How to troubleshoot slow response from MySQL

[Jesper Petersen]

Hello

I have a MySQL server (v5.1.44-community) running on a Windows Server 2003 server with 4GB memory. The server is a dedicated MySQL server running nothing else than the SQL server.

Recently the server has become very slow in respoding to new TCP connections.

I've been capturing the network traffic between one of our webservers and the SQL server. After the web server has created the TCP connection with the SQL server more than 10 seconds pass before the SQL server responds with its "hello".
After that the web server can log in and do its query. The login procedure and the query is executed within a few milliseconds, so that is not an issue.

Do you have any good ideas as to why the SQL server is so long to respond to a new connection or how I can troubleshoot it? The server is not under any heavy load at all; CPU is always below 5%.

I have very little experience with SQL servers in general.

The server has not been updated in any way (drivers, etc.) - only Windows security updates.

Let me know if you need any other information.

Best regards
Jesper



Edited 2 time(s). Last edit at 04/12/2011 02:03PM by Jesper Petersen.