Le JeanMimi wrote:
> First, thank you for your answers.
>
> For us, the point is availability (and not scalability).
>
> Say we have two databases A and B and two machines.
> We put A and B in RAC configuration :
> - instance A1 and B1 on machine 1
> - instance A2 and B2 on machine 2
> (A1 and A2 for database A, B1 and B2 for database B)
>
> If the machine 1 crashes, then all the work being done by A1 and B1
> failover to machine 2 (TAF) and everything is very fast ... and
> transparent.
>
> Does it make sense ?
> Thanks (i'm rather new to this)
>
>
> DA Morgan <damorgan_at_x.washington.edu> wrote in message news:<1099101941.420573_at_yasure>...
>
>>Le JeanMimi wrote:
>>
>>
>>>Hello,
>>>
>>>Is it possible to run more than one RAC instance on the same machine ?
>>>(to be exact : more than one RAC instance on the same IBM P690 machine
>>>partition - AIX 5.2) ?
>>>
>>>(we hope so ;)
>>>
>>>For instance :
>>>
>>>Machine Partition 1
>>>instance "A1" for the database "A"
>>>instance "B1" for the database "B"
>>>instance "C1" for the database "C"
>>>
>>>Machine Partition 2
>>>instance "A2" for the database "A"
>>>instance "B2" for the database "B"
>>>instance "C2" for the database "C"
>>>
>>>Same software version for all db.
>>>Btw is it necessary to have separate interconnect sets or can all the
>>>databases share the same interconnect ?
>>>
>>>Thanks in advance
>>>
>>>JM
>>
>>Possible yes. Reasonable is another question. The point of RAC is
>>high availability and scalability. Two instances on the same machine
>>gives you neither. In fact it decreases both. So what is it that you
>>are trying to accomplish?
>>
>>I believe you would need separate interconnects but I've never tried
>>it as it just seems totally counter-productive.
Makes no sense to me. Put one database on A, one on B and build two
schemas. Now you have half as many things to go wrong. What do you
think you accomplish with 2 System tablespaces, 2 UNDO tablespaces, 2
SGAs? I mean accomplish as in desirable?
--
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu
(replace 'x' with 'u' to respond)
Received on Sat Oct 30 2004 - 16:29:59 CDT
