----- Original Message -----
Sent: Thursday, August 07, 2003 7:39
PM
Subject: RE: 100 instances on same server
!!!
100 instances is way too much even
(especially?) if Win2K is the OS in question.
Each instance means another service, and
each service means spawning and maintaining
multithreaded process... On Windows half
of available RAM is taken by default for kernel
processes and the other half is all that
all other apps can hope to get. In your case with
4 GB of RAM on the system each of 100
instances will be getting 20 generous MB. Not
enough by any means, not even considering way too many
threads that will befell (say
max 4?) CPUs.
Having said that, le'mee admit a sin: we
run with success (meaning nobody complains
about performance) 28 concurrent
development instances on powerful (at least it used
to be 4 years ago) 4x450 PIII Xeon CPUs
with full 1GB of RAM and 21 x 18 GB HDD in
few RAID 5 containers (sorry for violating
BAARF principles). Although we do run overly
large number of instances on a single
Windows NT 4 box, in reality most of them are
used sparsely, and that's why getting away
with it seems to work.
Now back to your case - I'd warmly advise
to reconsider one box running 100 instances
assumption. Whatever you put there - will
likely melt.
On the other hand if your all 100 of your
workstations are same, or form few groups
of same hardware, investing in
512 MB of RAM for each of 100
workstations (should
be much cheaper comparatively)
and in 100 licenses (at approx $30 each)
for Norton
Ghost Enterprise then:
- Slash the PC OS and do fresh
install (with SP's and unavoidable patches)
then install Oracle and create one local
database with application installed
and configured,
- Take Ghost image of a
system,
- "Push" the image across all
workstations (on condition it hardware is exactly
alike) using Norton Multicast Server
is a "piece of cake", and literally one "click"
job.
- See that the same image is
used over and over again whenever the next
round of training is about to take place.
Fiddling with Ghost is NOT a DBA job, but
any sysadmin type should pull it
with ease (and gratitude, if I may say so
;-).
Branimir
Thanks for the replies so far. Considering the fact that my database is
tiny ( just around 3 GB ), How many of them can work on same server? I can
just test with 5 instances, with limited hardware. Will the CPUs be able to
take load of 100 instances? Is it worth experimenting this?
I am on 8.1.7.4 and the application is already built. I stand no chance
of changing the code. That is why using individual schemas for individual
users is not an option. Right now I am just asked if 100 instances can run
on same server and I don't have solid answer.
Just on side note, can I ask, What is the maximum number of
instances anyone has ever worked/heard being installed with in same
server?
Thanks again.
Dilip.
----- Original Message -----
Sent: Thursday, August 07, 2003 11:54
AM
Subject: Re: What books recommended
for Data Modeling ?
100 instances wohhhhh . If you are in 9i look at
possibilities like context
or label security . or creating another
schema .
-ak
----- Original Message -----
To:
"Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent:
Wednesday, August 06, 2003 9:24 PM
> I have not heard
installing hundred database instances on same server.
> Maybe you
should think creating one instance, and then hundred schemas in
>
it.
>
> Guang
>
> On Wed, 6 Aug 2003, Dilip Patel
wrote:
>
> > Hi All,
> > Need some
suggestions/Input.
> >
> > My application database is
8.1.7, NOARCHIVELOG, WIN200,
> > total size 4 GB, more of single
user OLTP client-server application.
> >
> > Now the
customer wants to give training on this application to
hundred
trainees
> > at a time. For this he wants to install
hundred database instances on
same
> > server machine,
which *each* will be accessed simultaneously from 100
different
>
> client workstations.
> >
> > The reasons for
installing all instances on same machine are
> > - to avoid
re-installing databases on 100 workstations after each round
of
>
> training.
> > - No user should see any other user's
data.
> >
> > Please suggest if this approach is
feasible or is it at all possible.
Tested this with upto 5 instances,
and
> > it seems to work. The customer is willing to upgrade to
any hardware
needed for
> > this setup.
> >
>
> Thanks in advance for your time.
> >
> >
Dilip.
> >
>
> --
> Please see the official
ORACLE-L FAQ: http://www.orafaq.net
> --
>
Author: Guang Mei
> INET: [EMAIL PROTECTED]
>
> Fat City
Network Services -- 858-538-5051 http://www.fatcity.com
> San
Diego, California -- Mailing
list and web hosting services
>
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