Hello,

What Amazon EC2 instance size would be needed to support 100,00 concurrent users?

There is no machine that can serve that quantity alone. You need a fleet. As soon as you use a fleet, you need a central fileserver to store user data. Currently CS has direct support for using Postgres in that role.  And Postgres can also be sharded into a fleet when you get enough usage for that need.

Bruce Wilcox - Jun 10, 2016:

There is no machine that can serve that quantity alone. You need a fleet. As soon as you use a fleet, you need a central fileserver to store user data. Currently CS has direct support for using Postgres in that role.  And Postgres can also be sharded into a fleet when you get enough usage for that need.

Thank you very much for the reply, Bruce. How many servers would constitute the fleet? or perhaps put another way, how many users can a server within a fleet handle?

It depends on how complex your chatbot is, what it does for computation. Rose, our lead Loebner bot, nominally takes under 10ms on a cheap processor. So it can handle 100 users per second, but users take time, so a 10 second volley speed per user would mean 1000 users per second being handled.