After continuous google for more than 10 hours, I finally came to a conclusion that the problem “ORA-24408: could not generate unique server group name” was not with oracle instanclient or the connection string oci_connect(). The only problem was with the mis-match of the hostnames of the application server defined in /etc/sysconfig/network & /etc/hosts.
After modifying the hostnames in both the file to a single name, the problem was solved.
$ vi /etc/sysconfig/network NETWORKING=yes HOSTNAME=RHEL65 $vi /etc/hosts $ vi /etc/hosts #127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 127.0.0.1 RHEL65 $service network restart
The above steps helped me save my valuable time. Thanks to the bloggers.
I hope these information would help you too. Best wishes!