RE: multiple databases in a single RAC cluster
- From: "Bobak, Mark" <Mark.Bobak@xxxxxxxxxxxx>
- To: "orcl@xxxxxxxxxxx" <orcl@xxxxxxxxxxx>
- Date: Wed, 12 Nov 2008 01:20:00 -0500
Hi Bob,
I run a RAC configuration with multiple databases.
I have a 3 node cluster of HP DL-585s, each running 4 dual core Opterons, and
64GB RAM.
Interconnect is dual bonded Gig-E NICs.
On each node, I'm running 4 database instances, plus an ASM instance.
Specifically, RedHat Linux, RHEL4U6.
CRS is 11g, ASM is 11g, and I have 1 database at 11g (11.1.0.6) and 3 databases
at 10gR2 (10.2.0.3).
The RAC has been in place for about 2 years, initially w/ the three 10gR2
databases and no 11g components.
About a year ago, I upgraded CRS and ASM to 11g, and added the 11g database.
It's all quite stable and running well. It really comes down to just a few
factors:
1.) Do you have the CPU capacity?
2.) Do you have the memory?
3.) Do you have the interconnect bandwidth?
So, here's the downside:
When the call comes in, and someone says "Hey, the system is slow!" or "My
query is hanging!", you've got a lot more work to do. Is the problem systemic?
Is it related to just one node, or across the cluster? In my case, there's 12
different database instances to look at. It can be a lot more work, just
tracking down the root cause of a performance problem.
But, bottom line, it's not horrendously more complex running a RAC cluster w/
multiple databases than it is to run one database on RAC. Once you have the
RAC knowledge and expertise, it's just more of the same. The key is making
sure you have enough memory/CPU/interconnect capacity.
Hope that helps,
-Mark
________________________________________
From: oracle-l-bounce@xxxxxxxxxxxxx [oracle-l-bounce@xxxxxxxxxxxxx] On Behalf
Of Bob [orcl@xxxxxxxxxxx]
Sent: Tuesday, November 11, 2008 11:39 PM
Cc: oracle-l
Subject: Re: multiple databases in a single RAC cluster
Thanks Matt, wondering if there are any specific white papers ( I
couldn't find any)
Im thinking this would be a very complex configuration ie
asm disk separation - per database -
data guard DR for multiple databases....
the interconnect would really take a beating...probably needing nics
for each database...
I mean that sounds like a "very" complex.
The client here is looking to save allot of money by consolidating
environments of 15 databases on single servers with active passive
veritas clusters - moving them to rac
The strategy is to save money (hardware and support) - I'm just not
feeling it...
Im looking for some white papers for this type of configuration, and
feedback for costs.
To me rac is excellent for a single database with the need for extremely
high level of connections (amazon type, banking, financial), and high
availability, but mixing many disparate (1-4 single application)
databses into a cluster to save money just dosnt make sense.
Bob
Matthew Zito wrote:
> Yes, absolutely, we have one customer who has an 8 node RAC cluster that's
> running 12 databases, each with between 2 and 8 instances, and a pile of
> other customers with 2-4 node clusters with multiple databases. I'm sure
> there's some internal limitations as to the number of services that can be
> registered in the CRS, but I doubt many people run into it.
>
>
> Thanks,
> Matt
>
> --
> Matthew Zito
> Chief Scientist
> GridApp Systems
> P: 646-452-4090
> mzito@xxxxxxxxxxx
> http://www.gridapp.com
>
>
>
> -----Original Message-----
> From: oracle-l-bounce@xxxxxxxxxxxxx on behalf of Bob
> Sent: Tue 11/11/2008 9:12 PM
> To: oracle-l
> Subject: multiple databases in a single RAC cluster
>
> Hi, As much as Ive been browsing / studying rac... Im looking for a
> definitive answers about how many "databases" can be on one rac cluster.
>
> Say I want to have 4 independent databases on one cluster, is that
> possible? I understand one can easily have multiple instances pointing
> to a single database (sga, control_file, db_name, spfile, archive_dest,
> etc) but what about several independent databses?
>
> Any documents referencing this?
>
> I found this on ask tom... just wanted to confirm with this group,
> probably in a more concise manner.
> http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:529123700346381713
>
> So, How many databases (sga, control_file, db_name, spfile,
> archive_dest, etc) can be in a single rac cluster?
>
> thanks
>
> Bob
> --
> //www.freelists.org/webpage/oracle-l
>
>
>
>
--
//www.freelists.org/webpage/oracle-l
--
//www.freelists.org/webpage/oracle-l
Other related posts:
