[weeno]

Originally Posted by Marco van Herwaarden

I am running (well doing tech. admin for) a board that each day has periods with over 2.000 concurrent users online. Still running it on a single machine (dedicated ofcourse), although it starts to hit the limits of a single machine. As i can still run it on a single machine, i consider it to be just a medium sized board.

I'm surprised you can run over 2000 concurrent users on a single machine. I guess you are running a relatively recent server. I feel like I had to move out of one server well before I hit 2000 concurrent users, but it was a few years ago I suppose, so older hardware.

Originally Posted by BrandiDup

And how exactly can you use two servers at once? You can't split up your forum between two different servers can you?

I think the progression is typically:

1 server for php + mysql, but if you start running into problems you would split the services into one php server and one mysql server, and tend to bulk up the mysql server with faster hard drives, more ram.

From there, I think you can do a number of things, depending on your bottlenecks.

Add a PHP Cache
Move all static files/images off the php server
Move attachments to a separate server
Use something besides Apache
Split the PHP server into multiple php servers

arn