Distributed systems bring their own problems. I've seen more production outages caused by poorly coded or configured HA setups than due to any single-host level

Distributed systems bring their own problems. I've seen more production outages caused by poorly coded or configured HA setups than due to any single-host level hardware failure. I remember one application where a 60 second network outage caused a forty minute database outage due to HA supervisors going batshit. What works well are simple setups like async log shipping to another site with manual fail-over. If you think you cannot afford 30 minutes downtime there is really no amount of money you can spend to be sure you are improving your chances.