Re: Flashback guaranteed restore point with ADG for DB upgrade fallback

From: Karthikeyan Panchanathan <keyantech_at_gmail.com>
Date: Wed, 10 Oct 2018 21:15:54 -0400
Message-Id: <B93303F4-3BD3-4ED5-9D0B-5D5F5056C5DD_at_gmail.com>



We use same way as explained by Joe here.

Make GRP on standby once broke replication with Primary. Then create GRP on Primary.

Keep in mind you need lot of space for FRA and archive-logs in Standby.

We always make sure Primary keep sending log to Standby but never apply.

When Primary passed all validation we enable replication else flashback.

HTH
Karth

Sent from my IPhone

> On Oct 10, 2018, at 2:11 PM, Jose Rodriguez <jrodriguez2_at_pythian.com> wrote:
> 
> I've recently used the exact same approach for an ADG upgrade. This was 11.2.0.3 to 11.2.0.4, but the idea is the same.
> As Niall says, just enable flashback database on both sides, create a GRP on the standby first and then on the primary, so you have an older SCN on the standby in case of a rollback.
> Bear in mind the required FRA space for the flashback logs, not much for the upgrade itself, but this will be recording the applied redo on the standby as well if I recall correctly.
> I tested it and it worked like a charm.
> I am not at my desk right now, so I can't share any docs, but I'll take a look tomorrow.
> 
>> On Wed, 10 Oct 2018, 20:03 , <niall.litchfield_at_gmail.com> wrote:
>> I'll try and look it up when I get back but I think we went with a GRP on both sides, then flashback independently.  
>> 

>>> On Wed, 10 Oct 2018, 17:31 Rich J, <rjoralist3_at_society.servebeer.com> wrote:
>>> Hey all,
>>>
>>> I've been working on a plan to get our databases upgraded from 11.2.0.3 to 12.1.0.2. Most of the planning is relatively straightforward, except for one DB. It has active data guard to a physical standby. I've managed to work out how to properly upgrade it, despite the "instructions" at https://docs.oracle.com/database/121/SBYDB/upgrades.htm#SBYDB4931
>>>
>>> The part I can't figure out is how to rollback the upgrade in a timely manner, should it be needed. The easiest is to restore from backup and recreate the standby, but that will take several hours. https://mikedietrichde.com/2017/08/29/fallback-strategy-flashback-to-guaranteed-restore-points/ says to use Flashback guaranteed restore points, but there's no mention of how this should work with a standby. No problem, I can figure that out. The restore point on the primary doesn't exist on the standby, but I can get the SCN, subtract 2 (as per MOS articles), then FLASHBACK STANDBY DATABASE TO SCN nnnn. That produces "ORA-38726: Flashback database logging is not on.", since, well, flashback isn't on. It's not needed for the primary -- is that a restriction on the standby?
>>>
>>> Anyone know 1) where this might be documented, and 2) how one might go about planning a time-sensitive upgrade fallback for an ADG setup?
>>>
>>> I was thinking that instead of relying on the SCN for the Flashback on the standby that maybe I'd need to setup a separate guaranteed restore point (with MRP stopped) before the primary one is created. I've been testing various scenarios, but as it takes >30 minutes to set up each scenario, I thought I should ask here to possibly save me a couple of days of fun.
>>>
>>> Thanks!
>>> Rich
>>>
> 
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Received on Thu Oct 11 2018 - 03:15:54 CEST

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