Citrix has done a good job in helping us make a XenApp or XenDesktop environment based on provisioning high available.
Once your target devices are up, you’re mostly in the green zone:
- A target device that has acquired license has a grace period.
- Offline database support allows your SQL server to take a break.
- 2 or more provisioning servers ensure high availability for your target devices.
- NIC teaming
- And so on…
However, when your target devices go into a (scheduled) reboot, you can go into the red zone.