Patching your SQL Clusters is no problem unless you have a Windows Server 2012 cluster with SQL Server Always On availability groups.then you can’t use CAU the #NNFW (next next finish way) For Cluster.They said their production environment was down for more than 9 hours while they worked with Microsoft to resolve the issue. And restarting the instance underneath the primary replica with no failover is exactly the type of thing we expect High Availability to save us from. It had an issue that impacted some installs where processes named would keep running and use tons of CPU. It was pretty nasty, and it raised the issue, “Should you trust Service Packs?” (Spoiler: no.) That issue wasn’t specific to AGs. It was dangerous advice to follow, because Service Packs are released very slowly these days. They’re incredibly smart, very dedicated, super helpful, and they work very hard to make a great product.
So I placed the scripts on the CSV from my Cluster Disclaimer: Microsoft does not support the use of CAU to update Windows Server 2012 clusters with SQL Server Always On availability groups.
If you don’t have at least an hour a week to keep on top of available fixes, and another eight hours a month (minimum) to devote to testing and deploying fixes, you don’t have time for an AG. When I’m not figuring out the solutions to your database problems, you’ll find me at user group meetings in Portland, Oregon.
Cluster Aware Updating or CAU is a great tool for patching your cluster but there are some situations that you need to be carefully when using CAU.
Greetings, Robert Smit https://robertsmit.wordpress.com/?
Have you ever wanted to disable Cluster Aware Updating perhaps just for a while or even permanently?
Search for cluster aware updating:
If you apply these updates, you may run into a critical blocking issue which you can only fix by: Update: KB 3033492 has now been published which gives more information on options to avoid the issue (spoiler: it requires an outage), or other ways you can attempt to correct it by killing sessions (which may not work). There’s a chance that the issue might be detected after your planned patching window has ended (and you’ve gone back to sleep), and then you’ve got an unplanned downtime on your hand and unhappy customers. Proactively take the steps above when applying patches to prevent the bug from occurring.