Using Distributed AGs for Your Migrations Elizabeth Noble Using Distributed AGs for Your Migrations

Using Distributed AGs for Your Migrations Elizabeth Noble Using Distributed AGs for Your Migrations Talk about use case

About Me e: elizabeth.a.noble@outlook.com t: @sqlzelda

Migrate to a Data Center

Migrate Across Domains https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/domain-independent-availability-groups?view=sql-server-2017

Data Center Migration Issues Need to sync data across multiple domains Need to sync data across long distances Need short cutover windows

What Can Distributed Availability Groups Do for Me? Synchronize across zero or more domains Synchronize across zero or more Windows Server Failover Clusters (WSFC) Synchronize across operating systems

Terminology First Availability Group Primary Node – Global Primary Secondary Node – Secondary Second Availability Group Primary Node – Forwarder

Create Availability Group Asynchronous https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Create Distributed AG on First AG

Create Distributed AG on Second AG

Create Distributed AG https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Manual Seeding Databases Add database to AG 2 Forwarder Add database AG 2 Secondary

Create Distributed AG Asynchronous https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Building the Distributed Availability Group Asynchronous https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Building the Distributed Availability Group Asynchronous https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Building the Distributed Availability Group https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Building the Distributed Availability Group Asynchronous https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Demo: Creation

Monitoring DMVs sys.availability_groups sys.availability_replicas sys.dm_hadr_availability_replica_states sys.dm_os_performance_counters Instance_nameLIKE ‘%<distributed AG name>%’ sys.dm_hadr_automatic_seeding

Monitoring Useful for troubleshooting synchronization errors current_state–FAILED Forwarder SQL Server log will show that seeding worked with the LSNs synchronized current_state–COMPLETED

Preparing for the Migration Must be a manual failover Stop all data traffic to the Global Primary

Update Availability Mode Set the Availability Mode to Synchronous on the Global Primary

Update Availability Mode Synchronous https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Verify Synchronization Get final LSN on first Availability Group Confirm LSN on second Availability Group matches

Update First Availability Group Change the first Availability Group to a secondary

Update First Availability Group X https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Failover with Data Loss On the Forwarder alter availability group to allow data loss

Failover with Data Loss Synchronous https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Update Availability Mode Set the Availability Mode back to Asynchronous on the new Global Primary

Update Availability Mode Asynchronous https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Failover Post-migration Rename the listener Update application to use new listener

Manual Failover to Second Availability Group Asynchronous https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Manual Failover to Second Availability Group Synchronous https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Manual Failover to Second Availability Group X https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Manual Failover to Second Availability Group https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Manual Failover to Second Availability Group Synchronous https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Manual Failover to Second Availability Group Asynchronous https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Manual Failover to Second Availability Group https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Manual Failover to Second Availability Group https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Demo: Failover

Removing Distributed AG Use T-SQL DROP AVAILABILITY GROUP <distributed AG name>

Migrating to the New Data Center Asynchronous https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Migrating to the New Data Center Asynchronous https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Migrating to the New Data Center https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Migrating to the New Data Center Asynchronous https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Migrating to the New Data Center Synchronous https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Migrating to the New Data Center X https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Migrating to the New Data Center https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Migrating to the New Data Center Synchronous https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Migrating to the New Data Center Asynchronous https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Migrating to the New Data Center https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Migrating to the New Data Center https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/distributed-availability-groups?view=sql-server-2017

Conclusion

Additional Resources https://www.sqlskills.com/blogs/jonathan/configuring-a-multi-subnet-sql-server-test-environment/ http://www.mikefal.net/2015/03/10/building-availability-groups-withpowershell/

Additional Resources https://docs.microsoft.com/en-us/sql/database-engine/availabilitygroups/windows/distributed-availability-groups?view=sql-server-2017 https://docs.microsoft.com/en-us/sql/database-engine/availabilitygroups/windows/configure-distributed-availability-groups?view=sql-server2017

Additional Resources https://docs.microsoft.com/en-us/sql/database-engine/availabilitygroups/windows/domain-independent-availability-groups?view=sql-server2017#create-a-domain-independent-availability-group https://docs.microsoft.com/en-us/sql/linux/sql-server-linux-availabilitygroup-overview?view=sql-server-2017#interoperability-with-windowsbased-availability-groups-and-replicas

Special Thanks