I would suggest doing some plain debugging on the database connection. I mean doing this debugging outside of concrete5.

I had a similar problem and found out that the internal DNS was very slow at resolving the name's IP but the actual connection was very fast when I switched to connecting with IP only. But it was just this case and it's impossible to say what's wrong in your case.

So, I'd suggest:
1. Writing few lines of PHP to test the connection and its speed
2. Testing to connect with straight IP address
3. Checking MySQL server logs possibly
4. Tracking the MySQL server to notice any performance issues

Also, if this happens only on some specific page, it might not be because of the connection but rather some un-optimized query running very long time.

Hope this helps!


Antti / Mainio

Thank you for your reply :)

All my other applications (non concrete5) work very quickly when connecting remotely to the MySQL database so I don't think it's a problem with the MySQL server.

Thanks

Ok, I guess your problem is not then with connecting to the database but somewhere else.

As said, it's tough to guess what's the problem without seeing it...