RE: RAC One Node - Instances not open at the same time!

Did I miss a memo and service connection node preference is not available on “One Node?”  

My initial reaction is that having one or the other node as preferred and then restarting the service the opposite if a node is intentionally down would be a reasonable solution that, for example, allows non-application work to reside in the instance shared pool and possibly buffer cache of the non-preferred instance.  

Your mileage may vary.  

mwf  

From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Martin Klier - Performing Databases GmbH Sent: Tuesday, July 04, 2017 5:24 AM
To: Ethan Post
Cc: Martin Berger; Oracle-L oracle-l
Subject: Re: RAC One Node - Instances not open at the same time!  

Ethan,  

thank you very much.

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Martin Klier | Performing Databases GmbH Managing Partner | Senior DB Consultant
Oracle ACE

martin.klier_at_performing-db.com | https://www.performing-databases.com  

Von: "Ethan Post" <post.ethan_at_gmail.com> An: "martin klier" <martin.klier_at_performing-db.com>, "Martin Berger" <martin.a.berger_at_gmail.com> CC: "Oracle-L oracle-l" <oracle-l_at_freelists.org> Gesendet: Montag, 3. Juli 2017 16:22:22
Betreff: RE: RAC One Node - Instances not open at the same time!

2 cents  

My recommendation would be to set up an alert that opens ticket, sends email/message etc…when two instances are running with an explanation of the reasons both should not be open unless the potential for problems is truly high risk issue.  

The “trigger” solution is good but if you are in a high turnover environment, moving to cloud someday, cloning, replicating system, doing upgrades etc…there is a chance this will come back to bite someone someday. It isn’t obvious enough, whereas the alert would be very obvious.  

So if you have big data/job corruption issue then it needs to be enforced strictly, otherwise go with an notify solution.  

Thanks  

From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Martin Klier - Performing Databases GmbH Sent: Monday, July 3, 2017 5:53 AM
To: Martin Berger <martin.a.berger_at_gmail.com> Cc: Oracle-L oracle-l <oracle-l_at_freelists.org> Subject: Re: RAC One Node - Instances not open at the same time!  

Martin,  

sounds very cool. Thanks!  

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Martin Klier | Performing Databases GmbH Managing Partner | Senior DB Consultant
Oracle ACE

martin.klier_at_performing-db.com | https://www.performing-databases.com  

Von: "Martin Berger" <martin.a.berger_at_gmail.com> An: "Martin Klier" <martin.klier_at_performing-db.com> CC: "Oracle-L oracle-l" <oracle-l_at_freelists.org> Gesendet: Freitag, 30. Juni 2017 14:32:00 Betreff: Re: RAC One Node - Instances not open at the same time!

Hi Martin,

as this is an open discussion what's about this concept:  

you write a startup trigger which immediately set

alter system enable restricted session;

then it spools gv$instance until it's sure the other instance is gone,

at the end do

alter system disable restricted session;  

that's maybe not a very elegant method, but it might solve your request?  

(everything is untested right now on my side)  

Martin  

2017-06-30 13:22 GMT+02:00 Martin Klier - Performing Databases GmbH <martin.klier_at_performing-db.com>:

Why? It's an open concept discussion, no system was configured yet.

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Martin Klier | Performing Databases GmbH Managing Partner | Senior DB Consultant
Oracle ACE

martin.klier_at_performing-db.com | https://www.performing-databases.com  

Von: "Mladen Gogala" <gogala.mladen_at_gmail.com> An: oracle-l_at_freelists.org
Gesendet: Freitag, 30. Juni 2017 00:21:30 Betreff: Re: RAC One Node - Instances not open at the same time!

On 06/29/2017 07:24 AM, Martin Klier - Performing Databases GmbH wrote:

Hi Listers,  

when running Oracle RAC One Node, is there a way to avoid both instances being open at the same time?  

Background:

I have an application that's by no way ready for RAC (using dbms_jobs and much more). But they want to use the benefits of One Node for operating the cluster. All that's needed is a failover cluster.  

Please post the output of srvctl config db -d <DB name>.

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Mladen Gogala
Oracle DBA
Tel: (347) 321-1217          

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