Limiting parallelism to only some of the processors?

We are considering turning off parallelism on our server. I've read a
few articles that also talk about limiting parallelism to a certain
number of processors instead of turning it off completely. They say
that this requirement is rare but don't describe situations where it
might be useful.
Does anyone have any information about scenarios where limiting
parallelism to a certain number of processors could be useful?
ThanksIt is very often more efficient to set sql server to use only one cpu for
each worker thread. Testing will be what determines whether it is effective
on your data with your code.
TheSQLGuru
President
Indicium Resources, Inc.
<pshroads@.gmail.com> wrote in message
news:1177369370.045211.148410@.l77g2000hsb.googlegroups.com...
> We are considering turning off parallelism on our server. I've read a
> few articles that also talk about limiting parallelism to a certain
> number of processors instead of turning it off completely. They say
> that this requirement is rare but don't describe situations where it
> might be useful.
> Does anyone have any information about scenarios where limiting
> parallelism to a certain number of processors could be useful?
> Thanks
>|||On 24.04.2007 01:02, pshroads@.gmail.com wrote:
> We are considering turning off parallelism on our server. I've read a
> few articles that also talk about limiting parallelism to a certain
> number of processors instead of turning it off completely. They say
> that this requirement is rare but don't describe situations where it
> might be useful.
> Does anyone have any information about scenarios where limiting
> parallelism to a certain number of processors could be useful?
Did you see these?
http://blogs.msdn.com/sqltips/archi.../14/466387.aspx
http://blogs.msdn.com/sqlcat/archiv.../30/498415.aspx
robert|||Hi,
Are you using Hyperthreaded CPU's? If you are look at these threads in this
NG.
Dated April 12th - Option (MAXDOP 1)
Dated April 19th - Hyperthreaded CPU's
Chris
<pshroads@.gmail.com> wrote in message
news:1177369370.045211.148410@.l77g2000hsb.googlegroups.com...
> We are considering turning off parallelism on our server. I've read a
> few articles that also talk about limiting parallelism to a certain
> number of processors instead of turning it off completely. They say
> that this requirement is rare but don't describe situations where it
> might be useful.
> Does anyone have any information about scenarios where limiting
> parallelism to a certain number of processors could be useful?
> Thanks
>

Limiting parallelism to only some of the processors?

We are considering turning off parallelism on our server. I've read a
few articles that also talk about limiting parallelism to a certain
number of processors instead of turning it off completely. They say
that this requirement is rare but don't describe situations where it
might be useful.
Does anyone have any information about scenarios where limiting
parallelism to a certain number of processors could be useful?
ThanksIt is very often more efficient to set sql server to use only one cpu for
each worker thread. Testing will be what determines whether it is effective
on your data with your code.
--
TheSQLGuru
President
Indicium Resources, Inc.
<pshroads@.gmail.com> wrote in message
news:1177369370.045211.148410@.l77g2000hsb.googlegroups.com...
> We are considering turning off parallelism on our server. I've read a
> few articles that also talk about limiting parallelism to a certain
> number of processors instead of turning it off completely. They say
> that this requirement is rare but don't describe situations where it
> might be useful.
> Does anyone have any information about scenarios where limiting
> parallelism to a certain number of processors could be useful?
> Thanks
>|||On 24.04.2007 01:02, pshroads@.gmail.com wrote:
> We are considering turning off parallelism on our server. I've read a
> few articles that also talk about limiting parallelism to a certain
> number of processors instead of turning it off completely. They say
> that this requirement is rare but don't describe situations where it
> might be useful.
> Does anyone have any information about scenarios where limiting
> parallelism to a certain number of processors could be useful?
Did you see these?
http://blogs.msdn.com/sqltips/archive/2005/09/14/466387.aspx
http://blogs.msdn.com/sqlcat/archive/2005/11/30/498415.aspx
robert|||Hi,
Are you using Hyperthreaded CPU's? If you are look at these threads in this
NG.
Dated April 12th - Option (MAXDOP 1)
Dated April 19th - Hyperthreaded CPU's
Chris
<pshroads@.gmail.com> wrote in message
news:1177369370.045211.148410@.l77g2000hsb.googlegroups.com...
> We are considering turning off parallelism on our server. I've read a
> few articles that also talk about limiting parallelism to a certain
> number of processors instead of turning it off completely. They say
> that this requirement is rare but don't describe situations where it
> might be useful.
> Does anyone have any information about scenarios where limiting
> parallelism to a certain number of processors could be useful?
> Thanks
>

Limit the total number of reports submitted

I have a machine with 4 physical processors and 16 logical processors. SSRS
allows up to 32 reports to be submitted for processing through subscriptions.
This fails miserably because the machine does not have the memory or
capacity to process this many at a time. Is there a config parameter that
tells SSRS to never submit more than 4 at a time including retries?On Dec 16, 3:18 pm, Earl Newcomer
<EarlNewco...@.discussions.microsoft.com> wrote:
> I have a machine with 4 physical processors and 16 logical processors. SSRS
> allows up to 32 reports to be submitted for processing through subscriptions.
> This fails miserably because the machine does not have the memory or
> capacity to process this many at a time. Is there a config parameter that
> tells SSRS to never submit more than 4 at a time including retries?
This could be a long shot, but you might try limiting the
MaxActiveReqForOneUser parameter normally found in: C:\Program Files
\Microsoft SQL Server\MSSQL.2\Reporting Services\ReportManager
\RSWebApplication.config. If this does not help, you might try
building a custom .NET delivery application/system to limit the number
of reports. Hope this helps.
Regards,
Enrique Martinez
Sr. Software Consultant|||Ed,
You were right on track. The parameter for subscriptions is in the file:
Program Files\Microsoft SQL Server\MSSQL\Reporting
Services\ReportServer\RSReportServer.config.
The parameter is under the <service> tag and is:
<MaxQueueThreads>0</MaxQueueThreads>
The default of 0 seems to allow SSRS to submit up to 2 reports per
recognized logical processor. I set this value to 3 and no more than 3
reports were submitted at a time even though we have 16 logical processors
and 4 physical processors.
Thanks for jogging my memory and sending me on the hunt.
"EMartinez" wrote:
> On Dec 16, 3:18 pm, Earl Newcomer
> <EarlNewco...@.discussions.microsoft.com> wrote:
> > I have a machine with 4 physical processors and 16 logical processors. SSRS
> > allows up to 32 reports to be submitted for processing through subscriptions.
> > This fails miserably because the machine does not have the memory or
> > capacity to process this many at a time. Is there a config parameter that
> > tells SSRS to never submit more than 4 at a time including retries?
>
> This could be a long shot, but you might try limiting the
> MaxActiveReqForOneUser parameter normally found in: C:\Program Files
> \Microsoft SQL Server\MSSQL.2\Reporting Services\ReportManager
> \RSWebApplication.config. If this does not help, you might try
> building a custom .NET delivery application/system to limit the number
> of reports. Hope this helps.
> Regards,
> Enrique Martinez
> Sr. Software Consultant
>|||On Dec 19, 4:46 pm, Earl Newcomer
<EarlNewco...@.discussions.microsoft.com> wrote:
> Ed,
> You were right on track. The parameter for subscriptions is in the file:
> Program Files\Microsoft SQL Server\MSSQL\Reporting
> Services\ReportServer\RSReportServer.config.
> The parameter is under the <service> tag and is:
> <MaxQueueThreads>0</MaxQueueThreads>
> The default of 0 seems to allow SSRS to submit up to 2 reports per
> recognized logical processor. I set this value to 3 and no more than 3
> reports were submitted at a time even though we have 16 logical processors
> and 4 physical processors.
> Thanks for jogging my memory and sending me on the hunt.
> "EMartinez" wrote:
> > On Dec 16, 3:18 pm, Earl Newcomer
> > <EarlNewco...@.discussions.microsoft.com> wrote:
> > > I have a machine with 4 physical processors and 16 logical processors. SSRS
> > > allows up to 32 reports to be submitted for processing through subscriptions.
> > > This fails miserably because the machine does not have the memory or
> > > capacity to process this many at a time. Is there a config parameter that
> > > tells SSRS to never submit more than 4 at a time including retries?
> > This could be a long shot, but you might try limiting the
> > MaxActiveReqForOneUser parameter normally found in: C:\Program Files
> > \Microsoft SQL Server\MSSQL.2\Reporting Services\ReportManager
> > \RSWebApplication.config. If this does not help, you might try
> > building a custom .NET delivery application/system to limit the number
> > of reports. Hope this helps.
> > Regards,
> > Enrique Martinez
> > Sr. Software Consultant
Glad you found your solution. Let me know if I can be of further
assistance.
Regards,
Enrique Martinez
Sr. Software Consultant