Is it possible to upgrade cf platform with 100% uptime for apps.

Let me give you an scenario of the platform:

1 haproxy
2 instances for gorouter, health manager
3 VMs for dea instances
1 instance for cloud controller ng, postgres, uaa etc.
1 for nfs server
1 for cc worker
1 for doppler
1 for logtraffic controller



My answer is no, because when haproxy is down, you can't connect to the
apps.

What is the right strategy for 100% uptime for apps?

Ben