Cause: Database was upgraded to Oracle 11g in which passwords are case sensitive while in 10g passwords were not case sensitive.
The issue was because we were having 10g ODP.NET at our BAM machine instead of 11g. Whenever we send the passwords using 10g ODP.NET ,it converts them into all upper cases and send it to 11g DB thus resulting in "ORA-1017: invalid username/password; logon denied" error when we try to start active data cache service.
Resolution: There are multiple resolutions for this issue
1. Upgrade ODP.NET to 11g
2. Change the password such that each character is in upper case
3. Set SEC_CASE_SENSITIVE_LOGON to FALSE so that on 11g database password become insensitive
