We have a mysql server working on Ubuntu server.
Many clients (using a Windows Xp app) give us the "Lost connection to MySQL server during query".
How can I track down the problem?
The server is always fully functional and I don't have any diagnostic idea. The server is sitting on a VmWare ESXi and has always worked perfectly.
Use icpld from http://icpld.northernmost.org
ICPLD is a connection monitor which allows you to keep track of your network connection perfomance. It will log each occasion of broken networking. It runs as a background process, and sends ICMP requests to an ip of your choice. When a reply isn't received within proper amount of time, it will consider the connection as unavailable and put a stamp in its log.
You could look in /var/log/mysql.* /var/log/mysql/error.log to see if your server has anything to say about daytime activities.
You could also come up with a simple MySQL transaction that you could run periodically to check response time.
You could adapt this answer to maintain connectivity
