By default Yellowfin has a 5 minute connection timeout to the Yellowfin database.
Sometimes it is necessary to increase this, for example, you might be doing a import of a large export file that exceeds 5 minutes in which case the import will fail and there will be an error in the logs something to effect of "the connection object is closed".
All you have to do to increase the length of time before the connection times out is to add the JDBCTimeout parameter and value to the web.xml file (
You can read more about how JDBCTimeout works here.