When setting up the MySQL probe using a "SOCKET" connection type, the probe defaults to looking in /tmp/ for the mysql.sock file. When attempting to change the location as in the following screenshot:
An error will be observed indicating that the specified location is not being used, but /tmp/mysql.sock is used instead:
mysql probe 1.51 or prior
SOCKET connection type
mysql.sock not located in /tmp
There is a hotfix available (mysql-1.5.1-HF1 or higher) which can be obtained from the UIM Hotfix Index Site
This will be resolved in the next GA version of the mysql probe past 1.51.