Assumptions
This post discusses the procedure for upgrading a two node always on cluster. The latest SQL Server updates can be found here.
It is assumed Node1 is initially the primary and Node2 is the secondary.
The same procedure can be used for Windows Update, Service Packs, Cumulative Updates and GDRs.
Prerequisite Checks
- Do a practice failover backward and forward to make sure the failover works.
- Go to Node1.
- Expand “AlwaysOn High Availability > Availability Groups”.
- Right-click on the Availability Group and pick the “Failover” menu option.
- Work through the wizard until the failover is complete.
- Repeat on Node2 (the new primary) to fail back to Node1 (the original primary).
- Check you have good backups.
- Run DBCC CHECKDB on every database on the primary and check for errors.
Patch Procedure
Node1 : Prevent automatic failover.
- Expand “AlwaysOn High Availability > Availability Groups”
- Right click on the Availability Group and pick the “Properties” menu option.
- Set the failover mode for both nodes to “Manual”.
- Click the “OK” button.
Node2 :
- Install the latest Service Pack and the latest Cumulative Update (CU) or GDR.
- Reboot as required.
Node1 :
- Check synchronization is OK. You can see this listed against the databases.
- Failover to Node2, making Node1 the secondary.
Node1 :
- Install the latest Service Pack and the latest Cumulative Update (CU) or GDR.
- Reboot as required.
Node2 :
- Check synchronization is OK. You can see this listed against the databases.
- Failover to Node1, making Node2 the secondary.
Node1 : Enable automatic failover.
- Expand “AlwaysOn High Availability > Availability Groups”
- Right click on the Availability Group and pick the “Properties” menu option.
- Set the failover mode for both nodes to “Automatic”.
- Click the “OK” button.
The procedure is now complete.
For more information see: