On the Zenoss server ensure your device has the Mysql zenpack
On the mysql server you plan to monitor do the following;
Add a user to Mysql so that zenoss can connect.
mysql -u root -p
grant ALL PRIVILEGES ON *.* TO ‘zenoss’@'yourzenossdomain’ IDENTIFIED BY ‘yourpassword’;
Don’t forget to open port 3306 on the firewall of the Mysql server if necessary.
On the Zenoss server add the mysql user and password to zproperties of the device.
If Mysql version <5> 5
You can test that your monitored server can authenticate from your Zenoss server by
mysql -u zenoss -p -h yourmonitoredserverip
credit to http://www.how-to-linux.com