can clustering use as load balacing

I want to have 3 MSSQL server that work at same time on shared
database(all opened a single data file on SAN for example). And request
for queries are send to those parallel and same sql servers to archive
more processing power and fail over feature?act as load balancing?
what can I do for load balancing heavy traffic queries like which can
done on web server?
thanks
SQL Server does not support shared-disk clustering for load balancing, though
there is a feature in SQL2005 called scalable shared database that allows you
to present the same database via a LUN to multiple SQL2005 instances for
read-only access.
Linchi
"Tarvirdi" wrote:

> I want to have 3 MSSQL server that work at same time on shared
> database(all opened a single data file on SAN for example). And request
> for queries are send to those parallel and same sql servers to archive
> more processing power and fail over feature?act as load balancing?
> what can I do for load balancing heavy traffic queries like which can
> done on web server?
> thanks
>
|||Linchi Shea wrote:
> SQL Server does not support shared-disk clustering for load balancing, though
> there is a feature in SQL2005 called scalable shared database that allows you
> to present the same database via a LUN to multiple SQL2005 instances for
> read-only access.
Dear Linchi,
Thanks for your response.
What you mean about sharing datafile?
For example I have A database named T1 with T1.mdf and want to have
another Database on other server(or same server to start test) and have
read only access to above T1.mdf? how implement it? which steps should I do?
I tried but failed because of "can create already exist file error"
Thanks
|||
> For example I have A database named T1 with T1.mdf and want to have
> another Database on other server(or same server to start test) and have
> read only access to above T1.mdf?
You can not do this
The limitation is NTFS, NTFS you can only have on server accessing the
volume at a time.
You can not do this on the same host either as SQL will have a problem
(cache comes to mind first)
the answer to your original question:
Q: can clustering be used as load balancing for SQL ?
A: no
|||
> there is a feature in SQL2005 called scalable shared database that allows
you
> to present the same database via a LUN to multiple SQL2005 instances for
> read-only access.
correct, but that is a "static" disk, presented RO to multiple hosts
you cannot have one host "writing" to and others "reading" from the same
disk