RE: Any way to run more than listener on the same port?

  • From: "Adams, Matthew (GE Consumer & Industrial)" <MATT.ADAMS@xxxxxx>
  • To: <JayMiller@xxxxxxxxxxxxxxxx>, <oracle-l@xxxxxxxxxxxxx>
  • Date: Mon, 21 Mar 2005 14:11:16 -0500

This actually can work real nice if set up correctly.

The following discussion is relevant to HP and may or=20
may not apply the architecture you are using.

On hp, when using service guard for clustering, units of=20
work called packages are allowed to failover between servers.

Each package has a distinct name and IP address.  When you are running
many packages on a server (each with their own set of databases),
you can either have a single listener
that listens all the time for DBs that on that server (dynamicall =
and de-registering as they enter or leave a particular cluster)  or
you can set up a listener for each package, which listens on the IP =
of the package, not the IP address of the server.  All of these =
can listen on port 1521 for their own IP address with interfering with =
each other

There is one VERY important caveat to this.  If you are running =
idividual listeners
on the IP address of the packages, you CANNOT run an additional listener =
that listens
on the server IP address.  I'm not sure how it works under the covers, =
but it=20
appears that if you run a listener configured to listen on the IP =
address of the=20
server, it does a 'lanscan' or something equivalent, finds out all the =
IP address
being served by the machine (even the package IP address) and will start =
listener to=20
port 1521 on EVERY ip address served by the machine.  This interferes =
with the package
specific listeners.

This behavior was observed on 8.1.7 and 9.2.0

Therefore, you limit the listeners to ONLY listening on package address =
and not on
the server address.  This means, essentially, that all databases have to =
be in
a package and have their own listener (at least if they are going to be =
a machine in an HP service guard cluster)

-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx]On Behalf Of
Sent: Monday, March 21, 2005 1:18 PM
To: oracle-l@xxxxxxxxxxxxx
Subject: Any way to run more than listener on the same port?


For portability reasons our Unix SAs would like us to run one listener /
instance on the same port of each server.

While I have no problem setting up one listener for two instances or two
listeners on different ports I had been under the impression (born out =
preliminary experimentation) that you couldn't have more than one =
on the same port.

The Unix SAs say that since they've set up separate Virtual IP Addresses =
each instance we should be able to get it to work.

Anyone have any experience with this?  Is it possible?

Jay Miller


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