When I clicked on PING in the GF admin console, I get this warning:
WARNING: RAR8054: Exception while creating an unpooled [test] connection for pool [ mydb_pool ], Unknown command
I can see most the MySQL system variables in ConnectionPool>AdditionalProperties tab. So, I believe the driver is visible to GF.
[Message sent by forum member 'arthury']
http://forums.java.net/jive/thread.jspa?messageID=483558