Re: listener - lsnrctl reload drops dynamic service handlers

"Peter" <no_email_at_no_email.com> wrote in message news:b4p9hu$juf$1_at_bunyip.cc.uq.edu.au...
> The documents that I quoted, specifically state that, "without actually
> stopping the listener" which is different to what you said which is,
> "Basically a reload is a stop followed by a start".
>
> I wish that the documents were more specific in that they don't state (or
I
> can't find) when the dynamic services will be registered after the reload
> command is issued

Check the documentation for the PMON process, because it's PMON that actually does the instance registration on a periodic basis (last time I checked, it was about every 5 minutes).

>- "...listener will be unregistered and subsequently
> registered again...". I had assumed that this would be straight away but I
> have found that this is not the case.
>
> With the ever increasing use of dynamic registration, I believe that the
> documentation is lacking, and could cause downtime, in that it should
state
> that dynamically reliant services could be unavailable for up to a minute
at
> a time (and I have found this to be longer when the listener is
experiencing
> high loads). Instead this is not mentioned at all.
>
> This brings me back to my original question, which is, does the lsnrctl
> reload command drop dynamic service handlers thus making dynamically
> registered databases unavailable for a certain period of time (a
supposedly
> maximum period of 1 minute)?

Er, sort of. Bear in mind that you can have dynamic registration happening (for the purposes of load-balancing) and yet still have databases statically declared (still required for Enterprise Manager, for example). So you might lose load-balancing capabilities for potentially up to 5 minutes (not sure where you're getting the 1 minute figure from), but connections would still be available during that time because of the static declarations.

Or you could migrate to 9i, where the command 'alter system register' forces re-registration at will.

(Incidentally, in case there was any doubt, the stopping and starting of a listener never means that existing connections are killed off, merely that new ones cannot be made for the duration. So the statement "This would of course result in wiping mts connections." would be wrong if "wiping" were to be taken to mean 'terminating").

Regards
HJR Received on Thu Mar 13 2003 - 10:45:14 CST