Folks, I am running a three-node 11i/RAC (11.5.9/9.2.0.6) environment in the lab and the following string exists in the DBC file: url="jdbc:oracle:thin@(DESCRIPTION=(LOAD_BALANCE=YES)(FAILOVER=YES)(ADDR ESS_LIST=(ADDRESS=(PROTOCOL=tcp)(HOST=MC0300UX550.apps.mc.xerox.com)(POR T=1604))(ADDRESS=(PROTOCOL=tcp)(HOST=MC0300UX194.apps.mc.xerox.com)(PORT =1604))(ADDRESS=(PROTOCOL=tcp)(HOST=MC0300UX551.apps.mc.xerox.com)(PORT= 1604)))(CONNECT_DATA=(SERVICE_NAME=e52rac)))" However, when a developer hard codes this string in the jsp (for test purpose) then it does not work. Also, I have the following entry in the tnsnames.ora file for both 806 and iAS: e52rac_BALANCE= (DESCRIPTION= (LOAD_BALANCE=YES) (FAILOVER=YES) (ADDRESS_LIST= (ADDRESS=(PROTOCOL=tcp)(HOST=MC0300UX550.apps.mc.xerox.com)(PORT=1604)) (ADDRESS=(PROTOCOL=tcp)(HOST=MC0300UX194.apps.mc.xerox.com)(PORT=1604)) (ADDRESS=(PROTOCOL=tcp)(HOST=MC0300UX551.apps.mc.xerox.com)(PORT=1604)) ) (CONNECT_DATA= (SERVICE_NAME=e52rac) ) ) And I can make connections to SQL*plus without any issue using the above service name. However, if I use the following syntax than it does not work from the middle-tier but it does work from the database tier. sqlplus system/<passwd>@(DESCRIPTION=(LOAD_BALANCE=YES)(FAILOVER=YES)(ADDRESS_LI ST=\ (ADDRESS=(PROTOCOL=tcp)(HOST=MC0300UX550.apps.mc.xerox.com)(PORT=1604))\ (ADDRESS=(PROTOCOL=tcp)(HOST=MC0300UX194.apps.mc.xerox.com)(PORT=1604))\ (ADDRESS=(PROTOCOL=tcp)(HOST=MC0300UX551.apps.mc.xerox.com)(PORT=1604))\ )(CONNECT_DATA=(SERVICE_NAME=e52rac))) After setting environment where ORACLE_HOME=8.0.6.3 SQL*Plus: Release 8.0.6.0.0 - Production on Wed Dec 14 14:41:08 2005 (c) Copyright 1999 Oracle Corporation. All rights reserved. ERROR: ORA-12154: TNS:could not resolve service name Enter user-name: After setting the iAS environment where ORACLE_HOME=8.1.7.0.0 SQL*Plus: Release 8.1.7.0.0 - Production on Wed Dec 14 14:42:02 2005 (c) Copyright 2000 Oracle Corporation. All rights reserved. SP2-0306: Invalid option. Usage: CONN[ECT] [logon] [AS {SYSDBA|SYSOPER}] | [INTERNAL] where <logon> ::= <username>[/<password>][@<connect_string>] | / Enter user-name: Any idea why the string works from the backend and not from the middle-tier. If the argument is that the ORACLE_HOME on the backend is 9.2.0.6 versus 8.0.6.3 and 8.1.7.0.0 on the middle tier then the 11i APPS on the middle-tier also uses the same service name as mentioned above and it works fine Thanks Amir