Approx. 6,000 to 8,000 thin clients
Your thin clients are installed at several locations. In the morning, users switch them on manually. Some thin clients also run at night.
4 UMS servers + 2 load balancers on separate devices.
The devices will not boot at the same time - because they are switched on manually. Most of the requests will be distributed over a certain period of time, possibly 5-10 minutes.
During this period of time, the four UMS servers can process even more requests.