Re: Not to use SCAN in 11gR2 RAC

From: Dan Norris <>
Date: Fri, 16 Oct 2009 12:09:50 -0700
Message-Id: <>

I would be careful about disabling or stopping it. Not necessarily because doing so will break anything, but more for patches, upgrades, or the potential that a future release may make it mandatory and then you'd have to figure out how to recreate and/or re-enable them.

As the SCAN listeners have relatively low system requirements, I would leave them there. I haven't seen official notes on it, though they may exist. This is just my opinion.


Typos included courtesy of large thumbs.

On Oct 16, 2009, at 11:59 AM, Yong Huang <> wrote:

> We installed RAC on a RHEL 5.3 two-node cluster
> successfully. It looks like SCAN (Single Client Access Name) must be
> assigned during installation.
> We have a company-wide OID to serve DB connection strings for
> thousands of clients. Each entry has load_balance=yes. It works very
> well. We're OK with continuing to use long strings (i.e. multiple
> address lines for each OID entry). Therefore we don't think SCAN
> provides benefit for our environment. Can anybody think of any risk
> or loss of benefit we haven't thought of? Is there any way to
> completely bypass it, not even bothering our DNS admin to create an
> entry (one or three A records)? If not during installation, can I
> stop the SCAN listener and shutdown its network interface (if I can)
> and remove it from OCR?
> Oracle says SCAN is optional unless you use policy-managed database
> in 11gR2. But it actually becomes mandatory at the time of
> installation, and then it can be optional afterward. Isn't that
> awkward?
> Yong Huang
> --

Received on Fri Oct 16 2009 - 14:09:50 CDT

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