If you get the following error in your java+jsp+oracle application, then you probably need to increase your maximum session/process limits (Default process and sessions limit in Oracle 9i are 150 and 170 respectively) java.lang.Exception: SQL Error : java.sql.SQLException: Io exception: Connection refused(DESCRIPTION=(TMP=) Instructions for Increasing session, process and open_cursors max limits to 500 each are: [...]