How many servers can consul handle? 10.000 - possible? 100.000?
I have an idea to implement configuration management system using it, and it is going to be a lot of nodes.
There is no hard upper limit, as James Phillips has answered here:
As long as your servers can handle the read/write loads you should be fine with thousands of agents. We have folks in the 10's of thousands of agents territory in a single datacenter.