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RE: Multiple Listeners

From: John Weatherman <>
Date: Wed, 16 Oct 2002 13:19:24 -0800
Message-ID: <>

-----Original Message-----
Sent: Wednesday, October 16, 2002 4:20 PM

A single listener and a single Intelligent Agent should be all that is needed. It may be clever to see if multiple listeners can run, but even Oracle will tell you that running multiple listeners is worse than foolish.:) In addition to changing the Oracle Home, the LD_LIBRARY_PATH or LIBPATH would have to be changed as well to match the libraries to the correct version of the listener.

-----New Stuff----

Yes, I cut a lot. :) I will agree that having 1 listener per box is all you _should_ need. However, due to experience with past bugs (and who knows

when similar problems may appear in the future) and as you concede, running high availability fail over services, I would disagree with the assertion that
multiple listeners are "worse than foolish". A single listener is a single point of failure across multiple instances, eliminating that is not foolish, and there are other reasons one might want to run multiple listeners. What about extproc (if you need it for some reason). Oracle itself _requires_ 3 listeners for the apps the last time I checked (1 for the db, 2 for external

program calls). To analyze network traffic, it is sometimes useful to be able
to isolate particular port traffic. Multiple listeners allow for this kind of work too.

So, while only 1 may be all that is necessary, there is no real reason, IMHO,
that multiple listeners are inherently a bad practice.

John P Weatherman
Database Administrator
Replacements Ltd.

Please see the official ORACLE-L FAQ:

Author: John Weatherman

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