Re: Extended RAC and multicast

From: Tim Gorman <tim_at_evdbt.com>
Date: Wed, 16 Apr 2014 09:36:25 -0600
Message-ID: <534EA379.2020502_at_evdbt.com>



Iggy,

Not to open any cans of worms (and please feel free to not answer this question for any reason), but why did they choose an "extended RAC" deployment in the first place, as opposed to any of the Data Guard options? Do they already use Data Guard? Was there something that "extended RAC" (or "geographically-dispersed cluster" technology) does better than Data Guard (or database replication technology) in general?

Just curious...

Thanks!

-Tim

On 4/16/2014 9:21 AM, Iggy Fernandez wrote:
> Thank you very much Martin.
>
> We found additional information on the multicast requirement at the
> following link:
>
> http://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/UCS_CVDs/cisco_ucs_oracle_rac.html#wp439295
>
> Kindest regards,
>
> Iggy
>
> --
> Iggy Fernandez
> Email: iggy_fernandez_at_hotmail.com <mailto:iggy_fernandez_at_hotmail.com>
> Cellphone: (925) 478 3161
> Blog: So Many Manuals So Little Time
> <http://iggyfernandez.wordpress.com/>
> Author of Beginning Oracle Database 11/g/ Administration
> <http://books.google.com/books?id=pdSLnG66WQkC&printsec=frontcover#v=onepage&q&f=false>
> Editor of the /NoCOUG Journal <http://bit.ly/rC2gRA>/
> Lecturer at University of Washington Professional and Continuing
> Education <http://www.pce.uw.edu/biography/ignatius-fernandez/>
>
>
> ------------------------------------------------------------------------
> From: martin.a.berger_at_gmail.com
> Date: Mon, 14 Apr 2014 20:46:39 +0200
> Subject: Re: FW: Extended RAC and multicast
> To: iggy_fernandez_at_hotmail.com
> CC: oracle-l_at_freelists.org; kulkarniravi_at_yahoo.com
>
> Iggy, Ravi,
> from all my test I call multicast a requirement from 11.2.0.2 onwards.
> Take care about the different Multicast networks possible in different
> Patch-Sets!
> As you are talking about VLAN_S_ - I'd not do anything than pure
> switched private network. Everything else will lead to troubles sooner
> or later.
>
> My .02
> Martin
>
>
> On Mon, Apr 14, 2014 at 8:29 PM, Iggy Fernandez
> <iggy_fernandez_at_hotmail.com <mailto:iggy_fernandez_at_hotmail.com>> wrote:
>
> A friend asked me a question that I could not answer. He is in the
> planning stages of an "extended RAC deployment" and is looking for
> confirmation that multicasting is optional.
>
> Help would be appreciated.
>
> Kindest regards,
>
> Iggy
>
> --
> Iggy Fernandez
> Email: iggy_fernandez_at_hotmail.com <mailto:iggy_fernandez_at_hotmail.com>
> Cellphone: (925) 478 3161
> Blog: So Many Manuals So Little Time
> <http://iggyfernandez.wordpress.com/>
> Author of Beginning Oracle Database 11/g/ Administration
> <http://books.google.com/books?id=pdSLnG66WQkC&printsec=frontcover#v=onepage&q&f=false>
> Editor of the /NoCOUG Journal <http://bit.ly/rC2gRA>/
> Lecturer at University of Washington Professional and Continuing
> Education <http://www.pce.uw.edu/biography/ignatius-fernandez/>
>
>
> ------------------------------------------------------------------------
> Date: Mon, 14 Apr 2014 11:13:03 -0700
> From: kulkarniravi_at_yahoo.com <mailto:kulkarniravi_at_yahoo.com>
> Subject: Extended RAC and multicast
> To: iggy_fernandez_at_hotmail.com <mailto:iggy_fernandez_at_hotmail.com>
>
> I am looking to setup extended RAC for my client. The details are
> as following:
>
> The two data centers are separated by a distance of less than 20
> miles.
>
> They are connected by a high speed dedicated connection.
>
> Operating System: RHEL 6 64 bit
>
> Database version: 11gR2 (11.2.0.3)
>
> Hardware: Four servers with 4x16 configuration
>
> All the documentation I have reviewed so far says multicast should
> be enabled on the private interconnect between all the nodes
> of a RAC database. However, my network resources tell me that
> multicasting is not enabled across the data centers and VLANs
> do not span across the data centers. The only reference I have
> seen to multicasting requirement is in this Oracle document:
>
> http://docs.oracle.com/cd/E16655_01/install.121/e17888/networks.htm#CWLIN476
>
> Specifically it makes the following assertion:
>
> "You do not need to enable multicast communications across routers"
>
> Does this mean, multicast is optional?
>
> Regards,
>
> Ravi Kulkarni
>
>

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Received on Wed Apr 16 2014 - 17:36:25 CEST

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