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

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

3. About Me e:

4. Migrate to a Data Center

5. Migrate Across Domains

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

7. 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

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

9. Create Availability Group
Asynchronous

10. Create Distributed AG on First AG

11. Create Distributed AG on Second AG

12. Create Distributed AG

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

14. Create Distributed AG Asynchronous

15. Building the Distributed Availability Group
Asynchronous

16. Building the Distributed Availability Group
Asynchronous

17. Building the Distributed Availability Group

18. Building the Distributed Availability Group
Asynchronous

19. Demo: Creation

20. 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

21. 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

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

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

24. Update Availability Mode
Synchronous

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

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

27. Update First Availability GroupX

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

29. Failover with Data Loss
Synchronous

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

31. Update Availability Mode
Asynchronous

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

33. Manual Failover to Second Availability Group
Asynchronous

34. Manual Failover to Second Availability Group
Synchronous

35. Manual Failover to Second Availability GroupX

36. Manual Failover to Second Availability Group

37. Manual Failover to Second Availability Group
Synchronous

38. Manual Failover to Second Availability Group
Asynchronous

39. Manual Failover to Second Availability Group

40. Manual Failover to Second Availability Group

41. Demo: Failover

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

43. Migrating to the New Data Center
Asynchronous

44. Migrating to the New Data Center
Asynchronous

45. Migrating to the New Data Center

46. Migrating to the New Data Center
Asynchronous

47. Migrating to the New Data Center
Synchronous

48. Migrating to the New Data CenterX

49. Migrating to the New Data Center

50. Migrating to the New Data Center
Synchronous

51. Migrating to the New Data Center
Asynchronous

52. Migrating to the New Data Center

53. Migrating to the New Data Center

54. Conclusion

55. Additional Resources

56. Additional Resources

57. Additional Resources

58. Special Thanks