Re: 30 instances on one host

"Howard J. Rogers" wrote:

> I agree, actually (I have to... teaching Oracle classes mean I actually
> encounter at least 30 Instances on the one server every day). But as you
> say, that's a very special case, and hardly warrants what looks to be a
> burgeoning white paper as justification or explanation.
>
> One knows before walking into the training room that the student databases
> are going to be pathetically small, and quite useless for anything even
> approaching production standards. My whitepaper on the subject will be about
> three lines long, and that's because I'm occasionally verbose!!
>
> Regards
> HJR
>
> "Sean M" <smckeown_at_earthlink.net> wrote in message
> news:3D0ECDA9.F4675643_at_earthlink.net...
> > Daniel Morgan wrote:
> > >
> > > Sean M wrote:
> > >
> > > > It's not entirely academic - as I said in my other post, there are
> some
> > > > valid justifications for such a configuration (training, support,
> > > > etc.). But generally I agree - this sort of architecture is highly
> > > > specialized, and almost always used for situations where
> > > > performance/robustness/scalability are not the primary concern.
> > > >
> > > > Regards,
> > > > Sean
> > >
> > > I disagree. I can not believe there is any justification.
> > >
> > > I challenge anyone to give me a rationale whereby 10 instances makes
> more sense
> > > than 2 or 3.
> > >
> > > And lets make sure here that we are using the word 'instance' to mean
> 'instance'
> > > and not to mean 'datab ase'. You are talking about 10+ running Oracle
> > > executables. 10+ oracle_sids. 10+ * the number of threads in a single
> instance.
> >
> > Well, as I said in my other post, a training class for Oracle would be a
> > good example. Each student gets his or her own database (actual
> > distinct Oracle database) for exercises so as not to conflict with the
> > other students in the class (or in the next classroom over, for that
> > matter). Each student needs his/her own because the class is on
> > backup/recovery, or How to Build an Oracle Database, etc. (any sort of
> > DBA-type class where each student needs complete control over his or her
> > own database for the hands-on portion). Say 20 students per class, one
> > server per class, 20 instances/databases per server. That makes far
> > more sense than running 10 servers with 2 databases each for every class
> > in terms of cost and managability, which clearly have a higher priority
> > in this example than performance, etc. That's not to say performance
> > isn't a consideration - you don't want the students waiting around. But
> > you also don't want to spend the unjustifiable sums required to give
> > each student his own server. Hence, like everything else, a compromise
> > between cost/performance/managability must be struck.
> >
> > Another example might be a support organization. Each telephone analyst
> > might need a scratch instance to run simple tests on. You have 60
> > analysts. It would not make sense to buy 60 servers to run 60 test
> > instances on. You buy 2 or 3 big ones and run 20 or 30 many small
> > databases on each. Again, peformance takes a back seat to managability
> > and cost, but that's perfectly acceptable and sane - the correct choice
> > for this particular example.
> >
> > But again, these are special cases. In the vast majority of situations,
> > 20 or 30 databases on a single host would not be the correct, sane
> > choice.
> >
> > Regards,
> > Sean

Instances or databases? They are not the same thing.

Daniel Morgan Received on Thu Jun 20 2002 - 01:03:19 CDT