[freefaler]

For your basic needs you'd need:

1. a DNS monitoring with failover (DNSMadeeasy has a decent solution)

2. a Haproxy setup with health checks for switching to a working upstream service

3. a distributed filesystem

4. a master-slave replication with monitoring (something like Mariadb + orchestrator service)

and nightly backups for all this. Database and FS are latency sensitive so they shouldn't be too far apart.