How to Apply Windows (OS) Patches or Hotfixes in a Tertiary Configuration With Minimal Interruption

How to Apply Windows (OS) Patches or Hotfixes in a Tertiary Configuration With Minimal Interruption

Summary

This article can be used to apply operating system (OS) patches or hotfixes on a Neverfail Continuity Engine server group in a Tertiary configuration with minimal interruption.

More Information

Neverfail's unique architecture allows you to install updates to the operating system or apply hotfixes without interrupting end-users. The active/passive/passive server group allows you to install the update or hotfix on one server and ensure functionality before installing on the others. See the instructions below on how to install an update or hotfix.

If your server group is configured as a Neverfail Pair, see KB article - How to Apply Windows (OS) Patches or Hotfixes in a Pair Configuration With Minimal Interruption 

Procedure

Before implementing this procedure, ensure that the Automatic Update feature supplied by Microsoft is configured so that Updates are NOT applied automatically.  It is acceptable to allow the updates to be downloaded automatically.

Note: The procedure assumes that Neverfail Continuity Engine is configured with the Primary server as active and both the File System Status and Registry Status are synchronized.

Important:

If you have Microsoft products protected by Continuity Engine (i.e. SQL Server, Exchange, IIS Server, etc.) do not allow them to be updated automatically by Windows Update, while Engine is replicating: the risk is to have configuration changes replicated while actual binaries are not. And this may cause application inconsistency on the standby passive servers. (Engine doesn't replicate application binaries; it replicates only app config and data). Thus, do not check Give me updates for other Microsoft products when I update Windows.

Patching a Neverfail Continuity Engine Tertiary Server Group Without Management (backdoor) IP Addresses

  1. On the Primary (active) server, launch Windows Update.
  2. Download and install the patches or hotfixes, but DO NOT restart the server if instructed to do so.
  3. Launch the Neverfail Advanced Management Client.
  4. Perform a switchover using the Neverfail Advanced Management Client to make the Secondary server active.

    Note: At this point users may notice a slight interruption to the protected application. 
  5. Wait for switchover to complete. If a restart was not required at step 2, go to step 11.
  6. Shutdown Neverfail Continuity Engine on all three servers (Primary, Secondary, and Tertiary) selecting the option to Shutdown Group - Leave protected applications running.
  7. Restart the Primary server to complete the installation of the OS patches or hotfixes.
  8. Verify all patches and hotfixes are installed properly. 
  9. Start Neverfail Continuity Engine on the Secondary and Tertiary servers and on the Primary server if Neverfail Continuity Engine did not start automatically after the restart.
  10. Allow servers to connect and synchronize with the Secondary as active and the Primary and Tertiary as passive. Once synchronization has completed, proceed with the next step.
  11. Launch the Windows Update on the Secondary (active) server.
  12. Download and install the patches or hotfixes, but DO NOT restart the server if instructed to do so.
  13. Launch the Neverfail Advanced Management Client.
  14. Perform a switchover using the Neverfail Management Client to make the Tertiary server active. 

    Note: At this point users may notice a slight interruption to the protected application. 
  15. Wait for switchover to complete. If a restart was not required at step 12, go to step 21.
  16. Shutdown Neverfail Continuity Engine on all three servers by selecting the option to Shutdown Group - Leave protected applications running.
  17. Restart the Secondary server to complete the install of the OS patches or hotfixes.
  18. Verify all patches are installed properly.
  19. Start Neverfail Continuity Engine on the Primary and Tertiary servers and on the Secondary server if Neverfail Continuity Engine did not start automatically after the server restart.
  20. Allow servers to connect and synchronise with the Tertiary as active and the Secondary and Primary as passive. Once synchronisation has completed, proceed to the next step. 

    Note: At this point users may notice a slight interruption to the protected application.
  21. Launch Windows Update on the Tertiary (active) server.
  22. Download and install the patches or hotfixes, but DO NOT restart the server if instructed to do so.
  23. Launch the Neverfail Advanced Management Client.  
  24. Perform a switchover using the Neverfail Advanced Management Client to make the Primary server active. 

    Note: At this point users may notice a slight interruption to the protected application. 
  25. Wait for switchover to complete. If a restart was not required at step 22, go to step 31. 
  26. Shutdown Neverfail Continuity Engine on all three servers by selecting the option to Shutdown Group - Leave protected applications running.
  27. Restart the Tertiary server to complete the installation of the OS patches or hotfixes.
  28. Verify all patches are installed properly. 
  29. Start Neverfail Continuity Engine on the Primary and Secondary servers and on the Tertiary server if it did not start automatically after the server restart. 
  30. Allow servers to connect and synchronise with the Primary as active and the Secondary and Tertiary as passive. Once synchronisation has completed, proceed to the next step. 
  31. On the Primary (active) server, launch Windows Update again and check for any further updates that may be required.  If additional updates are required, repeat steps 2 through 31. 


 Applies To

Neverfail Continuity Engine

Related Information

None 

KBID-2959