Re: EM DG switchover across EM repositories?

  • From: Niall Litchfield <niall.litchfield@xxxxxxxxx>
  • To: Pete Sharman <pete.sharman@xxxxxxxxxx>
  • Date: Tue, 2 Jun 2015 10:42:35 +0100

HI Dave,

Is the question "Can I perform a switchover using DG Broker, and what will
that do to EM? " OR "Can I use EM to perform switchovers when the databases
are registered in 2 different repositories?"

The answer to the first is yes you can, and you'll likely find that your
targets are messed up! (but a quick fix would be to reset the monitoring
credentials on each of them). Courtney and Peter seem to have answered the
second one. We have targets across the US and in several EU locations.
EM12c sits in London and handles this all pretty well, but we don't have
the transatlantic bandwidth issues you describe (we of course have
latency).

On Tue, Jun 2, 2015 at 12:08 AM, Peter Sharman <pete.sharman@xxxxxxxxxx>
wrote:

Dave

One of the reasons the agent was completely rebuilt with 12c was because
of the restart issues you referred to below, so it might be worthwhile
investigating a migration to 12c as a longer term scenario.

Coming back to your question on the primary / standby config, the only way
EM can handle this for you is if both primary and standby are managed by
the same agents. As a single agent cannot communicate to multiple OMS's,
Courtney's original comment that this could not be done with multiple EM's
is correct - as I would expect. :)

Now, the other alternative is to have two agents monitoring each
database. I have seen that done - for example, when Platinum Services is
monitoring an environment and a customer still wants to monitor it as
well. However, that can get VERY messy very quickly (who responds to
alerts, who patches, etc. etc.) so I wouldn't advise that set up. Even in
that case, I'm not sure what you want can be done. It MIGHT be able to be
done that way, but I'd want to see some serious testing before I'd rely on
it, and as I say it would open a whole lot of other issues as well.

Pete

Pete Sharman
Database Architect, DBaaS / DBLM
Enterprise Manager Product Suite
33 Benson Crescent CALWELL ACT 2905 AUSTRALIA
Phone: +61262924095 | | Fax: +61262925183 | | Mobile: +61414443449
Email: pete.sharman@xxxxxxxxxx Twitter: @SharmanPete LinkedIn:
au.linkedin.com/in/petesharman
Website: petewhodidnottweet.com

"Controlling developers is like herding cats."
Kevin Loney, Oracle DBA Handbook

"Oh no, it's not, it's much harder than that!"
Bruce Pihlamae, long term Oracle DBA


-----Original Message-----
From: Herring, David [mailto:HerringD@xxxxxxx]
Sent: Tuesday, June 2, 2015 4:31 AM
To: Peter Sharman; oracle-l@xxxxxxxxxxxxx
Cc: Courtney Llamas
Subject: RE: EM DG switchover across EM repositories?

Sure, I'll check the link. My reasoning is that we have a number of
installations in both the UK and US, many with either OGG or DG
configured. The line between the 2 locations is limited and closely
monitored. We've had a few situations when loads have been heaviest on the
app side in terms of changes that log ships failed and for whatever reason
an automatic attempt wasn't made to retrieve the log so we had to do it
manually. This isn't the direct reason of why we have 2 different EMs but
more an example of line issues and why limiting traffic is so important. I
can make all the recommendations of why it's necessary to increase
bandwidth but I'm at the mercy of those who pay for it.

In addition to the above example, we have under 11g registered both UK and
US targets in an 11g EM in the UK. Unfortunately those US agents would
frequently require restarts due to communication problems. Maybe issues
like this are resolved under 12c and if so, great but my hope was to
eliminate as much as possible any trans-atlantic traffic as it related to
EM. Now if I can't avoid that when wanting full DG capabilities then I'll
accept that and continue with work-arounds as necessary.

Pete, do you know for sure that want I'm hoping for won't work, that both
primary and standby need to be in the same EM?

Regards,

Dave



Dave Herring
DBA
103 JFK Parkway
Short Hills, New Jersey 07078
Mobile 630.441.4404

dnb.com




-----Original Message-----
From: Peter Sharman [mailto:pete.sharman@xxxxxxxxxx]
Sent: Monday, June 01, 2015 1:16 PM
To: Herring, David; oracle-l@xxxxxxxxxxxxx
Cc: Courtney Llamas
Subject: RE: EM DG switchover across EM repositories?

Though the question should be asked, what's the reason for having two EM
repositories in the first place? There are valid reasons for doing that,
but more often than not the reasons people have it set up that way is often
a misunderstanding of EM capabilities. See
http://dbasushi.com/one-em-to-rule-them-all for a good coverage of that.

Pete

Pete Sharman
Database Architect, DBaaS / DBLM
Enterprise Manager Product Suite
33 Benson Crescent CALWELL ACT 2905 AUSTRALIA
Phone: +61262924095 | | Fax: +61262925183 | | Mobile: +61414443449
Email: pete.sharman@xxxxxxxxxx Twitter: @SharmanPete LinkedIn:
au.linkedin.com/in/petesharman
Website: petewhodidnottweet.com

"Controlling developers is like herding cats."
Kevin Loney, Oracle DBA Handbook

"Oh no, it's not, it's much harder than that!"
Bruce Pihlamae, long term Oracle DBA


-----Original Message-----
From: Courtney Llamas
Sent: Tuesday, June 2, 2015 3:03 AM
To: HerringD@xxxxxxx; oracle-l@xxxxxxxxxxxxx
Subject: RE: EM DG switchover across EM repositories?

Both targets would need to be in the same EM repository for EM to handle
this switchover.

-----Original Message-----
From: Herring, David [mailto:HerringD@xxxxxxx]
Sent: Monday, June 01, 2015 11:33 AM
To: oracle-l@xxxxxxxxxxxxx
Subject: EM DG switchover across EM repositories?

Folks,

Does anyone know if it's possible to perform a Data Guard switchover (from
within EM) from primary to physical standby where each is registered in a
different EM repository? We have DG configured so that the primary dbs are
in the UK and the physical standbys are in the US. The UK targets are
registered with a UK repository and the US targets are registered with a US
repository. Ideally we'd use EM for the switchover but I haven't been able
to confirm if this is possible or not using separate EM repositories.

Obviously actually performing the test will show me but I've been asked to
draw up all the steps and tests ahead of time, get everything ready and
meet various project plan deadlines with all this BEFORE doing anything,
which is why it's critical for me to know ahead of time if it's even
possible. I didn't see any references to doing this with separate EM
repositories in the doc and while I have an SR open with Oracle for
confirmation, I'm struggling in getting them to understand my question.

The configuration consistents of multiple 2 to 4-node RACs on each side
(UK and US), database ver is 11.2.0.4. The complexity for now is that the
US dbs are registered in a 12c repository whereas the UK dbs are registered
in a 11g repository. Once FW rules are pushed tomorrow night I should be
able to move those 11g-registered dbs to a 12c repository in the UK.

Thx.

Dave
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