Work is a little busy at the moment, but I had time to look at this a bit more today …
Many thanks for the useful follow-up comments on the last posting. They were very interesting and if I’d picked them up in some of my Google searches, we might have solved the problem more quickly, although I would re-emphasise a couple of general points :-
1) This particular problem is nothing to do with RAC, in as much as the server concerned is not part of a cluster, so this is just as likely to happen on a single instance/node.
2) What’s irritating about this is that it’s because the Listener is configured to use ONS by default, even if we’re unlikely to be interested in using it in a single-instance environment. (Actually, is that true? I’ll come back to that.)
What I neglected to mention last time is that there is another work-around mentioned in the various Metalink notes. We can rename the ons.config file so that the Listener won’t see it and try to start ONS. This is from my server at home.
Sun Microsystems Inc. SunOS 5.10 Generic January 2005 $ cd $ORACLE_HOME/opmn/conf $ ls -ltra total 6 drwxr-x--- 7 oracle oinstall 512 Oct 7 2006 .. -rw------- 1 oracle oinstall 44 Oct 7 2006 ons.config drwx------ 2 oracle oinstall 512 Oct 7 2006 . $ cat ons.config localport=6100 remoteport=6200 loglevel=3
So I could just rename ons.config and restart the Listener and that should fix it.
However, I much prefer the original solution I mentioned. Rather than renaming configuration files in the ORACLE_HOME with no obvious reason why (which seems a bit of a hack to me), I prefer having the parameter in listener.ora which explicitly disables the subscription, with a comment explaining why it’s there. e.g.
# Workaround for bug 4518443 - should be fixed in 10.2.0.3 SUBSCRIBE_FOR_NODE_DOWN_EVENT_LISTENER=OFF
Better still, just patch to the right level, but we found the listener change less risky and faster to implement. It went in last night although I’m glad to say it wasn’t me that made the change – thanks Richard 😉
Oh, yes, so why do Oracle configure this even in a non-RAC environment? Well, for all I know it’s just a mistake, but it occurred to me that just because it’s single-instance and it might not be so useful, maybe an application would want to use FAN? Maybe not.