Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Usenet -> c.d.o.server -> Re: What ramifications are there for running two Instances on one host server.

Re: What ramifications are there for running two Instances on one host server.

From: Fred Pierce <fpierce_at_avialantic.com>
Date: Fri, 26 Jan 2001 08:21:00 -0500
Message-ID: <3A7179BC.8772C1A5@avialantic.com>

Thanks for the reference. I have found lots of useful information on Jonathan's site. Thus far I haven't run into any serious problems since the instances I manage aren't terribly competitive, but I don't count on that always being true.

As Doug points out in his reply, there are lots of trade-offs. The fun part is identifying them all and figuring out the best course when you're driving from underneath the car, so to speak. Maybe someday I'll write a "real world" Oracle book. It would probably be a combination of Scott Adams and Dave Barry styles.

All in all, though, I don't know when I've had so much fun and gotten paid for it.

fdp



Fred Pierce (DNRC) www.avialantic.com/links/oracle.html www.Avialantic.com fpierce_at_avialantic.com MAAM World War II Weekend Airshow June 8-10 2001 www.maam.org/maamwwii.html
World Airshow News - www.wanews.com

"Howard J. Rogers" wrote:
>
> Hi Fred: regrettably, I can't recommend anything along those lines (though
> I'm sure someone else will be able to do so). I work in the idealised world
> of teaching people how Oracle works *in principle*, and in principle, you
> shouldn't do it!!
>
> I do sympathise, though. Oracle pricing is scary at best, and the
> temptation (and need) to skip on having multiple servers is correspondingly
> large. I suspect Jonathan Lewis might be your best source of advice on the
> potential pitfalls.
>
> Regards
> HJR
>
> "Fred Pierce" <fpierce_at_avialantic.com> wrote in message
> news:3A6ED437.3F6A1D4A_at_avialantic.com...
> > Howard, can you recommend any good papers etc. on multi-instance server
> > administration? Sometimes additional servers or consolidation aren't
> > options (I've been struggling for three years to bring together myriad
> > seperate projects each of which had their own instances for no good
> > reason that I could discern except politics and ignorance). With CPU
> > based pricing, I would expect management would be more inclined than
> > ever to cram everything they can on one server.
> >
> > In some cases, such as incompatible application requirements, I would
> > think it would be easier to tune seperate instances even if they are on
> > the same server. I/O contention I can figure out but am uncertain about
> > memory allocation, network traffic etc. Most of the tuning books in my
> > collection (admittedly I haven't had time to dig deeply) seem to assume
> > a monolithic operation where the DBA actually controls the configuration
> > instead of "making do" with an inherited environment. There must be
> > other "Balkanized" installations out there though, aren't there?
> >
> > fdp
> >
> > ---------------------------------------------------------
> > Fred Pierce (DNRC) Gee I hope nobody from work reads this...
> > www.Avialantic.com fpierce_at_avialantic.com
> > MAAM World War II Weekend Airshow June 8-10 2001
> > www.maam.org/maamwwii.html
> > World Airshow News - www.wanews.com
> > ---------------------------------------------------------
> >
> > "Howard J. Rogers" wrote:
> > >
> > > "toddthom" <orclnwsgrp_at_hotmail.com> wrote in message
> > > news:94io0r$nru$1_at_nnrp1.deja.com...
> > > > Hello Generous and All-Knowing,
> > > >
> > > > I'm a jdba and I'm currently involved in building an Operational Data
> > > > Store and a Data Warehouse on one HPUX (11.0) N-Class server......two
> > > > SID's one one node. We haven't actually built it yet, but, I thought
> > > > Oracle's rule was a one to one relationship with regard to instance
 and
> > > > database.....wouldn't this break the rule?
> > >
> > > It would only break it if you assume that a database is the same thing
 as a
> > > node. The node is the HP Server -one physical box. The database is the
> > > collection of controlfiles+datafiles+redo logs that relate to your Data
> > > Warehouse, and the second database is the collection of
> > > controlfiles+datafiles+redo logs that relate to your Operational
 Datastore.
> > > Two databases, one node. Nothing wrong in that.
> > >
> > > You will have to have two Instances managing those two
 databases -because
> > > the rule about 1 instance managing 1 database is always true (even in
> > > Parallel Server). Two Instances, one node. Nothing wrong with that,
> > > either.
> > >
> > > Except... that performance on either Instance will be affected by the
 work
> > > being done on the other, and the i/o on one database will be affected by
 the
> > > i/o on the other.
> > >
> > > So whilst there's nothing "wrong" with 2 or more databases and Instances
 on
> > > one node, it's not normally recommended for performance reasons.
> > >
> > > >If not, what configuration
> > > > recommendations would you make with regard to resources?
> > > >
> > >
> > > Extremely tricky to suggest anything without knowing the loads and work
> > > patterns for each database/instance. The simple (simplistic) advice is
 to
> > > go buy another HP Server.
> > >
> > > Regards
> > > HJR
> > >
> > > > Thanks
> > > >
> > > > Todd
> > > > Peace
> > > >
> > > >
> > > >
> > > > Sent via Deja.com
> > > > http://www.deja.com/
Received on Fri Jan 26 2001 - 07:21:00 CST

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US