My go to setup if I need more uptime that a single server running in google cloud with live migration grants, is a three node galera cluster, with an A-record p

My go to setup if I need more uptime that a single server running in google cloud with live migration grants, is a three node galera cluster, with an A-record pointing to each node, which also runs the application in addition to the database. You can do rolling updates without any downtime, and I've even had setups like this go years without downtime. It isn't perfect but it works very well and obviates having to worry about things like stand-by switchover.