @description nvarchar(255) = N'Peer-to-Peer publication of database MyDBName from Node1'
DECLARE @enabled_for_p2p nvarchar(5) = N'true'
DECLARE @independent_agent nvarchar(5) = N'true'
DECLARE @p2p_conflictdetection nvarchar(5) = N'true'
DECLARE @p2p_originator_id int = 100
DECLARE @publication nvarchar(256) = N'P2P_MyDBName'
DECLARE @repl_freq nvarchar(10) = N'continuous'
DECLARE @restricted nvarchar(10) = N'false'
DECLARE @status nvarchar(8) = N'active'
DECLARE @sync_method nvarchar(40) = N'NATIVE'
EXEC [MyDBName].dbo.sp_addpublication @allow_dts = @allow_dts, @allow_pull = @allow_pull, @allow_push = @allow_push, @description = @description, @enabled_for_p2p = @enabled_for_p2p, @independent_agent = @independent_agent, @p2p_conflictdetection = @p2p_conflictdetection, @p2p_originator_id = @p2p_originator_id, @publication = @publication, @repl_freq = @repl_freq, @restricted = @restricted, @status = @status, @sync_method = @sync_method
GO
DECLARE @article nvarchar(256) = N'tbl0'
DECLARE @description nvarchar(255) = N'Article for dbo.tbl0'
DECLARE @destination_table nvarchar(256) = N'tbl0'
DECLARE @publication nvarchar(256) = N'P2P_MyDBName'
DECLARE @source_object nvarchar(256) = N'tbl0'
DECLARE @source_owner nvarchar(256) = N'dbo'
DECLARE @type nvarchar(256) = N'logbased'
EXEC [MyDBName].dbo.sp_addarticle @article = @article, @description = @description, @destination_table = @destination_table, @publication = @publication, @source_object = @source_object, @source_owner = @source_owner, @type = @type
GO
DECLARE @article nvarchar(256) = N'tbl1'
DECLARE @description nvarchar(255) = N'Article for dbo.tbl1'
DECLARE @destination_table nvarchar(256) = N'tbl1'
DECLARE @publication nvarchar(256) = N'P2P_MyDBName'
DECLARE @source_object nvarchar(256) = N'tbl1'
DECLARE @source_owner nvarchar(256) = N'dbo'
DECLARE @type nvarchar(256) = N'logbased'
EXEC [MyDBName].dbo.sp_addarticle @article = @article, @description = @description, @destination_table = @destination_table, @publication = @publication, @source_object = @source_object, 
@source_owner = @source_owner, @type = @type
GO

Make peer to peer publication compatible with availability group (Peer1)

On original publisher (Node1), run the following script to make the publication compatible with availability group:

USE MyDBName
GO
DECLARE @publication sysname = N'P2P_MyDBName' 
DECLARE @property sysname = N'redirected_publisher' 
DECLARE @value sysname = N'MyAGListenerName,<port>' 
EXEC MyDBName..sp_changepublication @publication = @publication, @property = @property, @value = @value 
GO

Note

In the script above ,<port> is optional. It is only required if you are using non-default ports.

After you have completed the steps above, the availability group is prepared to participate in peer-to-peer topology. The next steps configure a separate availability group as the second peer (Peer2) in the peer-to-peer replication topology.

Configure the distributor and remote publisher (Peer2)

This section describes how to set up the second peer (Peer2) in a different availability group.

Run sp_adddistributor to configure distribution on Dist2. Use @password = to specify a password that the remote publisher uses to connect to the distributor. Use this password at each remote publisher when you configure the remote distributor.
```
USE master;  
GO  
EXEC sys.sp_adddistributor  
 @distributor = 'Dist2',  
 @password = '<Strong password for distributor>';  
```

Create the distribution database at the distributor.

USE master;
GO  
EXEC sys.sp_adddistributiondb  
 @database = 'distribution',  
 @security_mode = 1;

Configure Node3 and Node4 remote publisher.

The @security_mode determines how the replication agents connect to the current primary.
- 1 = Windows authentication.
- 0 = SQL Server authentication. Requires @login and @password. The login and password specified must be valid at each secondary replica.
Note

If any modified replication agents run on a computer other than the distributor, use of Windows authentication for the connection to the primary requires Kerberos authentication to for the communication between the replica host computers. Use of a SQL Server login for the connection to the current primary doesn't require Kerberos authentication.
```
USE master;  
GO  
EXEC sys.sp_adddistpublisher  
 @publisher = 'Node3',  
 @distribution_db = 'distribution',  
 @working_directory = '\\MyReplShare\WorkingDir2',  
 @security_mode = 1
USE master;  
GO  
EXEC sys.sp_adddistpublisher  
 @publisher = 'Node4',  
 @distribution_db = 'distribution',  
 @working_directory = '\\MyReplShare\WorkingDir2',  
 @security_mode = 1
```

Configure the publisher (Peer2)

Configure remote distribution on (Node3). Specify the same value for @password as that used when sp_adddistributor was run at the distributor to set up distribution.
```
EXEC sys.sp_adddistributor  
@distributor = 'Dist2',  
@password = '<Password used when running sp_adddistributor on distributor server>' 
```

Enable the database for replication.

USE master;  
GO  
EXEC sys.sp_replicationdboption  
 @dbname = 'MyDBName',  
 @optname = 'publish',  
 @value = 'true';

Configure the secondary replica host as replication publisher (Node4)

At each secondary replica host (Node4) for the second availability group, configure distribution. Specify the same value for @password as that used when sp_adddistributor was run at the distributor to set up distribution.

EXEC sys.sp_adddistributor  
   @distributor = 'Dist2',  
   @password = '<Password used when running sp_adddistributor on distributor server>'

Make the database part of the availability group and create the listener (Peer2)

On the intended primary replica, create the availability group with the database as a member database.
Create a DNS listener for the availability group. The replication agent connects to the current primary replica by using the listener. The following example creates a listener named MyAG2ListenerName.
```
ALTER AVAILABILITY GROUP 'MyAG2'
ADD LISTENER 'MyAG2ListenerName' (WITH IP (('<ip address>', '<subnet mask>') [, PORT = <listener_port>]));   
```
Note

In the script above, information in square brackets ([ ... ]) is optional. Use it to specify a non default value for TCP port. Do not include the brackets.

Redirect the original publisher to the AG listener name (Peer2)

On the distributor for Peer2, redirect the original publisher to the AG listener name.

USE distribution;   
GO   
EXEC sys.sp_redirect_publisher    
@original_publisher = 'Node3',   
@publisher_db = 'MyDBName',   
@redirected_publisher = 'MyAG2ListenerName,<port>';

Note

In the script above ,<port> is optional. It is only required if you are using non-default ports. Do not include then angle brackets <>.

Create peer-to-peer publication (Peer2)

The following script creates the publication for Peer2.

On Node3 run the following command to create the peer-to-peer publication.

EXEC master..sp_replicationdboption  @dbname=  'MyDBName'   
        ,@optname=  'publish'   
        ,@value=  'true'  
GO
DECLARE @publisher_security_mode smallint = 1
EXEC [MyDBName].dbo.sp_addlogreader_agent @publisher_security_mode = @publisher_security_mode
GO

-- Note – Make sure that the value for @p2p_originator_id is different from Peer1.
DECLARE @allow_dts nvarchar(5) = N'false'
DECLARE @allow_pull nvarchar(5) = N'true'
DECLARE @allow_push nvarchar(5) = N'true'
DECLARE @description nvarchar(255) = N'Peer-to-Peer publication of database MyDBName from Node3'
DECLARE @enabled_for_p2p nvarchar(5) = N'true'
DECLARE @independent_agent nvarchar(5) = N'true'
DECLARE @p2p_conflictdetection nvarchar(5) = N'true'
DECLARE @p2p_originator_id int = 1
DECLARE @publication nvarchar(256) = N'P2P_MyDBName'
DECLARE @repl_freq nvarchar(10) = N'continuous'
DECLARE @restricted nvarchar(10) = N'false'
DECLARE @status nvarchar(8) = N'active'
DECLARE @sync_method nvarchar(40) = N'NATIVE'
EXEC [MyDBName].dbo.sp_addpublication @allow_dts = @allow_dts, @allow_pull = @allow_pull, @allow_push = @allow_push, @description = @description, @enabled_for_p2p = @enabled_for_p2p, @independent_agent = @independent_agent, @p2p_conflictdetection = @p2p_conflictdetection, @p2p_originator_id = @p2p_originator_id, @publication = @publication, @repl_freq = @repl_freq, @restricted = @restricted, @status = @status, @sync_method = @sync_method
GO
DECLARE @article nvarchar(256) = N'tbl0'
DECLARE @description nvarchar(255) = N'Article for dbo.tbl0'
DECLARE @destination_table nvarchar(256) = N'tbl0'
DECLARE @publication nvarchar(256) = N'P2P_MyDBName'
DECLARE @source_object nvarchar(256) = N'tbl0'
DECLARE @source_owner nvarchar(256) = N'dbo'
DECLARE @type nvarchar(256) = N'logbased'
EXEC [MyDBName].dbo.sp_addarticle @article = @article, @description = @description, @destination_table = @destination_table, @publication = @publication, @source_object = @source_object, @source_owner = @source_owner, @type = @type
GO

DECLARE @article nvarchar(256) = N'tbl1'
DECLARE @description nvarchar(255) = N'Article for dbo.tbl1'
DECLARE @destination_table nvarchar(256) = N'tbl1'
DECLARE @publication nvarchar(256) = N'P2P_MyDBName'
DECLARE @source_object nvarchar(256) = N'tbl1'
DECLARE @source_owner nvarchar(256) = N'dbo'
DECLARE @type nvarchar(256) = N'logbased'
EXEC [MyDBName].dbo.sp_addarticle @article = @article, @description = @description, @destination_table = @destination_table, @publication = @publication, @source_object = @source_object, 
@source_owner = @source_owner, @type = @type
GO

Make peer to peer publication compatible with availability group (Peer2)

On the original publisher (Node3), run the following script to make the publication compatible with availability group:

USE MyDBName
GO
DECLARE @publication sysname = N'P2P_MyDBName' 
DECLARE @property sysname = N'redirected_publisher' 
DECLARE @value sysname = N'MyAG2ListenerName,<port>' 
EXEC MyDBName..sp_changepublication @publication = @publication, @property = @property, @value = @value 
GO

Note

In the script above ,<port> is optional. It is only required if you are using non-default ports.

Create a push subscription from Peer1 to the availability group listener for Peer2

To create a push subscription from Peer1 to the availability group listener Peer2, run the following command on Node1.

Execute the following script on Node1. This assumes Node1 is running the primary replica.

Important

The script below specifies the availability group listener name for the subscriber.

@subscriber = N'MyAGListenerName,<port>'

Note

In the script above ,<port> is optional. It is only required if you are using non-default ports. Do not include then angle brackets <>.

EXEC [MyDBName].dbo.sp_addsubscription 
   @publication = N'P2P_MyDBName'
 , @subscriber = N'MyAG2Listener,<port>' 
 , @destination_db = N'MyDBName'
 , @subscription_type = N'push'
 , @sync_type = N'replication support only'
GO

EXEC [MyDBName].dbo.sp_addpushsubscription_agent 
   @publication = N'P2P_MyDBName'
 , @subscriber = N'MyAG2Listener,<port>' 
 , @subscriber_db = N'MyDBName'
 , @job_login = null 
 , @job_password = null
 , @subscriber_security_mode = 1
 , @frequency_type = 64
 , @frequency_interval = 1
 , @frequency_relative_interval = 1
 , @frequency_recurrence_factor = 0
 , @frequency_subday = 4
 , @frequency_subday_interval = 5
 , @active_start_time_of_day = 0
 , @active_end_time_of_day = 235959
 , @active_start_date = 0
 , @active_end_date = 0
 , @dts_package_location = N'Distributor'
GO

Create a push subscription from Peer2 to the availability group listener (Peer1)

To create a push subscription from Peer2 to the availability group listener (Peer1), run the following command on Node3.

Important

The script below specifies the availability group listener name for the subscriber.

@subscriber = N'MyAGListenerName,<port>'

Note

In the script above ,<port> is optional. It is only required if you are using non-default ports. Do not include then angle brackets <>.

EXEC [MyDBName].dbo.sp_addsubscription 
   @publication = N'P2P_MyDBName'
 , @subscriber = N'MyAGListenerName,<port>'
 , @destination_db = N'MyDBName'
 , @subscription_type = N'push'
 , @sync_type = N'replication support only'
GO

EXEC [MyDBName].dbo.sp_addpushsubscription_agent 
   @publication = N'P2P_MyDBName'
 , @subscriber = N'MyAGListenerName,<port>'
 , @subscriber_db = N'MyDBName'
 , @job_login = null
 , @job_password = null
 , @subscriber_security_mode = 1
 , @frequency_type = 64
 , @frequency_interval = 1
 , @frequency_relative_interval = 1
 , @frequency_recurrence_factor = 0
 , @frequency_subday = 4
 , @frequency_subday_interval = 5
 , @active_start_time_of_day = 0
 , @active_end_time_of_day = 235959
 , @active_start_date = 0
 , @active_end_date = 0
 , @dts_package_location = N'Distributor'
GO

Configure linked servers

At each secondary replica host, make sure the push subscribers of the database publications appear as linked servers.

EXEC sys.sp_addlinkedserver   
    @server = 'MySubscriber';

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Configure both peers in availability groups

Roles & names

Peer1

Peer2

Prerequisites

Configure the distributor and remote publisher (Peer1)

Configure the publisher at the original publisher (Node1)

Configure the secondary replica host as replication publisher (Node2)

Make the database part of the availability group and create the listener (Peer1)

Redirect the original publisher to the AG listener name (Peer1)

Create peer-to-peer publication (Peer1) on the original publisher - Node1

Make peer to peer publication compatible with availability group (Peer1)

Configure the distributor and remote publisher (Peer2)

Configure the publisher (Peer2)

Configure the secondary replica host as replication publisher (Node4)

Make the database part of the availability group and create the listener (Peer2)

Redirect the original publisher to the AG listener name (Peer2)

Create peer-to-peer publication (Peer2)

Make peer to peer publication compatible with availability group (Peer2)

Create a push subscription from Peer1 to the availability group listener for Peer2

Create a push subscription from Peer2 to the availability group listener (Peer1)

Configure linked servers

Next steps

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