> We are running our application on a dual-processor machine. Now, it seems,
> by definition, a multi-processor machine is a Web Garden.

> imply that the WebGarden attribute of processModel in Machine.config,
needs
> to be set to "true"

> 1. This would mean that the aspnet worker process is utilizing only one

> 2. The %Processor Time counter would give a more optimistic read of the
> situation than is the case, because it will average out the time over 2
> processors when only one is being utilized?

> 1. This implies i have to use out-of-process technique for doing session
> state management, like the asp.net state service which i have heard is
about
> 15% slower.

> 15% slower.

> In summary, using a dual-processor machine is of benefit to asp.net onlyif
> WebGarden is set to "true" and an out-of-process technique for session
> management is being used?
>

"Vishal Gupta" <vishalg_99@hotmail.com> wrote in message
news:OuEDxsQDEHA.3152@TK2MSFTNGP10.phx.gbl...
> Hi,
>
> We are running our application on a dual-processor machine. Now, it seems,
> by definition, a multi-processor machine is a Web Garden. I guess this
would
> imply that the WebGarden attribute of processModel in Machine.config,
needs
> to be set to "true"? Here's my comements/questions pertaining to the two
> WebGarden scenarios:
>
> a. WebGarden="false"
> 1. This would mean that the aspnet worker process is utilizing only one
CPU?
> 2. The %Processor Time counter would give a more optimistic read of the
> situation than is the case, because it will average out the time over 2
> processors when only one is being utilized?
>
> b. WebGarden="true"
> 1. This implies i have to use out-of-process technique for doing session
> state management, like the asp.net state service which i have heard is
about
> 15% slower.
>
> In summary, using a dual-processor machine is of benefit to asp.net only
if
> WebGarden is set to "true" and an out-of-process technique for session
> management is being used?
>
> Any clarifications would be appreciated.
>
> Thanks.
>
>
>

"Alvin Bruney [MVP]" <vapor at steaming post office> wrote in message
news:uSPyyBXDEHA.2308@tk2msftngp13.phx.gbl...
> > We are running our application on a dual-processor machine. Now, it
seems,
> > by definition, a multi-processor machine is a Web Garden.
>
> No. This definition is the cause of your confusion. A web garden is a
> process model responsible for 'distributing the work to several
> processes, one per CPU, each with processor affinity set to its CPU'. This
> means in a nutshell that each Aspnet worker process will run on its
> dedicated cpu something called cpu affinity. The documentation for
framework
> 1.0 is wrong in this regard so don't read it.
>
> In IIS6, the model changes fundamental which only adds to the confusion,
but
> the underlying fact remains: In a web garden, the IIS worker process will
> run on one particular cpu. This is really all there is to it. You may take
> from this answer that there can be as many worker processes as there are
cpu
> units available, but no more since a worker process sharing a cpu opens
the
> door to cpu contention and deadlock. When web gardening is turned off,
there
> is only one worker process irrespective of the number of cpu units
> available. This is the default behavior. There is more confusion here with
> IIS6 because IIS6 can have many aspnet worker processes, one for each
> application pool, even when web gardening is disabled. In fact, this is
the
> default behavior. How? the short answer is that the aspnet worker process
is
> simply a copy of the iis worker process.
>
> I guess this would
> > imply that the WebGarden attribute of processModel in Machine.config,
> needs
> > to be set to "true"
>
> You have the shoe on backward. Since a multi cpu system by default will
use
> the pool of cpu's as it sees fit, to force one process to always execute
on
> one cpu (a web garden with processor affinity), you have to specifically
> turn it on. Web gardening is off by default. Think of it this way, multi
> processor systems existed long before webgardening so web gardening is not
> the default behavior. Applications knew how to take advantage of multi
> processor systems long ago.
>
> > 1. This would mean that the aspnet worker process is utilizing only one
> CPU?
> The normal behavior of an OS is for it to utilize the cpu resource pool
how
> it sees fit by scheduling jobs on cpu's which have less work load to not
> overwork one cpu while leading to cpu starvation in others. For this very
> reason, the default behavior of a disabled webgarden is correct. The OS
> should be allowed to scheduled jobs based on resources. A web garden
removes
> this qualification. An application running in default process mode, ie
with
> web gardening turned off, utilizes every cpu in the pool optimistically.
>
> > 2. The %Processor Time counter would give a more optimistic read of the
> > situation than is the case, because it will average out the time over 2
> > processors when only one is being utilized?
> No because of 1.
>
> > 1. This implies i have to use out-of-process technique for doing session
> > state management, like the asp.net state service which i have heard is
> about
> > 15% slower.
>
> It only implies this because the processes are running independently on
> their own dedicated cpu. There can be no cpu sharing, likewise, data
sharing
> is restricted since these applications are running in their own little
> worlds. Consider it like the processes are running inside their own
> containers isolated from each other. If you need to share information
among
> the cpu, the processes must be able to talk to a common external thing(for
> lack of a better word). Which is why you need a stateserver.
>
> like the asp.net state service which i have heard is about
> > 15% slower.
> ohhhhhhhhh, more like 10 to 25 percent, closer to 10 (Dino Esposito). My
> independent measurements were undiscernable under light loads (< 10
users).
>
> > In summary, using a dual-processor machine is of benefit to asp.net
onlyif
> > WebGarden is set to "true" and an out-of-process technique for session
> > management is being used?
> >
>
> I'd leave that up to you to correct this now that you understand what is
> going on.
>
> I've not come across a situation to use web gardening yet. But then again,
i
> havent been doing this for a very long time. A mutli-processor system
> running without affinity has always been able to handle the load thrown at
> it where I come from. Feel free to yell at me if you don't agree with
> anything in there.
>
> --
> Regards,
> Alvin Bruney [ASP.NET MVP]
> Got tidbits? Get it here...
> http://tinyurl.com/3he3b
> "Vishal Gupta" <vishalg_99@hotmail.com> wrote in message
> news:OuEDxsQDEHA.3152@TK2MSFTNGP10.phx.gbl...
> > Hi,
> >
> > We are running our application on a dual-processor machine. Now, it
seems,
> > by definition, a multi-processor machine is a Web Garden. I guess this
> would
> > imply that the WebGarden attribute of processModel in Machine.config,
> needs
> > to be set to "true"? Here's my comements/questions pertaining to the two
> > WebGarden scenarios:
> >
> > a. WebGarden="false"
> > 1. This would mean that the aspnet worker process is utilizing only one
> CPU?
> > 2. The %Processor Time counter would give a more optimistic read of the
> > situation than is the case, because it will average out the time over 2
> > processors when only one is being utilized?
> >
> > b. WebGarden="true"
> > 1. This implies i have to use out-of-process technique for doing session
> > state management, like the asp.net state service which i have heard is
> about
> > 15% slower.
> >
> > In summary, using a dual-processor machine is of benefit to asp.net only
> if
> > WebGarden is set to "true" and an out-of-process technique for session
> > management is being used?
> >
> > Any clarifications would be appreciated.
> >
> > Thanks.
> >
> >
> >
>
>
>