Load balancing of ADFS 2.0. How many users does stand-alone server support?

Question

I want to figure out how many users can ADFS 2.0 stand-alone server support. I mean load of the server. My customers said that it supports just 100 users (seems strange for a server and so simple operations) and they have 700 users at the same time. So he recomended to have a federation farm instead of stand-alone server. But I prefere to check first.

So, can you share info about load limitations of stand-alon SSO server VS server farms? Any docs, articles with numbers, experts ideas or so on...

Answer 1

We have standalone servers that support WAY more than 100 users - easily over 1000.

Not sure what the upper limit is?

A farm is only going to help if you have a load balancer in front of them

Answer 2

I also found an article about this problem. The auther writes that they use 2 ADFS servers for 10 000 users. And there is a calculator to get number of servers depending on the load and users

Answer 3

There is no such restriction and it solely depends on how often users login to your system.

We have few deployments of the adfs, one of them supports like 50000 users and only TWO servers are enough. I even suspect one would do however this is, as always, not a good idea to have just one server (at least two servers = failover, you wouldn't want the whole environment to be inaccessible just because your login server just died).

The idea would be then to start with two servers and monitor the infrastructure. Add other instances only when necessary.