Today early morning I saw strange error on listener log. ... Mon Feb 09 07:53:24 2015 WARNING: Subscription for node down event still pending 09-FEB-2015 07:53:24 * (CONNECT_DATA=(CID=(PROGRAM=)(HOST=????)(USER=oracle))(COMMAND=status)(ARGUMENTS=64)(SERVICE=LISTENER)(VERSION=185599744)) * status * 0 ... After searching on metalink I found : MOS document with ID 372959.1 In a nutshell to fix it we should add SUBSCRIBE_FOR_NODE_DOWN_EVENT_YOURLISTENER_NAME=OFF on listener.ora file In my case: SUBSCRIBE_FOR_NODE_DOWN_EVENT_LISTENER=OFF Then restart/reload listener. lsnrctl reload;