Set Display setting at OS startup(xhost + ....)

[imkonsultant]

Version R12/11i? = 11i
Instance PROD/TEST/VIS? = PROD
Module? = ALL
OS? = Red Hat Linux

i would like to discuiss some issue regarding "Chapter 13:Display Setting" of Oracle Application 11i/12i Admini Ver 4.0.

I have tested these setting at test instance at my side and its works fine for single instance(Applications and Database tier on same system), my question is what to do if we have multi node system. DISPLAY="localhost:0.0" could be set in .bash_profile on both nodes but where to set "xhost +" on DB node.

Another issue regarding VNC is that, after server reboot user automatically login to system and the above settings applied successfully, but I can not lock screen either remotely from vnc or directly by sitting infront of terminal, and this is very risky for production environment.