I have asked this question at the MySQL Forums website, but it has not yet had a reply, so I thought I'd try here. It's purely MySQL related though I'm afraid. You can see my post at MySQL here.

The question is this :

I am trying to understand exactly what defines a 'concurrent connection'. I understand it means multiple connections to the MySQL database, but between what and to what? A user, a website, a server, several servers, several websites? For example, say a single website has a MySQL backend...If there are 20 users of the website in any particular time, is that 20 'concurrent connections' to the MySQL database? Or, is the website itself linking to the SQL server just 1 'concurrent connection' regadless of how many users are using the site? So you'd have to have say 10 sites accessing the same SQL server to have 10 concurrent connections? So if there were say 10 websites running on the same MySQL database, that would be 10 concurrent connections even if each of the 10 website had, say, 100 users each at the same time?

Can anyone help me understand this?

Thanks

Ted

Short rule (if "persistent connections" disabled)
1 client - 1 connection from forked apache process to MySQL backend.
With persistent connection situation is ligtly different
- 1 Connection established and never closed for 1 client IP, not client connection