R12 login fails with FND_NO_DATABASE_CONNECTION

Error in Login in to HRMS apps R12.

Error Page:

Exception Details.
 oracle.apps.fnd.framework.OAException: Application: FND, Message Name: FND_NO_DATABASE_CONNECTION.
    at oracle.apps.fnd.framework.webui.OAPageErrorHandler.prepareException(OAPageErrorHandler.java:1251)
    at oracle.apps.fnd.framework.webui.OAPageBean.preparePage(OAPageBean.java:2195)
    ..........
## Detail 0 ##
oracle.apps.fnd.framework.OAException: Application: FND, Message Name: FND_NO_DATABASE_CONNECTION.
    at oracle.apps.fnd.framework.server.OANullDBTransactionImpl.noDatabaseConnection(OANullDBTransactionImpl.java:653)
    at oracle.apps.fnd.framework.server.OANullDBTransactionImpl.isLoggingEnabled(OANullDBTransactionImpl.java:930)
    at oracle.apps.fnd.framework.OASessionCookieHelper.resetApplicationModule(OASessionCookieHelper.java:201)
    at oracle.apps.fnd.framework.webui.OAHttpSessionCookieImpl.releaseApplicationModule(OAHttpSessionCookieImpl.java:551)
    .....
   
 
Work around:
Restart the application

cd $ADMIN_SCRIPTS_HOME
sh adstpall.sh
pkill -u <apps username> --> linux or kill all apps user process.
sh adstrtal.sh

For permenanet fix ref below metalink link and apply the patch.

R12: Login Fails Intermittently With Error "oracle.apps.fnd.framework.OAException: Application: FND, Message Name: FND_NO_DATABASE_CONNECTION" (Doc ID 1298103.1)