So, what i want to do is related with sql patching (This pertains to normal sql patching - CU's/SP's in the same sql version)
Can patching be done say on prod AG nodes on one weekend , apps test on it on the next week, if all is fine , update the BCP AG nodes on next weekend - The reason i want to do this is if there is a issue reported by apps after the initial prod patching we have a env (bcp) where we can failover till the issue is resolved in Prod.
My question is - Is it possible to failover sql from a patched prod to unpatched bcp if needed, is that possible in AG?
And secondly, how are people going about patching their AG env's , please don't answer about rolling upgrades ,this is not about minimizing downtime(https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/upgrading-always-on-availability-group-replica-instances?view=sql-server-2017) , I am only interested in knowing if people are looking into patching only 1 env first and waiting for some time & then patching other.
Maybe i am going about it a wrong way, do people uninstall the CU's , SP's if issues and just do the complete prod-bcp patching together - is that the best way?
Thanks
D