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Confused about ASP, "sessions", and queuing of multiple requests

P: n/a
Hi,

I'm trying to understand a situation where ASP seems to be "blocking" of
"queuing" requests. This is on a Win2K Advanced Server, with IIS5.

I've seen some posts (e.g.,
http://groups.google.com/groups?hl=e...ngxa06.phx.gbl)
that indicate that ASP will queue up requests when they come in with the
same "session".

My first question is "Can someone confirm that this is true?" (see below).

My second is regarding what "same session" means in this context?

Several of the posts that I've seen with respect to this queuing just say
"session", but I've also seen some posts that say "ASP session", and which
specifically mention "the ASP Session object". This latter reference ("ASP
Session object") is more precise, but my testing (again, see below) seems to
indicate that this interpretation of "session" is not "ASP Session object".

Here's the test that tried:

1) I installed the Waitfor from ServerObjects
(http://www.serverobjects.com/products.htm), and created a small "text.txt"
file in c:\.

2) I put Waitfor.asp in my website.

3) I ran Performance Monitor and added the "Requests Queued" counter

4) Using IE, I went to http://myserver/waitfor.asp

5) Once it connected, I started clicking the IE Refresh button
As I clicked the IE Refresh button, I could see the "Requests Queued"
counter climb in Performance Monitor.

The above test SEEM to at least indicate that ASP will *INDEED* only process
a single request from IE, i.e., that ASP *IS* queuing, but I'm still
confused about under what circumstances this queuing will happen (what does
"session" mean in this context?).

Can someone clarify this?

Thanks, and apologies for both the cross-post and somewhat long post...
Jul 19 '05 #1
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11 Replies


P: n/a
That's true since IIS 3.0 and there are occasions when you don't need to
make quick refresh to see it in action.

For example, this is necessary when the IE is making simultaneous requests
to the IIS. Exemple of this are when you are dividing your page using
Frameset: each frame contains one HTML page as its source. Refreshing a
frameset then require to ask the server for more than one HTML page.

Another example is when the source of an objet is an ASP page, like this:

<img src="get_the_image.asp">

The use of Javascript and of other advanced facilities for requesting data
from one or more ASP pages also rise the possibilities of having multiple
simultaneous requests to the web server. It is clear from those example
that the server cannot run these requests in parallele because of the
possibility that the codes inside theses pages can make contradictory
changes to Session variables, global variables and/or other objects, like
backend requests to a SQL-Server. This should clear any confusion into your
mind.

By the way, using things like WaitFor and others objets for timing in ASP
can result in a severe degradation of performance from the IIS and their
usages must be reserved to the cases when they are strictly necessary.

S. L.

"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:u0***************@TK2MSFTNGP11.phx.gbl...
Hi,

I'm trying to understand a situation where ASP seems to be "blocking" of
"queuing" requests. This is on a Win2K Advanced Server, with IIS5.

I've seen some posts (e.g.,
http://groups.google.com/groups?hl=e...ngxa06.phx.gbl) that indicate that ASP will queue up requests when they come in with the
same "session".

My first question is "Can someone confirm that this is true?" (see below).

My second is regarding what "same session" means in this context?

Several of the posts that I've seen with respect to this queuing just say
"session", but I've also seen some posts that say "ASP session", and which
specifically mention "the ASP Session object". This latter reference ("ASP Session object") is more precise, but my testing (again, see below) seems to indicate that this interpretation of "session" is not "ASP Session object".
Here's the test that tried:

1) I installed the Waitfor from ServerObjects
(http://www.serverobjects.com/products.htm), and created a small "text.txt" file in c:\.

2) I put Waitfor.asp in my website.

3) I ran Performance Monitor and added the "Requests Queued" counter

4) Using IE, I went to http://myserver/waitfor.asp

5) Once it connected, I started clicking the IE Refresh button
As I clicked the IE Refresh button, I could see the "Requests Queued"
counter climb in Performance Monitor.

The above test SEEM to at least indicate that ASP will *INDEED* only process a single request from IE, i.e., that ASP *IS* queuing, but I'm still
confused about under what circumstances this queuing will happen (what does "session" mean in this context?).

Can someone clarify this?

Thanks, and apologies for both the cross-post and somewhat long post...

Jul 19 '05 #2

P: n/a
Sylvain,

Thanks for responding...

Re. Waitfor, I just installed it for the test I described.

Sorry if I'm being obtuse. I think I understand that one IE instance can
generate multiple HTTP requests into IIS, e.g., in the instances that you
described. In our case, I think your example of setting an IMG SRC to an
ASP is exactly what we have, with multiple of these IMGs on one page.

But, I guess I'm still unclear about when IIS/ASP will or will not handle
these multiple requests in a "queuing" fashion vs. not in a queuing fashion.

What exactly determines this? As I mentioned, the posts I've seen vaguely
mention "in the same session", without clearly defining what they mean by a
"session".

Actually, the reason that I'm chasing all of this around is that we are
running IIS on a multiprocessor server. With the IE client firing multiple
requests to IIS, we thought that the multiple requests from IE would be
spread across the multiple processors.

But on our production server, instead, for a given user operation at the
IE/client end, which, again, creates several HTTP requests to IIS, we're
seeing CPU activity on 1 CPU, then the next CPU, then the next CPU, etc.,
until the user operation is complete.

The conclusion we're coming to is that for some reason ASP on the production
server is not handling the multiple requests "in parallel", but rather
queuing the requests (we see the parallel processing on a different
multiprocessor server that we use for testing, but not on the production
machine).

We just cannot figure out what is different between these 2 machines that
would cause queuing the requests in one case, but not in the other.

Thanks,
Jim

"Sylvain Lafontaine" <sylvain aei ca (fill the blanks, no spam please)>
wrote in message news:O7***************@tk2msftngp13.phx.gbl...
That's true since IIS 3.0 and there are occasions when you don't need to
make quick refresh to see it in action.

For example, this is necessary when the IE is making simultaneous requests
to the IIS. Exemple of this are when you are dividing your page using
Frameset: each frame contains one HTML page as its source. Refreshing a
frameset then require to ask the server for more than one HTML page.

Another example is when the source of an objet is an ASP page, like this:

<img src="get_the_image.asp">

The use of Javascript and of other advanced facilities for requesting data
from one or more ASP pages also rise the possibilities of having multiple
simultaneous requests to the web server. It is clear from those example
that the server cannot run these requests in parallele because of the
possibility that the codes inside theses pages can make contradictory
changes to Session variables, global variables and/or other objects, like
backend requests to a SQL-Server. This should clear any confusion into your mind.

By the way, using things like WaitFor and others objets for timing in ASP
can result in a severe degradation of performance from the IIS and their
usages must be reserved to the cases when they are strictly necessary.

S. L.

"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:u0***************@TK2MSFTNGP11.phx.gbl...
Hi,

I'm trying to understand a situation where ASP seems to be "blocking" of
"queuing" requests. This is on a Win2K Advanced Server, with IIS5.

I've seen some posts (e.g.,

http://groups.google.com/groups?hl=e...ngxa06.phx.gbl)
that indicate that ASP will queue up requests when they come in with the
same "session".

My first question is "Can someone confirm that this is true?" (see below).
My second is regarding what "same session" means in this context?

Several of the posts that I've seen with respect to this queuing just say "session", but I've also seen some posts that say "ASP session", and which specifically mention "the ASP Session object". This latter reference

("ASP
Session object") is more precise, but my testing (again, see below)

seems to
indicate that this interpretation of "session" is not "ASP Session

object".

Here's the test that tried:

1) I installed the Waitfor from ServerObjects
(http://www.serverobjects.com/products.htm), and created a small

"text.txt"
file in c:\.

2) I put Waitfor.asp in my website.

3) I ran Performance Monitor and added the "Requests Queued" counter

4) Using IE, I went to http://myserver/waitfor.asp

5) Once it connected, I started clicking the IE Refresh button
As I clicked the IE Refresh button, I could see the "Requests Queued"
counter climb in Performance Monitor.

The above test SEEM to at least indicate that ASP will *INDEED* only

process
a single request from IE, i.e., that ASP *IS* queuing, but I'm still
confused about under what circumstances this queuing will happen (what

does
"session" mean in this context?).

Can someone clarify this?

Thanks, and apologies for both the cross-post and somewhat long post...


Jul 19 '05 #3

P: n/a
Sylvain,

BTW, I forgot to mention:

If I run my Waitfor test with 2 different instances of IE (on same machine,
but 2nd IE started from Start, not using Ctrl-N) simultaneously, I see
Requests Executing in Perfmon as 2, i.e., in this situation, IIS *IS*
apparently processing both requests simultaneously/in parallel.

Like I said, I'm confused about what is different (specifically) between the
above test, and generating multiple HTTP requests from a single IE
instance...

"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:Oi****************@TK2MSFTNGP11.phx.gbl...
Sylvain,

Thanks for responding...

Re. Waitfor, I just installed it for the test I described.

Sorry if I'm being obtuse. I think I understand that one IE instance can
generate multiple HTTP requests into IIS, e.g., in the instances that you
described. In our case, I think your example of setting an IMG SRC to an
ASP is exactly what we have, with multiple of these IMGs on one page.

But, I guess I'm still unclear about when IIS/ASP will or will not handle
these multiple requests in a "queuing" fashion vs. not in a queuing fashion.
What exactly determines this? As I mentioned, the posts I've seen vaguely
mention "in the same session", without clearly defining what they mean by a "session".

Actually, the reason that I'm chasing all of this around is that we are
running IIS on a multiprocessor server. With the IE client firing multiple requests to IIS, we thought that the multiple requests from IE would be
spread across the multiple processors.

But on our production server, instead, for a given user operation at the
IE/client end, which, again, creates several HTTP requests to IIS, we're
seeing CPU activity on 1 CPU, then the next CPU, then the next CPU, etc.,
until the user operation is complete.

The conclusion we're coming to is that for some reason ASP on the production server is not handling the multiple requests "in parallel", but rather
queuing the requests (we see the parallel processing on a different
multiprocessor server that we use for testing, but not on the production
machine).

We just cannot figure out what is different between these 2 machines that
would cause queuing the requests in one case, but not in the other.

Thanks,
Jim

"Sylvain Lafontaine" <sylvain aei ca (fill the blanks, no spam please)>
wrote in message news:O7***************@tk2msftngp13.phx.gbl...
That's true since IIS 3.0 and there are occasions when you don't need to
make quick refresh to see it in action.

For example, this is necessary when the IE is making simultaneous requests
to the IIS. Exemple of this are when you are dividing your page using
Frameset: each frame contains one HTML page as its source. Refreshing a
frameset then require to ask the server for more than one HTML page.

Another example is when the source of an objet is an ASP page, like this:
<img src="get_the_image.asp">

The use of Javascript and of other advanced facilities for requesting data from one or more ASP pages also rise the possibilities of having multiple simultaneous requests to the web server. It is clear from those example
that the server cannot run these requests in parallele because of the
possibility that the codes inside theses pages can make contradictory
changes to Session variables, global variables and/or other objects, like backend requests to a SQL-Server. This should clear any confusion into

your
mind.

By the way, using things like WaitFor and others objets for timing in ASP can result in a severe degradation of performance from the IIS and their
usages must be reserved to the cases when they are strictly necessary.

S. L.

"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:u0***************@TK2MSFTNGP11.phx.gbl...
Hi,

I'm trying to understand a situation where ASP seems to be "blocking" of "queuing" requests. This is on a Win2K Advanced Server, with IIS5.

I've seen some posts (e.g.,

http://groups.google.com/groups?hl=e...ngxa06.phx.gbl)
that indicate that ASP will queue up requests when they come in with the same "session".

My first question is "Can someone confirm that this is true?" (see below).
My second is regarding what "same session" means in this context?

Several of the posts that I've seen with respect to this queuing just say "session", but I've also seen some posts that say "ASP session", and which specifically mention "the ASP Session object". This latter reference

("ASP
Session object") is more precise, but my testing (again, see below)

seems
to
indicate that this interpretation of "session" is not "ASP Session

object".

Here's the test that tried:

1) I installed the Waitfor from ServerObjects
(http://www.serverobjects.com/products.htm), and created a small

"text.txt"
file in c:\.

2) I put Waitfor.asp in my website.

3) I ran Performance Monitor and added the "Requests Queued" counter

4) Using IE, I went to http://myserver/waitfor.asp

5) Once it connected, I started clicking the IE Refresh button
As I clicked the IE Refresh button, I could see the "Requests Queued"
counter climb in Performance Monitor.

The above test SEEM to at least indicate that ASP will *INDEED* only

process
a single request from IE, i.e., that ASP *IS* queuing, but I'm still
confused about under what circumstances this queuing will happen (what

does
"session" mean in this context?).

Can someone clarify this?

Thanks, and apologies for both the cross-post and somewhat long post...



Jul 19 '05 #4

P: n/a
If you start a new instance of IE, then it does not share any in-memory
cookies (include ASP session state cookie) with the first IE instance. As
far as IIS is concerned, this is two separate ASP sessions. That is why you
are probably seeing parallel processing.

Cheers
Ken

"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:ez****************@tk2msftngp13.phx.gbl...
: Sylvain,
:
: BTW, I forgot to mention:
:
: If I run my Waitfor test with 2 different instances of IE (on same
machine,
: but 2nd IE started from Start, not using Ctrl-N) simultaneously, I see
: Requests Executing in Perfmon as 2, i.e., in this situation, IIS *IS*
: apparently processing both requests simultaneously/in parallel.
:
: Like I said, I'm confused about what is different (specifically) between
the
: above test, and generating multiple HTTP requests from a single IE
: instance...
:
:
:
: "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
: news:Oi****************@TK2MSFTNGP11.phx.gbl...
: > Sylvain,
: >
: > Thanks for responding...
: >
: > Re. Waitfor, I just installed it for the test I described.
: >
: > Sorry if I'm being obtuse. I think I understand that one IE instance
can
: > generate multiple HTTP requests into IIS, e.g., in the instances that
you
: > described. In our case, I think your example of setting an IMG SRC to
an
: > ASP is exactly what we have, with multiple of these IMGs on one page.
: >
: > But, I guess I'm still unclear about when IIS/ASP will or will not
handle
: > these multiple requests in a "queuing" fashion vs. not in a queuing
: fashion.
: >
: > What exactly determines this? As I mentioned, the posts I've seen
vaguely
: > mention "in the same session", without clearly defining what they mean
by
: a
: > "session".
: >
: > Actually, the reason that I'm chasing all of this around is that we are
: > running IIS on a multiprocessor server. With the IE client firing
: multiple
: > requests to IIS, we thought that the multiple requests from IE would be
: > spread across the multiple processors.
: >
: > But on our production server, instead, for a given user operation at the
: > IE/client end, which, again, creates several HTTP requests to IIS, we're
: > seeing CPU activity on 1 CPU, then the next CPU, then the next CPU,
etc.,
: > until the user operation is complete.
: >
: > The conclusion we're coming to is that for some reason ASP on the
: production
: > server is not handling the multiple requests "in parallel", but rather
: > queuing the requests (we see the parallel processing on a different
: > multiprocessor server that we use for testing, but not on the production
: > machine).
: >
: > We just cannot figure out what is different between these 2 machines
that
: > would cause queuing the requests in one case, but not in the other.
: >
: > Thanks,
: > Jim
: >
: > "Sylvain Lafontaine" <sylvain aei ca (fill the blanks, no spam please)>
: > wrote in message news:O7***************@tk2msftngp13.phx.gbl...
: > > That's true since IIS 3.0 and there are occasions when you don't need
to
: > > make quick refresh to see it in action.
: > >
: > > For example, this is necessary when the IE is making simultaneous
: requests
: > > to the IIS. Exemple of this are when you are dividing your page using
: > > Frameset: each frame contains one HTML page as its source. Refreshing
a
: > > frameset then require to ask the server for more than one HTML page.
: > >
: > > Another example is when the source of an objet is an ASP page, like
: this:
: > >
: > > <img src="get_the_image.asp">
: > >
: > > The use of Javascript and of other advanced facilities for requesting
: data
: > > from one or more ASP pages also rise the possibilities of having
: multiple
: > > simultaneous requests to the web server. It is clear from those
example
: > > that the server cannot run these requests in parallele because of the
: > > possibility that the codes inside theses pages can make contradictory
: > > changes to Session variables, global variables and/or other objects,
: like
: > > backend requests to a SQL-Server. This should clear any confusion
into
: > your
: > > mind.
: > >
: > > By the way, using things like WaitFor and others objets for timing in
: ASP
: > > can result in a severe degradation of performance from the IIS and
their
: > > usages must be reserved to the cases when they are strictly necessary.
: > >
: > > S. L.
: > >
: > > "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
: > > news:u0***************@TK2MSFTNGP11.phx.gbl...
: > > > Hi,
: > > >
: > > > I'm trying to understand a situation where ASP seems to be
"blocking"
: of
: > > > "queuing" requests. This is on a Win2K Advanced Server, with IIS5.
: > > >
: > > > I've seen some posts (e.g.,
: > > >
: > >
: >
:
http://groups.google.com/groups?hl=e...ngxa06.phx.gbl)
: > > > that indicate that ASP will queue up requests when they come in with
: the
: > > > same "session".
: > > >
: > > > My first question is "Can someone confirm that this is true?" (see
: > below).
: > > >
: > > > My second is regarding what "same session" means in this context?
: > > >
: > > > Several of the posts that I've seen with respect to this queuing
just
: > say
: > > > "session", but I've also seen some posts that say "ASP session", and
: > which
: > > > specifically mention "the ASP Session object". This latter
reference
: > > ("ASP
: > > > Session object") is more precise, but my testing (again, see below)
: > seems
: > > to
: > > > indicate that this interpretation of "session" is not "ASP Session
: > > object".
: > > >
: > > > Here's the test that tried:
: > > >
: > > > 1) I installed the Waitfor from ServerObjects
: > > > (http://www.serverobjects.com/products.htm), and created a small
: > > "text.txt"
: > > > file in c:\.
: > > >
: > > > 2) I put Waitfor.asp in my website.
: > > >
: > > > 3) I ran Performance Monitor and added the "Requests Queued" counter
: > > >
: > > > 4) Using IE, I went to http://myserver/waitfor.asp
: > > >
: > > > 5) Once it connected, I started clicking the IE Refresh button
: > > >
: > > >
: > > > As I clicked the IE Refresh button, I could see the "Requests
Queued"
: > > > counter climb in Performance Monitor.
: > > >
: > > > The above test SEEM to at least indicate that ASP will *INDEED* only
: > > process
: > > > a single request from IE, i.e., that ASP *IS* queuing, but I'm still
: > > > confused about under what circumstances this queuing will happen
(what
: > > does
: > > > "session" mean in this context?).
: > > >
: > > > Can someone clarify this?
: > > >
: > > > Thanks, and apologies for both the cross-post and somewhat long
: post...
: > > >
: > > >
: > >
: > >
: >
: >
:
:
Jul 19 '05 #5

P: n/a
Ken,

Thanks. I think that I understood that scenario (two IE instances), but if
I just run one IE instance and load a HTML page with, say, 2 IMG tags, e.g.:

<IMG SRC="/test.asp">
<IMG SRC="/test1.asp">

and I watch Performance Monitor "Requests Executing" and "Requests Queued",
I am seeing that sometimes the requests get queued (I can see "Requests
Queued" increment, then decrement), and sometimes they don't get queued. I
haven't been able to discern a pattern to this on my test system at home.
I've tried things like clearing the IE cache, setting IE to load pages every
time, etc., to no avail.

I'm really puzzled about why ASP is queuing requests sometime, and not
others on my system. If I could figure that out definitively, maybe it'd
give a hint about why I'm seeing queuing on 2 other systems, but not on one
other one :(...

Jim


"Ken Schaefer" <ke*******@THISadOpenStatic.com> wrote in message
news:OE****************@TK2MSFTNGP10.phx.gbl...
If you start a new instance of IE, then it does not share any in-memory
cookies (include ASP session state cookie) with the first IE instance. As
far as IIS is concerned, this is two separate ASP sessions. That is why you are probably seeing parallel processing.

Cheers
Ken

"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:ez****************@tk2msftngp13.phx.gbl...
: Sylvain,
:
: BTW, I forgot to mention:
:
: If I run my Waitfor test with 2 different instances of IE (on same
machine,
: but 2nd IE started from Start, not using Ctrl-N) simultaneously, I see
: Requests Executing in Perfmon as 2, i.e., in this situation, IIS *IS*
: apparently processing both requests simultaneously/in parallel.
:
: Like I said, I'm confused about what is different (specifically) between
the
: above test, and generating multiple HTTP requests from a single IE
: instance...
:
:
:
: "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
: news:Oi****************@TK2MSFTNGP11.phx.gbl...
: > Sylvain,
: >
: > Thanks for responding...
: >
: > Re. Waitfor, I just installed it for the test I described.
: >
: > Sorry if I'm being obtuse. I think I understand that one IE instance
can
: > generate multiple HTTP requests into IIS, e.g., in the instances that
you
: > described. In our case, I think your example of setting an IMG SRC to
an
: > ASP is exactly what we have, with multiple of these IMGs on one page.
: >
: > But, I guess I'm still unclear about when IIS/ASP will or will not
handle
: > these multiple requests in a "queuing" fashion vs. not in a queuing
: fashion.
: >
: > What exactly determines this? As I mentioned, the posts I've seen
vaguely
: > mention "in the same session", without clearly defining what they mean
by
: a
: > "session".
: >
: > Actually, the reason that I'm chasing all of this around is that we are : > running IIS on a multiprocessor server. With the IE client firing
: multiple
: > requests to IIS, we thought that the multiple requests from IE would be : > spread across the multiple processors.
: >
: > But on our production server, instead, for a given user operation at the : > IE/client end, which, again, creates several HTTP requests to IIS, we're : > seeing CPU activity on 1 CPU, then the next CPU, then the next CPU,
etc.,
: > until the user operation is complete.
: >
: > The conclusion we're coming to is that for some reason ASP on the
: production
: > server is not handling the multiple requests "in parallel", but rather
: > queuing the requests (we see the parallel processing on a different
: > multiprocessor server that we use for testing, but not on the production : > machine).
: >
: > We just cannot figure out what is different between these 2 machines
that
: > would cause queuing the requests in one case, but not in the other.
: >
: > Thanks,
: > Jim
: >
: > "Sylvain Lafontaine" <sylvain aei ca (fill the blanks, no spam please)> : > wrote in message news:O7***************@tk2msftngp13.phx.gbl...
: > > That's true since IIS 3.0 and there are occasions when you don't need to
: > > make quick refresh to see it in action.
: > >
: > > For example, this is necessary when the IE is making simultaneous
: requests
: > > to the IIS. Exemple of this are when you are dividing your page using : > > Frameset: each frame contains one HTML page as its source. Refreshing a
: > > frameset then require to ask the server for more than one HTML page.
: > >
: > > Another example is when the source of an objet is an ASP page, like
: this:
: > >
: > > <img src="get_the_image.asp">
: > >
: > > The use of Javascript and of other advanced facilities for requesting : data
: > > from one or more ASP pages also rise the possibilities of having
: multiple
: > > simultaneous requests to the web server. It is clear from those
example
: > > that the server cannot run these requests in parallele because of the : > > possibility that the codes inside theses pages can make contradictory : > > changes to Session variables, global variables and/or other objects,
: like
: > > backend requests to a SQL-Server. This should clear any confusion
into
: > your
: > > mind.
: > >
: > > By the way, using things like WaitFor and others objets for timing in : ASP
: > > can result in a severe degradation of performance from the IIS and
their
: > > usages must be reserved to the cases when they are strictly necessary. : > >
: > > S. L.
: > >
: > > "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
: > > news:u0***************@TK2MSFTNGP11.phx.gbl...
: > > > Hi,
: > > >
: > > > I'm trying to understand a situation where ASP seems to be
"blocking"
: of
: > > > "queuing" requests. This is on a Win2K Advanced Server, with IIS5. : > > >
: > > > I've seen some posts (e.g.,
: > > >
: > >
: >
:
http://groups.google.com/groups?hl=e...ngxa06.phx.gbl) : > > > that indicate that ASP will queue up requests when they come in with : the
: > > > same "session".
: > > >
: > > > My first question is "Can someone confirm that this is true?" (see
: > below).
: > > >
: > > > My second is regarding what "same session" means in this context?
: > > >
: > > > Several of the posts that I've seen with respect to this queuing
just
: > say
: > > > "session", but I've also seen some posts that say "ASP session", and : > which
: > > > specifically mention "the ASP Session object". This latter
reference
: > > ("ASP
: > > > Session object") is more precise, but my testing (again, see below) : > seems
: > > to
: > > > indicate that this interpretation of "session" is not "ASP Session
: > > object".
: > > >
: > > > Here's the test that tried:
: > > >
: > > > 1) I installed the Waitfor from ServerObjects
: > > > (http://www.serverobjects.com/products.htm), and created a small
: > > "text.txt"
: > > > file in c:\.
: > > >
: > > > 2) I put Waitfor.asp in my website.
: > > >
: > > > 3) I ran Performance Monitor and added the "Requests Queued" counter : > > >
: > > > 4) Using IE, I went to http://myserver/waitfor.asp
: > > >
: > > > 5) Once it connected, I started clicking the IE Refresh button
: > > >
: > > >
: > > > As I clicked the IE Refresh button, I could see the "Requests
Queued"
: > > > counter climb in Performance Monitor.
: > > >
: > > > The above test SEEM to at least indicate that ASP will *INDEED* only : > > process
: > > > a single request from IE, i.e., that ASP *IS* queuing, but I'm still : > > > confused about under what circumstances this queuing will happen
(what
: > > does
: > > > "session" mean in this context?).
: > > >
: > > > Can someone clarify this?
: > > >
: > > > Thanks, and apologies for both the cross-post and somewhat long
: post...
: > > >
: > > >
: > >
: > >
: >
: >
:
:

Jul 19 '05 #6

P: n/a
Hi All,

I think that I've made some progress, but I'm not quite sure if it's
backwards or forwards :(!

I tried testing with the keepalive (in IIS Manager) for the website
disabled/unchecked. With keepalive on the website disabled, I am seeing
consistently that when I start IE, then go to my test page, ASP is *ALWAYS*
not queuing. I then re-enabled keepalive on the website, and ASP queuing
went back to being inconsistent again.

Disabling keepalive might be ok, but I also found that if I tried to go to
the test page again after the 1st try, ASP would queue the requests :(.

Seems like I can't win :(...

Any other suggestions??

"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:uo****************@TK2MSFTNGP10.phx.gbl...
Ken,

Thanks. I think that I understood that scenario (two IE instances), but if I just run one IE instance and load a HTML page with, say, 2 IMG tags, e.g.:
<IMG SRC="/test.asp">
<IMG SRC="/test1.asp">

and I watch Performance Monitor "Requests Executing" and "Requests Queued", I am seeing that sometimes the requests get queued (I can see "Requests
Queued" increment, then decrement), and sometimes they don't get queued. I haven't been able to discern a pattern to this on my test system at home.
I've tried things like clearing the IE cache, setting IE to load pages every time, etc., to no avail.

I'm really puzzled about why ASP is queuing requests sometime, and not
others on my system. If I could figure that out definitively, maybe it'd
give a hint about why I'm seeing queuing on 2 other systems, but not on one other one :(...

Jim


"Ken Schaefer" <ke*******@THISadOpenStatic.com> wrote in message
news:OE****************@TK2MSFTNGP10.phx.gbl...
If you start a new instance of IE, then it does not share any in-memory
cookies (include ASP session state cookie) with the first IE instance. As far as IIS is concerned, this is two separate ASP sessions. That is why

you
are probably seeing parallel processing.

Cheers
Ken

"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:ez****************@tk2msftngp13.phx.gbl...
: Sylvain,
:
: BTW, I forgot to mention:
:
: If I run my Waitfor test with 2 different instances of IE (on same
machine,
: but 2nd IE started from Start, not using Ctrl-N) simultaneously, I see
: Requests Executing in Perfmon as 2, i.e., in this situation, IIS *IS*
: apparently processing both requests simultaneously/in parallel.
:
: Like I said, I'm confused about what is different (specifically) between the
: above test, and generating multiple HTTP requests from a single IE
: instance...
:
:
:
: "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
: news:Oi****************@TK2MSFTNGP11.phx.gbl...
: > Sylvain,
: >
: > Thanks for responding...
: >
: > Re. Waitfor, I just installed it for the test I described.
: >
: > Sorry if I'm being obtuse. I think I understand that one IE instance can
: > generate multiple HTTP requests into IIS, e.g., in the instances that you
: > described. In our case, I think your example of setting an IMG SRC to an
: > ASP is exactly what we have, with multiple of these IMGs on one page. : >
: > But, I guess I'm still unclear about when IIS/ASP will or will not
handle
: > these multiple requests in a "queuing" fashion vs. not in a queuing
: fashion.
: >
: > What exactly determines this? As I mentioned, the posts I've seen
vaguely
: > mention "in the same session", without clearly defining what they mean by
: a
: > "session".
: >
: > Actually, the reason that I'm chasing all of this around is that we

are
: > running IIS on a multiprocessor server. With the IE client firing
: multiple
: > requests to IIS, we thought that the multiple requests from IE would

be
: > spread across the multiple processors.
: >
: > But on our production server, instead, for a given user operation at

the
: > IE/client end, which, again, creates several HTTP requests to IIS,

we're
: > seeing CPU activity on 1 CPU, then the next CPU, then the next CPU,
etc.,
: > until the user operation is complete.
: >
: > The conclusion we're coming to is that for some reason ASP on the
: production
: > server is not handling the multiple requests "in parallel", but rather : > queuing the requests (we see the parallel processing on a different
: > multiprocessor server that we use for testing, but not on the

production
: > machine).
: >
: > We just cannot figure out what is different between these 2 machines
that
: > would cause queuing the requests in one case, but not in the other.
: >
: > Thanks,
: > Jim
: >
: > "Sylvain Lafontaine" <sylvain aei ca (fill the blanks, no spam

please)>
: > wrote in message news:O7***************@tk2msftngp13.phx.gbl...
: > > That's true since IIS 3.0 and there are occasions when you don't

need
to
: > > make quick refresh to see it in action.
: > >
: > > For example, this is necessary when the IE is making simultaneous
: requests
: > > to the IIS. Exemple of this are when you are dividing your page

using
: > > Frameset: each frame contains one HTML page as its source.

Refreshing
a
: > > frameset then require to ask the server for more than one HTML page. : > >
: > > Another example is when the source of an objet is an ASP page, like : this:
: > >
: > > <img src="get_the_image.asp">
: > >
: > > The use of Javascript and of other advanced facilities for

requesting
: data
: > > from one or more ASP pages also rise the possibilities of having
: multiple
: > > simultaneous requests to the web server. It is clear from those
example
: > > that the server cannot run these requests in parallele because of

the
: > > possibility that the codes inside theses pages can make

contradictory
: > > changes to Session variables, global variables and/or other objects, : like
: > > backend requests to a SQL-Server. This should clear any confusion
into
: > your
: > > mind.
: > >
: > > By the way, using things like WaitFor and others objets for timing

in
: ASP
: > > can result in a severe degradation of performance from the IIS and
their
: > > usages must be reserved to the cases when they are strictly

necessary.
: > >
: > > S. L.
: > >
: > > "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
: > > news:u0***************@TK2MSFTNGP11.phx.gbl...
: > > > Hi,
: > > >
: > > > I'm trying to understand a situation where ASP seems to be
"blocking"
: of
: > > > "queuing" requests. This is on a Win2K Advanced Server, with

IIS5.
: > > >
: > > > I've seen some posts (e.g.,
: > > >
: > >
: >
:

http://groups.google.com/groups?hl=e...ngxa06.phx.gbl)
: > > > that indicate that ASP will queue up requests when they come in

with
: the
: > > > same "session".
: > > >
: > > > My first question is "Can someone confirm that this is true?" (see : > below).
: > > >
: > > > My second is regarding what "same session" means in this context? : > > >
: > > > Several of the posts that I've seen with respect to this queuing
just
: > say
: > > > "session", but I've also seen some posts that say "ASP session",

and
: > which
: > > > specifically mention "the ASP Session object". This latter
reference
: > > ("ASP
: > > > Session object") is more precise, but my testing (again, see

below)
: > seems
: > > to
: > > > indicate that this interpretation of "session" is not "ASP Session : > > object".
: > > >
: > > > Here's the test that tried:
: > > >
: > > > 1) I installed the Waitfor from ServerObjects
: > > > (http://www.serverobjects.com/products.htm), and created a small
: > > "text.txt"
: > > > file in c:\.
: > > >
: > > > 2) I put Waitfor.asp in my website.
: > > >
: > > > 3) I ran Performance Monitor and added the "Requests Queued"

counter
: > > >
: > > > 4) Using IE, I went to http://myserver/waitfor.asp
: > > >
: > > > 5) Once it connected, I started clicking the IE Refresh button
: > > >
: > > >
: > > > As I clicked the IE Refresh button, I could see the "Requests
Queued"
: > > > counter climb in Performance Monitor.
: > > >
: > > > The above test SEEM to at least indicate that ASP will *INDEED*

only
: > > process
: > > > a single request from IE, i.e., that ASP *IS* queuing, but I'm

still
: > > > confused about under what circumstances this queuing will happen
(what
: > > does
: > > > "session" mean in this context?).
: > > >
: > > > Can someone clarify this?
: > > >
: > > > Thanks, and apologies for both the cross-post and somewhat long
: post...
: > > >
: > > >
: > >
: > >
: >
: >
:
:


Jul 19 '05 #7

P: n/a
Multiple requests to the same session will be executed consecutively, this
is by design and it's a necessity in case global variables (either stored
inside or outside the session) are to be accessed by both requests. The
fact that you have or not such access to shared variables is not relevant to
IIS, as it cannot see "in the future" what the code in your pages will do.

You can have what you want by using "sessionless" page; add the following
statement at the beginning of your pages:

%@LANGUAGE="VBSCRIPT" ENABLESESSIONSTATE="False" %

However, you won't have access to session variables, like Session("MyItem")
= myValue, with this. You can override this restriction by storing your
values elsewhere, like in a SQL-Server or in a QueryString.

The IIS which is giving you parallelism is probably set to use sessionless
by default or have its cookies disabled by some proxy. For the setting, I
cannot give you more information as I don't have access to a IIS5 or 6 right
now.

It is also that what you are seeing is some artifact, like activating
Hyperthreading or adding a second CPU after the Windows as been installed.
When you add a second CPU, you must remake a full installation of Windows or
use Sysprep to correctly activates it. With HT, I don't know if Sysprep is
sufficient.

It is also possible that some other process, like access to a SQL-Server, is
doing what you are seeing.

S. L.
.. What are you are seeing as paral
"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:er****************@tk2msftngp13.phx.gbl...
Hi All,

I think that I've made some progress, but I'm not quite sure if it's
backwards or forwards :(!

I tried testing with the keepalive (in IIS Manager) for the website
disabled/unchecked. With keepalive on the website disabled, I am seeing
consistently that when I start IE, then go to my test page, ASP is *ALWAYS* not queuing. I then re-enabled keepalive on the website, and ASP queuing
went back to being inconsistent again.

Disabling keepalive might be ok, but I also found that if I tried to go to
the test page again after the 1st try, ASP would queue the requests :(.

Seems like I can't win :(...

Any other suggestions??

"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:uo****************@TK2MSFTNGP10.phx.gbl...
Ken,

Thanks. I think that I understood that scenario (two IE instances), but if
I just run one IE instance and load a HTML page with, say, 2 IMG tags,

e.g.:

<IMG SRC="/test.asp">
<IMG SRC="/test1.asp">

and I watch Performance Monitor "Requests Executing" and "Requests

Queued",
I am seeing that sometimes the requests get queued (I can see "Requests
Queued" increment, then decrement), and sometimes they don't get queued.

I
haven't been able to discern a pattern to this on my test system at home.
I've tried things like clearing the IE cache, setting IE to load pages

every
time, etc., to no avail.

I'm really puzzled about why ASP is queuing requests sometime, and not
others on my system. If I could figure that out definitively, maybe it'd give a hint about why I'm seeing queuing on 2 other systems, but not on

one
other one :(...

Jim


"Ken Schaefer" <ke*******@THISadOpenStatic.com> wrote in message
news:OE****************@TK2MSFTNGP10.phx.gbl...
If you start a new instance of IE, then it does not share any in-memory cookies (include ASP session state cookie) with the first IE instance. As far as IIS is concerned, this is two separate ASP sessions. That is why you
are probably seeing parallel processing.

Cheers
Ken

"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:ez****************@tk2msftngp13.phx.gbl...
: Sylvain,
:
: BTW, I forgot to mention:
:
: If I run my Waitfor test with 2 different instances of IE (on same
machine,
: but 2nd IE started from Start, not using Ctrl-N) simultaneously, I
see : Requests Executing in Perfmon as 2, i.e., in this situation, IIS *IS* : apparently processing both requests simultaneously/in parallel.
:
: Like I said, I'm confused about what is different (specifically) between the
: above test, and generating multiple HTTP requests from a single IE
: instance...
:
:
:
: "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
: news:Oi****************@TK2MSFTNGP11.phx.gbl...
: > Sylvain,
: >
: > Thanks for responding...
: >
: > Re. Waitfor, I just installed it for the test I described.
: >
: > Sorry if I'm being obtuse. I think I understand that one IE instance can
: > generate multiple HTTP requests into IIS, e.g., in the instances that you
: > described. In our case, I think your example of setting an IMG SRC to
an
: > ASP is exactly what we have, with multiple of these IMGs on one page. : >
: > But, I guess I'm still unclear about when IIS/ASP will or will not
handle
: > these multiple requests in a "queuing" fashion vs. not in a
queuing : fashion.
: >
: > What exactly determines this? As I mentioned, the posts I've seen
vaguely
: > mention "in the same session", without clearly defining what they

mean by
: a
: > "session".
: >
: > Actually, the reason that I'm chasing all of this around is that we are
: > running IIS on a multiprocessor server. With the IE client firing
: multiple
: > requests to IIS, we thought that the multiple requests from IE
would
be
: > spread across the multiple processors.
: >
: > But on our production server, instead, for a given user operation
at the
: > IE/client end, which, again, creates several HTTP requests to IIS,

we're
: > seeing CPU activity on 1 CPU, then the next CPU, then the next
CPU, etc.,
: > until the user operation is complete.
: >
: > The conclusion we're coming to is that for some reason ASP on the
: production
: > server is not handling the multiple requests "in parallel", but

rather : > queuing the requests (we see the parallel processing on a different : > multiprocessor server that we use for testing, but not on the

production
: > machine).
: >
: > We just cannot figure out what is different between these 2 machines that
: > would cause queuing the requests in one case, but not in the other. : >
: > Thanks,
: > Jim
: >
: > "Sylvain Lafontaine" <sylvain aei ca (fill the blanks, no spam

please)>
: > wrote in message news:O7***************@tk2msftngp13.phx.gbl...
: > > That's true since IIS 3.0 and there are occasions when you don't

need
to
: > > make quick refresh to see it in action.
: > >
: > > For example, this is necessary when the IE is making simultaneous : requests
: > > to the IIS. Exemple of this are when you are dividing your page

using
: > > Frameset: each frame contains one HTML page as its source.

Refreshing
a
: > > frameset then require to ask the server for more than one HTML page. : > >
: > > Another example is when the source of an objet is an ASP page, like : this:
: > >
: > > <img src="get_the_image.asp">
: > >
: > > The use of Javascript and of other advanced facilities for

requesting
: data
: > > from one or more ASP pages also rise the possibilities of having
: multiple
: > > simultaneous requests to the web server. It is clear from those
example
: > > that the server cannot run these requests in parallele because of the
: > > possibility that the codes inside theses pages can make

contradictory
: > > changes to Session variables, global variables and/or other objects, : like
: > > backend requests to a SQL-Server. This should clear any
confusion into
: > your
: > > mind.
: > >
: > > By the way, using things like WaitFor and others objets for timing
in
: ASP
: > > can result in a severe degradation of performance from the IIS
and their
: > > usages must be reserved to the cases when they are strictly

necessary.
: > >
: > > S. L.
: > >
: > > "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
: > > news:u0***************@TK2MSFTNGP11.phx.gbl...
: > > > Hi,
: > > >
: > > > I'm trying to understand a situation where ASP seems to be
"blocking"
: of
: > > > "queuing" requests. This is on a Win2K Advanced Server, with

IIS5.
: > > >
: > > > I've seen some posts (e.g.,
: > > >
: > >
: >
:

http://groups.google.com/groups?hl=e...ngxa06.phx.gbl)
: > > > that indicate that ASP will queue up requests when they come in with
: the
: > > > same "session".
: > > >
: > > > My first question is "Can someone confirm that this is true?" (see : > below).
: > > >
: > > > My second is regarding what "same session" means in this context? : > > >
: > > > Several of the posts that I've seen with respect to this
queuing just
: > say
: > > > "session", but I've also seen some posts that say "ASP session",
and
: > which
: > > > specifically mention "the ASP Session object". This latter
reference
: > > ("ASP
: > > > Session object") is more precise, but my testing (again, see

below)
: > seems
: > > to
: > > > indicate that this interpretation of "session" is not "ASP Session : > > object".
: > > >
: > > > Here's the test that tried:
: > > >
: > > > 1) I installed the Waitfor from ServerObjects
: > > > (http://www.serverobjects.com/products.htm), and created a

small : > > "text.txt"
: > > > file in c:\.
: > > >
: > > > 2) I put Waitfor.asp in my website.
: > > >
: > > > 3) I ran Performance Monitor and added the "Requests Queued"

counter
: > > >
: > > > 4) Using IE, I went to http://myserver/waitfor.asp
: > > >
: > > > 5) Once it connected, I started clicking the IE Refresh button
: > > >
: > > >
: > > > As I clicked the IE Refresh button, I could see the "Requests
Queued"
: > > > counter climb in Performance Monitor.
: > > >
: > > > The above test SEEM to at least indicate that ASP will *INDEED* only
: > > process
: > > > a single request from IE, i.e., that ASP *IS* queuing, but I'm

still
: > > > confused about under what circumstances this queuing will

happen (what
: > > does
: > > > "session" mean in this context?).
: > > >
: > > > Can someone clarify this?
: > > >
: > > > Thanks, and apologies for both the cross-post and somewhat long : post...
: > > >
: > > >
: > >
: > >
: >
: >
:
:



Jul 19 '05 #8

P: n/a
Sylvain,

Thank you for this valuable information!!

After testing most of last night, I, too, am coming to the conclusion that
this "ASP queues requests" is normal behavior with IIS and ASP.

I'm thinking that the one system that we think is not queuing requests
actually is. I'm going to the test lab today to try a test this time with
Perfmon running as I did last night.

FYI, re. your comments, that system doesn't go through any proxies, and the
Device Manager shows "ACPI Multiproc", so I think it was installed with
multiprocessor support from the beginning. I'm not sure if cookies are
disabled.

Thanks again!

Jim

"Sylvain Lafontaine" <sylvain aei ca (fill the blanks, no spam please)>
wrote in message news:ez****************@TK2MSFTNGP09.phx.gbl...
Multiple requests to the same session will be executed consecutively, this
is by design and it's a necessity in case global variables (either stored
inside or outside the session) are to be accessed by both requests. The
fact that you have or not such access to shared variables is not relevant to IIS, as it cannot see "in the future" what the code in your pages will do.

You can have what you want by using "sessionless" page; add the following
statement at the beginning of your pages:

%@LANGUAGE="VBSCRIPT" ENABLESESSIONSTATE="False" %

However, you won't have access to session variables, like Session("MyItem") = myValue, with this. You can override this restriction by storing your
values elsewhere, like in a SQL-Server or in a QueryString.

The IIS which is giving you parallelism is probably set to use sessionless
by default or have its cookies disabled by some proxy. For the setting, I
cannot give you more information as I don't have access to a IIS5 or 6 right now.

It is also that what you are seeing is some artifact, like activating
Hyperthreading or adding a second CPU after the Windows as been installed.
When you add a second CPU, you must remake a full installation of Windows or use Sysprep to correctly activates it. With HT, I don't know if Sysprep is sufficient.

It is also possible that some other process, like access to a SQL-Server, is doing what you are seeing.

S. L.
. What are you are seeing as paral
"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:er****************@tk2msftngp13.phx.gbl...
Hi All,

I think that I've made some progress, but I'm not quite sure if it's
backwards or forwards :(!

I tried testing with the keepalive (in IIS Manager) for the website
disabled/unchecked. With keepalive on the website disabled, I am seeing
consistently that when I start IE, then go to my test page, ASP is *ALWAYS*
not queuing. I then re-enabled keepalive on the website, and ASP queuing
went back to being inconsistent again.

Disabling keepalive might be ok, but I also found that if I tried to go to the test page again after the 1st try, ASP would queue the requests :(.

Seems like I can't win :(...

Any other suggestions??

"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:uo****************@TK2MSFTNGP10.phx.gbl...
Ken,

Thanks. I think that I understood that scenario (two IE instances), but
if
I just run one IE instance and load a HTML page with, say, 2 IMG tags,

e.g.:

<IMG SRC="/test.asp">
<IMG SRC="/test1.asp">

and I watch Performance Monitor "Requests Executing" and "Requests

Queued",
I am seeing that sometimes the requests get queued (I can see
"Requests Queued" increment, then decrement), and sometimes they don't get queued. I
haven't been able to discern a pattern to this on my test system at home. I've tried things like clearing the IE cache, setting IE to load pages

every
time, etc., to no avail.

I'm really puzzled about why ASP is queuing requests sometime, and not
others on my system. If I could figure that out definitively, maybe

it'd give a hint about why I'm seeing queuing on 2 other systems, but not on one
other one :(...

Jim


"Ken Schaefer" <ke*******@THISadOpenStatic.com> wrote in message
news:OE****************@TK2MSFTNGP10.phx.gbl...
> If you start a new instance of IE, then it does not share any in-memory > cookies (include ASP session state cookie) with the first IE
instance.
As
> far as IIS is concerned, this is two separate ASP sessions. That is why you
> are probably seeing parallel processing.
>
> Cheers
> Ken
>
> "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
> news:ez****************@tk2msftngp13.phx.gbl...
> : Sylvain,
> :
> : BTW, I forgot to mention:
> :
> : If I run my Waitfor test with 2 different instances of IE (on same
> machine,
> : but 2nd IE started from Start, not using Ctrl-N) simultaneously, I see > : Requests Executing in Perfmon as 2, i.e., in this situation, IIS *IS* > : apparently processing both requests simultaneously/in parallel.
> :
> : Like I said, I'm confused about what is different (specifically)

between
> the
> : above test, and generating multiple HTTP requests from a single IE
> : instance...
> :
> :
> :
> : "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
> : news:Oi****************@TK2MSFTNGP11.phx.gbl...
> : > Sylvain,
> : >
> : > Thanks for responding...
> : >
> : > Re. Waitfor, I just installed it for the test I described.
> : >
> : > Sorry if I'm being obtuse. I think I understand that one IE

instance
> can
> : > generate multiple HTTP requests into IIS, e.g., in the instances

that
> you
> : > described. In our case, I think your example of setting an IMG SRC
to
> an
> : > ASP is exactly what we have, with multiple of these IMGs on one

page.
> : >
> : > But, I guess I'm still unclear about when IIS/ASP will or will

not > handle
> : > these multiple requests in a "queuing" fashion vs. not in a

queuing > : fashion.
> : >
> : > What exactly determines this? As I mentioned, the posts I've seen > vaguely
> : > mention "in the same session", without clearly defining what they mean
> by
> : a
> : > "session".
> : >
> : > Actually, the reason that I'm chasing all of this around is that we are
> : > running IIS on a multiprocessor server. With the IE client
firing > : multiple
> : > requests to IIS, we thought that the multiple requests from IE would be
> : > spread across the multiple processors.
> : >
> : > But on our production server, instead, for a given user operation at
the
> : > IE/client end, which, again, creates several HTTP requests to
IIS, we're
> : > seeing CPU activity on 1 CPU, then the next CPU, then the next

CPU, > etc.,
> : > until the user operation is complete.
> : >
> : > The conclusion we're coming to is that for some reason ASP on the > : production
> : > server is not handling the multiple requests "in parallel", but

rather
> : > queuing the requests (we see the parallel processing on a different > : > multiprocessor server that we use for testing, but not on the
production
> : > machine).
> : >
> : > We just cannot figure out what is different between these 2 machines > that
> : > would cause queuing the requests in one case, but not in the other. > : >
> : > Thanks,
> : > Jim
> : >
> : > "Sylvain Lafontaine" <sylvain aei ca (fill the blanks, no spam
please)>
> : > wrote in message news:O7***************@tk2msftngp13.phx.gbl...
> : > > That's true since IIS 3.0 and there are occasions when you don't need
> to
> : > > make quick refresh to see it in action.
> : > >
> : > > For example, this is necessary when the IE is making simultaneous > : requests
> : > > to the IIS. Exemple of this are when you are dividing your page using
> : > > Frameset: each frame contains one HTML page as its source.
Refreshing
> a
> : > > frameset then require to ask the server for more than one HTML

page.
> : > >
> : > > Another example is when the source of an objet is an ASP page,

like
> : this:
> : > >
> : > > <img src="get_the_image.asp">
> : > >
> : > > The use of Javascript and of other advanced facilities for
requesting
> : data
> : > > from one or more ASP pages also rise the possibilities of having > : multiple
> : > > simultaneous requests to the web server. It is clear from those > example
> : > > that the server cannot run these requests in parallele because of the
> : > > possibility that the codes inside theses pages can make
contradictory
> : > > changes to Session variables, global variables and/or other

objects,
> : like
> : > > backend requests to a SQL-Server. This should clear any confusion > into
> : > your
> : > > mind.
> : > >
> : > > By the way, using things like WaitFor and others objets for timing in
> : ASP
> : > > can result in a severe degradation of performance from the IIS and > their
> : > > usages must be reserved to the cases when they are strictly
necessary.
> : > >
> : > > S. L.
> : > >
> : > > "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
> : > > news:u0***************@TK2MSFTNGP11.phx.gbl...
> : > > > Hi,
> : > > >
> : > > > I'm trying to understand a situation where ASP seems to be
> "blocking"
> : of
> : > > > "queuing" requests. This is on a Win2K Advanced Server, with IIS5.
> : > > >
> : > > > I've seen some posts (e.g.,
> : > > >
> : > >
> : >
> :
>

http://groups.google.com/groups?hl=e...ngxa06.phx.gbl)
> : > > > that indicate that ASP will queue up requests when they come in with
> : the
> : > > > same "session".
> : > > >
> : > > > My first question is "Can someone confirm that this is true?" (see
> : > below).
> : > > >
> : > > > My second is regarding what "same session" means in this

context?
> : > > >
> : > > > Several of the posts that I've seen with respect to this queuing > just
> : > say
> : > > > "session", but I've also seen some posts that say "ASP session", and
> : > which
> : > > > specifically mention "the ASP Session object". This latter
> reference
> : > > ("ASP
> : > > > Session object") is more precise, but my testing (again, see
below)
> : > seems
> : > > to
> : > > > indicate that this interpretation of "session" is not "ASP

Session
> : > > object".
> : > > >
> : > > > Here's the test that tried:
> : > > >
> : > > > 1) I installed the Waitfor from ServerObjects
> : > > > (http://www.serverobjects.com/products.htm), and created a small > : > > "text.txt"
> : > > > file in c:\.
> : > > >
> : > > > 2) I put Waitfor.asp in my website.
> : > > >
> : > > > 3) I ran Performance Monitor and added the "Requests Queued"
counter
> : > > >
> : > > > 4) Using IE, I went to http://myserver/waitfor.asp
> : > > >
> : > > > 5) Once it connected, I started clicking the IE Refresh
button > : > > >
> : > > >
> : > > > As I clicked the IE Refresh button, I could see the "Requests > Queued"
> : > > > counter climb in Performance Monitor.
> : > > >
> : > > > The above test SEEM to at least indicate that ASP will

*INDEED* only
> : > > process
> : > > > a single request from IE, i.e., that ASP *IS* queuing, but I'm still
> : > > > confused about under what circumstances this queuing will happen > (what
> : > > does
> : > > > "session" mean in this context?).
> : > > >
> : > > > Can someone clarify this?
> : > > >
> : > > > Thanks, and apologies for both the cross-post and somewhat long > : post...
> : > > >
> : > > >
> : > >
> : > >
> : >
> : >
> :
> :
>
>



Jul 19 '05 #9

P: n/a
I easy mean to know for sure would be to store the beginning and ending time
of each request. Add some empty work, like adding 10000 times a letter to a
string, if necessary to increase the resolution beetween requests.

S. L.

"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:%2******************@TK2MSFTNGP09.phx.gbl...
Sylvain,

Thank you for this valuable information!!

After testing most of last night, I, too, am coming to the conclusion that
this "ASP queues requests" is normal behavior with IIS and ASP.

I'm thinking that the one system that we think is not queuing requests
actually is. I'm going to the test lab today to try a test this time with
Perfmon running as I did last night.

FYI, re. your comments, that system doesn't go through any proxies, and the Device Manager shows "ACPI Multiproc", so I think it was installed with
multiprocessor support from the beginning. I'm not sure if cookies are
disabled.

Thanks again!

Jim

"Sylvain Lafontaine" <sylvain aei ca (fill the blanks, no spam please)>
wrote in message news:ez****************@TK2MSFTNGP09.phx.gbl...
Multiple requests to the same session will be executed consecutively, this
is by design and it's a necessity in case global variables (either stored inside or outside the session) are to be accessed by both requests. The
fact that you have or not such access to shared variables is not relevant
to
IIS, as it cannot see "in the future" what the code in your pages will
do.
You can have what you want by using "sessionless" page; add the following statement at the beginning of your pages:

%@LANGUAGE="VBSCRIPT" ENABLESESSIONSTATE="False" %

However, you won't have access to session variables, like

Session("MyItem")
= myValue, with this. You can override this restriction by storing your
values elsewhere, like in a SQL-Server or in a QueryString.

The IIS which is giving you parallelism is probably set to use sessionless by default or have its cookies disabled by some proxy. For the setting, I cannot give you more information as I don't have access to a IIS5 or 6

right
now.

It is also that what you are seeing is some artifact, like activating
Hyperthreading or adding a second CPU after the Windows as been installed. When you add a second CPU, you must remake a full installation of Windows or
use Sysprep to correctly activates it. With HT, I don't know if Sysprep is
sufficient.

It is also possible that some other process, like access to a

SQL-Server, is
doing what you are seeing.

S. L.
. What are you are seeing as paral
"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:er****************@tk2msftngp13.phx.gbl...
Hi All,

I think that I've made some progress, but I'm not quite sure if it's
backwards or forwards :(!

I tried testing with the keepalive (in IIS Manager) for the website
disabled/unchecked. With keepalive on the website disabled, I am seeing consistently that when I start IE, then go to my test page, ASP is *ALWAYS*
not queuing. I then re-enabled keepalive on the website, and ASP

queuing went back to being inconsistent again.

Disabling keepalive might be ok, but I also found that if I tried to go to
the test page again after the 1st try, ASP would queue the requests
:(.
Seems like I can't win :(...

Any other suggestions??

"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:uo****************@TK2MSFTNGP10.phx.gbl...
> Ken,
>
> Thanks. I think that I understood that scenario (two IE instances),
but if
> I just run one IE instance and load a HTML page with, say, 2 IMG tags, e.g.:
>
> <IMG SRC="/test.asp">
> <IMG SRC="/test1.asp">
>
> and I watch Performance Monitor "Requests Executing" and "Requests
Queued",
> I am seeing that sometimes the requests get queued (I can see "Requests > Queued" increment, then decrement), and sometimes they don't get queued. I
> haven't been able to discern a pattern to this on my test system at

home.
> I've tried things like clearing the IE cache, setting IE to load pages every
> time, etc., to no avail.
>
> I'm really puzzled about why ASP is queuing requests sometime, and not
> others on my system. If I could figure that out definitively, maybe

it'd
> give a hint about why I'm seeing queuing on 2 other systems, but not on one
> other one :(...
>
> Jim
>
>
>
>
> "Ken Schaefer" <ke*******@THISadOpenStatic.com> wrote in message
> news:OE****************@TK2MSFTNGP10.phx.gbl...
> > If you start a new instance of IE, then it does not share any

in-memory
> > cookies (include ASP session state cookie) with the first IE instance. As
> > far as IIS is concerned, this is two separate ASP sessions. That
is why
> you
> > are probably seeing parallel processing.
> >
> > Cheers
> > Ken
> >
> > "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
> > news:ez****************@tk2msftngp13.phx.gbl...
> > : Sylvain,
> > :
> > : BTW, I forgot to mention:
> > :
> > : If I run my Waitfor test with 2 different instances of IE (on
same > > machine,
> > : but 2nd IE started from Start, not using Ctrl-N) simultaneously, I see
> > : Requests Executing in Perfmon as 2, i.e., in this situation, IIS

*IS*
> > : apparently processing both requests simultaneously/in parallel.
> > :
> > : Like I said, I'm confused about what is different (specifically)
between
> > the
> > : above test, and generating multiple HTTP requests from a single
IE > > : instance...
> > :
> > :
> > :
> > : "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
> > : news:Oi****************@TK2MSFTNGP11.phx.gbl...
> > : > Sylvain,
> > : >
> > : > Thanks for responding...
> > : >
> > : > Re. Waitfor, I just installed it for the test I described.
> > : >
> > : > Sorry if I'm being obtuse. I think I understand that one IE
instance
> > can
> > : > generate multiple HTTP requests into IIS, e.g., in the instances that
> > you
> > : > described. In our case, I think your example of setting an IMG SRC
to
> > an
> > : > ASP is exactly what we have, with multiple of these IMGs on
one page.
> > : >
> > : > But, I guess I'm still unclear about when IIS/ASP will or will

not > > handle
> > : > these multiple requests in a "queuing" fashion vs. not in a

queuing
> > : fashion.
> > : >
> > : > What exactly determines this? As I mentioned, the posts I've seen > > vaguely
> > : > mention "in the same session", without clearly defining what they mean
> > by
> > : a
> > : > "session".
> > : >
> > : > Actually, the reason that I'm chasing all of this around is that we
> are
> > : > running IIS on a multiprocessor server. With the IE client firing > > : multiple
> > : > requests to IIS, we thought that the multiple requests from IE

would
> be
> > : > spread across the multiple processors.
> > : >
> > : > But on our production server, instead, for a given user operation
at
> the
> > : > IE/client end, which, again, creates several HTTP requests to IIS, > we're
> > : > seeing CPU activity on 1 CPU, then the next CPU, then the next

CPU,
> > etc.,
> > : > until the user operation is complete.
> > : >
> > : > The conclusion we're coming to is that for some reason ASP on the > > : production
> > : > server is not handling the multiple requests "in parallel",
but rather
> > : > queuing the requests (we see the parallel processing on a

different
> > : > multiprocessor server that we use for testing, but not on the
> production
> > : > machine).
> > : >
> > : > We just cannot figure out what is different between these 2

machines
> > that
> > : > would cause queuing the requests in one case, but not in the

other.
> > : >
> > : > Thanks,
> > : > Jim
> > : >
> > : > "Sylvain Lafontaine" <sylvain aei ca (fill the blanks, no spam
> please)>
> > : > wrote in message news:O7***************@tk2msftngp13.phx.gbl... > > : > > That's true since IIS 3.0 and there are occasions when you

don't > need
> > to
> > : > > make quick refresh to see it in action.
> > : > >
> > : > > For example, this is necessary when the IE is making

simultaneous
> > : requests
> > : > > to the IIS. Exemple of this are when you are dividing your page > using
> > : > > Frameset: each frame contains one HTML page as its source.
> Refreshing
> > a
> > : > > frameset then require to ask the server for more than one HTML page.
> > : > >
> > : > > Another example is when the source of an objet is an ASP page, like
> > : this:
> > : > >
> > : > > <img src="get_the_image.asp">
> > : > >
> > : > > The use of Javascript and of other advanced facilities for
> requesting
> > : data
> > : > > from one or more ASP pages also rise the possibilities of having > > : multiple
> > : > > simultaneous requests to the web server. It is clear from those > > example
> > : > > that the server cannot run these requests in parallele because of
> the
> > : > > possibility that the codes inside theses pages can make
> contradictory
> > : > > changes to Session variables, global variables and/or other
objects,
> > : like
> > : > > backend requests to a SQL-Server. This should clear any

confusion
> > into
> > : > your
> > : > > mind.
> > : > >
> > : > > By the way, using things like WaitFor and others objets for

timing
> in
> > : ASP
> > : > > can result in a severe degradation of performance from the
IIS
and
> > their
> > : > > usages must be reserved to the cases when they are strictly
> necessary.
> > : > >
> > : > > S. L.
> > : > >
> > : > > "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
> > : > > news:u0***************@TK2MSFTNGP11.phx.gbl...
> > : > > > Hi,
> > : > > >
> > : > > > I'm trying to understand a situation where ASP seems to be
> > "blocking"
> > : of
> > : > > > "queuing" requests. This is on a Win2K Advanced Server, with > IIS5.
> > : > > >
> > : > > > I've seen some posts (e.g.,
> > : > > >
> > : > >
> > : >
> > :
> >
>

http://groups.google.com/groups?hl=e...ngxa06.phx.gbl) > > : > > > that indicate that ASP will queue up requests when they come in
> with
> > : the
> > : > > > same "session".
> > : > > >
> > : > > > My first question is "Can someone confirm that this is true?" (see
> > : > below).
> > : > > >
> > : > > > My second is regarding what "same session" means in this
context?
> > : > > >
> > : > > > Several of the posts that I've seen with respect to this

queuing
> > just
> > : > say
> > : > > > "session", but I've also seen some posts that say "ASP

session",
> and
> > : > which
> > : > > > specifically mention "the ASP Session object". This
latter > > reference
> > : > > ("ASP
> > : > > > Session object") is more precise, but my testing (again, see > below)
> > : > seems
> > : > > to
> > : > > > indicate that this interpretation of "session" is not "ASP
Session
> > : > > object".
> > : > > >
> > : > > > Here's the test that tried:
> > : > > >
> > : > > > 1) I installed the Waitfor from ServerObjects
> > : > > > (http://www.serverobjects.com/products.htm), and created a

small
> > : > > "text.txt"
> > : > > > file in c:\.
> > : > > >
> > : > > > 2) I put Waitfor.asp in my website.
> > : > > >
> > : > > > 3) I ran Performance Monitor and added the "Requests Queued" > counter
> > : > > >
> > : > > > 4) Using IE, I went to http://myserver/waitfor.asp
> > : > > >
> > : > > > 5) Once it connected, I started clicking the IE Refresh

button > > : > > >
> > : > > >
> > : > > > As I clicked the IE Refresh button, I could see the "Requests > > Queued"
> > : > > > counter climb in Performance Monitor.
> > : > > >
> > : > > > The above test SEEM to at least indicate that ASP will

*INDEED*
> only
> > : > > process
> > : > > > a single request from IE, i.e., that ASP *IS* queuing, but I'm > still
> > : > > > confused about under what circumstances this queuing will

happen
> > (what
> > : > > does
> > : > > > "session" mean in this context?).
> > : > > >
> > : > > > Can someone clarify this?
> > : > > >
> > : > > > Thanks, and apologies for both the cross-post and somewhat

long
> > : post...
> > : > > >
> > : > > >
> > : > >
> > : > >
> > : >
> > : >
> > :
> > :
> >
> >
>
>



Jul 19 '05 #10

P: n/a
Sylvain,

I did my testing, and it appears that even that machine that I thought
was not queuing requests is queuing requests.

I tried your suggestion (on another test machine) with an ASP site that
doesn't use the Session object, and disabled "session state". It's in
the "Configuration" for the website in IIS Manager, BTW.

Anyway, with "Enable session state" unchecked/disabled, I was able to
immediately see that "Requests Queued" stays at 0 all the time. I will
be talking to some applications guys to see if we can get away with not
using the Session object, and if we can, then we'll disable "session
state" on the website, and then, I think we should be "golden".

Sylvain, thanks for all your help. This has been VERY enlightening!

Jim

Sylvain Lafontaine wrote:

I easy mean to know for sure would be to store the beginning and ending time
of each request. Add some empty work, like adding 10000 times a letter to a
string, if necessary to increase the resolution beetween requests.

S. L.

"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:%2******************@TK2MSFTNGP09.phx.gbl...
Sylvain,

Thank you for this valuable information!!

After testing most of last night, I, too, am coming to the conclusion that
this "ASP queues requests" is normal behavior with IIS and ASP.

I'm thinking that the one system that we think is not queuing requests
actually is. I'm going to the test lab today to try a test this time with
Perfmon running as I did last night.

FYI, re. your comments, that system doesn't go through any proxies, and

the
Device Manager shows "ACPI Multiproc", so I think it was installed with
multiprocessor support from the beginning. I'm not sure if cookies are
disabled.

Thanks again!

Jim

"Sylvain Lafontaine" <sylvain aei ca (fill the blanks, no spam please)>
wrote in message news:ez****************@TK2MSFTNGP09.phx.gbl...
Multiple requests to the same session will be executed consecutively, this is by design and it's a necessity in case global variables (either stored inside or outside the session) are to be accessed by both requests. The
fact that you have or not such access to shared variables is not relevant
to
IIS, as it cannot see "in the future" what the code in your pages will

do.
You can have what you want by using "sessionless" page; add the following statement at the beginning of your pages:

%@LANGUAGE="VBSCRIPT" ENABLESESSIONSTATE="False" %

However, you won't have access to session variables, like

Session("MyItem")
= myValue, with this. You can override this restriction by storing your
values elsewhere, like in a SQL-Server or in a QueryString.

The IIS which is giving you parallelism is probably set to use sessionless by default or have its cookies disabled by some proxy. For the setting, I cannot give you more information as I don't have access to a IIS5 or 6

right
now.

It is also that what you are seeing is some artifact, like activating
Hyperthreading or adding a second CPU after the Windows as been installed. When you add a second CPU, you must remake a full installation of Windows
or
use Sysprep to correctly activates it. With HT, I don't know if Sysprep

is
sufficient.

It is also possible that some other process, like access to a

SQL-Server,
is
doing what you are seeing.

S. L.
. What are you are seeing as paral
"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:er****************@tk2msftngp13.phx.gbl...
> Hi All,
>
> I think that I've made some progress, but I'm not quite sure if it's
> backwards or forwards :(!
>
> I tried testing with the keepalive (in IIS Manager) for the website
> disabled/unchecked. With keepalive on the website disabled, I am

seeing > consistently that when I start IE, then go to my test page, ASP is
*ALWAYS*
> not queuing. I then re-enabled keepalive on the website, and ASP

queuing
> went back to being inconsistent again.
>
> Disabling keepalive might be ok, but I also found that if I tried to go
to
> the test page again after the 1st try, ASP would queue the requests

:(. >
> Seems like I can't win :(...
>
> Any other suggestions??
>
>
>
> "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
> news:uo****************@TK2MSFTNGP10.phx.gbl...
> > Ken,
> >
> > Thanks. I think that I understood that scenario (two IE instances),

but
> if
> > I just run one IE instance and load a HTML page with, say, 2 IMG tags, > e.g.:
> >
> > <IMG SRC="/test.asp">
> > <IMG SRC="/test1.asp">
> >
> > and I watch Performance Monitor "Requests Executing" and "Requests
> Queued",
> > I am seeing that sometimes the requests get queued (I can see

"Requests
> > Queued" increment, then decrement), and sometimes they don't get

queued.
> I
> > haven't been able to discern a pattern to this on my test system at
home.
> > I've tried things like clearing the IE cache, setting IE to load pages > every
> > time, etc., to no avail.
> >
> > I'm really puzzled about why ASP is queuing requests sometime, and not
> > others on my system. If I could figure that out definitively, maybe
it'd
> > give a hint about why I'm seeing queuing on 2 other systems, but not

on
> one
> > other one :(...
> >
> > Jim
> >
> >
> >
> >
> > "Ken Schaefer" <ke*******@THISadOpenStatic.com> wrote in message
> > news:OE****************@TK2MSFTNGP10.phx.gbl...
> > > If you start a new instance of IE, then it does not share any
in-memory
> > > cookies (include ASP session state cookie) with the first IE

instance.
> As
> > > far as IIS is concerned, this is two separate ASP sessions. That

is why
> > you
> > > are probably seeing parallel processing.
> > >
> > > Cheers
> > > Ken
> > >
> > > "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
> > > news:ez****************@tk2msftngp13.phx.gbl...
> > > : Sylvain,
> > > :
> > > : BTW, I forgot to mention:
> > > :
> > > : If I run my Waitfor test with 2 different instances of IE (on same > > > machine,
> > > : but 2nd IE started from Start, not using Ctrl-N) simultaneously, I see
> > > : Requests Executing in Perfmon as 2, i.e., in this situation, IIS
*IS*
> > > : apparently processing both requests simultaneously/in parallel.
> > > :
> > > : Like I said, I'm confused about what is different (specifically)
> between
> > > the
> > > : above test, and generating multiple HTTP requests from a single IE > > > : instance...
> > > :
> > > :
> > > :
> > > : "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
> > > : news:Oi****************@TK2MSFTNGP11.phx.gbl...
> > > : > Sylvain,
> > > : >
> > > : > Thanks for responding...
> > > : >
> > > : > Re. Waitfor, I just installed it for the test I described.
> > > : >
> > > : > Sorry if I'm being obtuse. I think I understand that one IE
> instance
> > > can
> > > : > generate multiple HTTP requests into IIS, e.g., in the instances > that
> > > you
> > > : > described. In our case, I think your example of setting an IMG SRC
> to
> > > an
> > > : > ASP is exactly what we have, with multiple of these IMGs on one > page.
> > > : >
> > > : > But, I guess I'm still unclear about when IIS/ASP will or will

not
> > > handle
> > > : > these multiple requests in a "queuing" fashion vs. not in a
queuing
> > > : fashion.
> > > : >
> > > : > What exactly determines this? As I mentioned, the posts I've

seen
> > > vaguely
> > > : > mention "in the same session", without clearly defining what

they
> mean
> > > by
> > > : a
> > > : > "session".
> > > : >
> > > : > Actually, the reason that I'm chasing all of this around is that we
> > are
> > > : > running IIS on a multiprocessor server. With the IE client

firing
> > > : multiple
> > > : > requests to IIS, we thought that the multiple requests from IE
would
> > be
> > > : > spread across the multiple processors.
> > > : >
> > > : > But on our production server, instead, for a given user

operation
at
> > the
> > > : > IE/client end, which, again, creates several HTTP requests to

IIS,
> > we're
> > > : > seeing CPU activity on 1 CPU, then the next CPU, then the next
CPU,
> > > etc.,
> > > : > until the user operation is complete.
> > > : >
> > > : > The conclusion we're coming to is that for some reason ASP on

the
> > > : production
> > > : > server is not handling the multiple requests "in parallel", but > rather
> > > : > queuing the requests (we see the parallel processing on a
different
> > > : > multiprocessor server that we use for testing, but not on the
> > production
> > > : > machine).
> > > : >
> > > : > We just cannot figure out what is different between these 2
machines
> > > that
> > > : > would cause queuing the requests in one case, but not in the
other.
> > > : >
> > > : > Thanks,
> > > : > Jim
> > > : >
> > > : > "Sylvain Lafontaine" <sylvain aei ca (fill the blanks, no spam
> > please)>
> > > : > wrote in message news:O7***************@tk2msftngp13.phx.gbl... > > > : > > That's true since IIS 3.0 and there are occasions when you

don't
> > need
> > > to
> > > : > > make quick refresh to see it in action.
> > > : > >
> > > : > > For example, this is necessary when the IE is making
simultaneous
> > > : requests
> > > : > > to the IIS. Exemple of this are when you are dividing your

page
> > using
> > > : > > Frameset: each frame contains one HTML page as its source.
> > Refreshing
> > > a
> > > : > > frameset then require to ask the server for more than one HTML > page.
> > > : > >
> > > : > > Another example is when the source of an objet is an ASP page, > like
> > > : this:
> > > : > >
> > > : > > <img src="get_the_image.asp">
> > > : > >
> > > : > > The use of Javascript and of other advanced facilities for
> > requesting
> > > : data
> > > : > > from one or more ASP pages also rise the possibilities of

having
> > > : multiple
> > > : > > simultaneous requests to the web server. It is clear from

those
> > > example
> > > : > > that the server cannot run these requests in parallele because of
> > the
> > > : > > possibility that the codes inside theses pages can make
> > contradictory
> > > : > > changes to Session variables, global variables and/or other
> objects,
> > > : like
> > > : > > backend requests to a SQL-Server. This should clear any
confusion
> > > into
> > > : > your
> > > : > > mind.
> > > : > >
> > > : > > By the way, using things like WaitFor and others objets for
timing
> > in
> > > : ASP
> > > : > > can result in a severe degradation of performance from the IIS and
> > > their
> > > : > > usages must be reserved to the cases when they are strictly
> > necessary.
> > > : > >
> > > : > > S. L.
> > > : > >
> > > : > > "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
> > > : > > news:u0***************@TK2MSFTNGP11.phx.gbl...
> > > : > > > Hi,
> > > : > > >
> > > : > > > I'm trying to understand a situation where ASP seems to be
> > > "blocking"
> > > : of
> > > : > > > "queuing" requests. This is on a Win2K Advanced Server,

with
> > IIS5.
> > > : > > >
> > > : > > > I've seen some posts (e.g.,
> > > : > > >
> > > : > >
> > > : >
> > > :
> > >
> >
>

http://groups.google.com/groups?hl=e...ngxa06.phx.gbl)
> > > : > > > that indicate that ASP will queue up requests when they come in
> > with
> > > : the
> > > : > > > same "session".
> > > : > > >
> > > : > > > My first question is "Can someone confirm that this is

true?"
> (see
> > > : > below).
> > > : > > >
> > > : > > > My second is regarding what "same session" means in this
> context?
> > > : > > >
> > > : > > > Several of the posts that I've seen with respect to this
queuing
> > > just
> > > : > say
> > > : > > > "session", but I've also seen some posts that say "ASP
session",
> > and
> > > : > which
> > > : > > > specifically mention "the ASP Session object". This latter > > > reference
> > > : > > ("ASP
> > > : > > > Session object") is more precise, but my testing (again, see > > below)
> > > : > seems
> > > : > > to
> > > : > > > indicate that this interpretation of "session" is not "ASP
> Session
> > > : > > object".
> > > : > > >
> > > : > > > Here's the test that tried:
> > > : > > >
> > > : > > > 1) I installed the Waitfor from ServerObjects
> > > : > > > (http://www.serverobjects.com/products.htm), and created a
small
> > > : > > "text.txt"
> > > : > > > file in c:\.
> > > : > > >
> > > : > > > 2) I put Waitfor.asp in my website.
> > > : > > >
> > > : > > > 3) I ran Performance Monitor and added the "Requests Queued" > > counter
> > > : > > >
> > > : > > > 4) Using IE, I went to http://myserver/waitfor.asp
> > > : > > >
> > > : > > > 5) Once it connected, I started clicking the IE Refresh

button
> > > : > > >
> > > : > > >
> > > : > > > As I clicked the IE Refresh button, I could see the

"Requests
> > > Queued"
> > > : > > > counter climb in Performance Monitor.
> > > : > > >
> > > : > > > The above test SEEM to at least indicate that ASP will
*INDEED*
> > only
> > > : > > process
> > > : > > > a single request from IE, i.e., that ASP *IS* queuing, but

I'm
> > still
> > > : > > > confused about under what circumstances this queuing will
happen
> > > (what
> > > : > > does
> > > : > > > "session" mean in this context?).
> > > : > > >
> > > : > > > Can someone clarify this?
> > > : > > >
> > > : > > > Thanks, and apologies for both the cross-post and somewhat
long
> > > : post...
> > > : > > >
> > > : > > >
> > > : > >
> > > : > >
> > > : >
> > > : >
> > > :
> > > :
> > >
> > >
> >
> >
>
>


Jul 19 '05 #11

P: n/a
By using the statement <%@ ENABLESESSIONSTATE="False" %>, you can disable
the Session state on a per page basis and you can use a mix of state and
stateless pages for your site without any particular problem.

S. L.
"Ohaya" <ohaya@N_O_S_P_A_M_cox.net> wrote in message
news:403CE7B5.52D0562A@N_O_S_P_A_M_cox.net...
Sylvain,

I did my testing, and it appears that even that machine that I thought
was not queuing requests is queuing requests.

I tried your suggestion (on another test machine) with an ASP site that
doesn't use the Session object, and disabled "session state". It's in
the "Configuration" for the website in IIS Manager, BTW.

Anyway, with "Enable session state" unchecked/disabled, I was able to
immediately see that "Requests Queued" stays at 0 all the time. I will
be talking to some applications guys to see if we can get away with not
using the Session object, and if we can, then we'll disable "session
state" on the website, and then, I think we should be "golden".

Sylvain, thanks for all your help. This has been VERY enlightening!

Jim

Sylvain Lafontaine wrote:

I easy mean to know for sure would be to store the beginning and ending time
of each request. Add some empty work, like adding 10000 times a letter to a string, if necessary to increase the resolution beetween requests.

S. L.

"Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
news:%2******************@TK2MSFTNGP09.phx.gbl...
Sylvain,

Thank you for this valuable information!!

After testing most of last night, I, too, am coming to the conclusion that this "ASP queues requests" is normal behavior with IIS and ASP.

I'm thinking that the one system that we think is not queuing requests
actually is. I'm going to the test lab today to try a test this time with Perfmon running as I did last night.

FYI, re. your comments, that system doesn't go through any proxies, and
the
Device Manager shows "ACPI Multiproc", so I think it was installed
with multiprocessor support from the beginning. I'm not sure if cookies are disabled.

Thanks again!

Jim

"Sylvain Lafontaine" <sylvain aei ca (fill the blanks, no spam please)> wrote in message news:ez****************@TK2MSFTNGP09.phx.gbl...
> Multiple requests to the same session will be executed consecutively, this
> is by design and it's a necessity in case global variables (either

stored
> inside or outside the session) are to be accessed by both requests.
The > fact that you have or not such access to shared variables is not

relevant
to
> IIS, as it cannot see "in the future" what the code in your pages will do.
>
> You can have what you want by using "sessionless" page; add the

following
> statement at the beginning of your pages:
>
> %@LANGUAGE="VBSCRIPT" ENABLESESSIONSTATE="False" %
>
> However, you won't have access to session variables, like
Session("MyItem")
> = myValue, with this. You can override this restriction by storing
your > values elsewhere, like in a SQL-Server or in a QueryString.
>
> The IIS which is giving you parallelism is probably set to use

sessionless
> by default or have its cookies disabled by some proxy. For the setting, I
> cannot give you more information as I don't have access to a IIS5 or
6 right
> now.
>
> It is also that what you are seeing is some artifact, like activating > Hyperthreading or adding a second CPU after the Windows as been

installed.
> When you add a second CPU, you must remake a full installation of

Windows
or
> use Sysprep to correctly activates it. With HT, I don't know if Sysprep is
> sufficient.
>
> It is also possible that some other process, like access to a

SQL-Server,
is
> doing what you are seeing.
>
> S. L.
>
>
> . What are you are seeing as paral
> "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
> news:er****************@tk2msftngp13.phx.gbl...
> > Hi All,
> >
> > I think that I've made some progress, but I'm not quite sure if it's > > backwards or forwards :(!
> >
> > I tried testing with the keepalive (in IIS Manager) for the website > > disabled/unchecked. With keepalive on the website disabled, I am

seeing
> > consistently that when I start IE, then go to my test page, ASP is
> *ALWAYS*
> > not queuing. I then re-enabled keepalive on the website, and ASP
queuing
> > went back to being inconsistent again.
> >
> > Disabling keepalive might be ok, but I also found that if I tried to go
to
> > the test page again after the 1st try, ASP would queue the
requests :(.
> >
> > Seems like I can't win :(...
> >
> > Any other suggestions??
> >
> >
> >
> > "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
> > news:uo****************@TK2MSFTNGP10.phx.gbl...
> > > Ken,
> > >
> > > Thanks. I think that I understood that scenario (two IE
instances), but
> > if
> > > I just run one IE instance and load a HTML page with, say, 2 IMG

tags,
> > e.g.:
> > >
> > > <IMG SRC="/test.asp">
> > > <IMG SRC="/test1.asp">
> > >
> > > and I watch Performance Monitor "Requests Executing" and "Requests > > Queued",
> > > I am seeing that sometimes the requests get queued (I can see
"Requests
> > > Queued" increment, then decrement), and sometimes they don't get
queued.
> > I
> > > haven't been able to discern a pattern to this on my test system at > home.
> > > I've tried things like clearing the IE cache, setting IE to load

pages
> > every
> > > time, etc., to no avail.
> > >
> > > I'm really puzzled about why ASP is queuing requests sometime, and not

> > > others on my system. If I could figure that out definitively,
maybe > it'd
> > > give a hint about why I'm seeing queuing on 2 other systems, but not on
> > one
> > > other one :(...
> > >
> > > Jim
> > >
> > >
> > >
> > >
> > > "Ken Schaefer" <ke*******@THISadOpenStatic.com> wrote in message
> > > news:OE****************@TK2MSFTNGP10.phx.gbl...
> > > > If you start a new instance of IE, then it does not share any
> in-memory
> > > > cookies (include ASP session state cookie) with the first IE
instance.
> > As
> > > > far as IIS is concerned, this is two separate ASP sessions. That is
> why
> > > you
> > > > are probably seeing parallel processing.
> > > >
> > > > Cheers
> > > > Ken
> > > >
> > > > "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
> > > > news:ez****************@tk2msftngp13.phx.gbl...
> > > > : Sylvain,
> > > > :
> > > > : BTW, I forgot to mention:
> > > > :
> > > > : If I run my Waitfor test with 2 different instances of IE
(on same
> > > > machine,
> > > > : but 2nd IE started from Start, not using Ctrl-N)
simultaneously, I
> see
> > > > : Requests Executing in Perfmon as 2, i.e., in this situation,
IIS > *IS*
> > > > : apparently processing both requests simultaneously/in parallel. > > > > :
> > > > : Like I said, I'm confused about what is different (specifically) > > between
> > > > the
> > > > : above test, and generating multiple HTTP requests from a single IE
> > > > : instance...
> > > > :
> > > > :
> > > > :
> > > > : "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
> > > > : news:Oi****************@TK2MSFTNGP11.phx.gbl...
> > > > : > Sylvain,
> > > > : >
> > > > : > Thanks for responding...
> > > > : >
> > > > : > Re. Waitfor, I just installed it for the test I described.
> > > > : >
> > > > : > Sorry if I'm being obtuse. I think I understand that one
IE > > instance
> > > > can
> > > > : > generate multiple HTTP requests into IIS, e.g., in the

instances
> > that
> > > > you
> > > > : > described. In our case, I think your example of setting an IMG
> SRC
> > to
> > > > an
> > > > : > ASP is exactly what we have, with multiple of these IMGs
on one
> > page.
> > > > : >
> > > > : > But, I guess I'm still unclear about when IIS/ASP will or
will not
> > > > handle
> > > > : > these multiple requests in a "queuing" fashion vs. not in a > queuing
> > > > : fashion.
> > > > : >
> > > > : > What exactly determines this? As I mentioned, the posts I've seen
> > > > vaguely
> > > > : > mention "in the same session", without clearly defining what they
> > mean
> > > > by
> > > > : a
> > > > : > "session".
> > > > : >
> > > > : > Actually, the reason that I'm chasing all of this around is that
> we
> > > are
> > > > : > running IIS on a multiprocessor server. With the IE
client firing
> > > > : multiple
> > > > : > requests to IIS, we thought that the multiple requests from IE > would
> > > be
> > > > : > spread across the multiple processors.
> > > > : >
> > > > : > But on our production server, instead, for a given user
operation
> at
> > > the
> > > > : > IE/client end, which, again, creates several HTTP requests to IIS,
> > > we're
> > > > : > seeing CPU activity on 1 CPU, then the next CPU, then the next > CPU,
> > > > etc.,
> > > > : > until the user operation is complete.
> > > > : >
> > > > : > The conclusion we're coming to is that for some reason ASP on the
> > > > : production
> > > > : > server is not handling the multiple requests "in parallel", but
> > rather
> > > > : > queuing the requests (we see the parallel processing on a
> different
> > > > : > multiprocessor server that we use for testing, but not on
the > > > production
> > > > : > machine).
> > > > : >
> > > > : > We just cannot figure out what is different between these 2 > machines
> > > > that
> > > > : > would cause queuing the requests in one case, but not in the > other.
> > > > : >
> > > > : > Thanks,
> > > > : > Jim
> > > > : >
> > > > : > "Sylvain Lafontaine" <sylvain aei ca (fill the blanks, no spam > > > please)>
> > > > : > wrote in message

news:O7***************@tk2msftngp13.phx.gbl...
> > > > : > > That's true since IIS 3.0 and there are occasions when you don't
> > > need
> > > > to
> > > > : > > make quick refresh to see it in action.
> > > > : > >
> > > > : > > For example, this is necessary when the IE is making
> simultaneous
> > > > : requests
> > > > : > > to the IIS. Exemple of this are when you are dividing your page
> > > using
> > > > : > > Frameset: each frame contains one HTML page as its source. > > > Refreshing
> > > > a
> > > > : > > frameset then require to ask the server for more than one HTML
> > page.
> > > > : > >
> > > > : > > Another example is when the source of an objet is an ASP

page,
> > like
> > > > : this:
> > > > : > >
> > > > : > > <img src="get_the_image.asp">
> > > > : > >
> > > > : > > The use of Javascript and of other advanced facilities
for > > > requesting
> > > > : data
> > > > : > > from one or more ASP pages also rise the possibilities of having
> > > > : multiple
> > > > : > > simultaneous requests to the web server. It is clear from those
> > > > example
> > > > : > > that the server cannot run these requests in parallele

because
> of
> > > the
> > > > : > > possibility that the codes inside theses pages can make
> > > contradictory
> > > > : > > changes to Session variables, global variables and/or other > > objects,
> > > > : like
> > > > : > > backend requests to a SQL-Server. This should clear any
> confusion
> > > > into
> > > > : > your
> > > > : > > mind.
> > > > : > >
> > > > : > > By the way, using things like WaitFor and others objets for > timing
> > > in
> > > > : ASP
> > > > : > > can result in a severe degradation of performance from the IIS
> and
> > > > their
> > > > : > > usages must be reserved to the cases when they are
strictly > > > necessary.
> > > > : > >
> > > > : > > S. L.
> > > > : > >
> > > > : > > "Ohaya" <Ohaya@NO_SPAM.cox.net> wrote in message
> > > > : > > news:u0***************@TK2MSFTNGP11.phx.gbl...
> > > > : > > > Hi,
> > > > : > > >
> > > > : > > > I'm trying to understand a situation where ASP seems to be > > > > "blocking"
> > > > : of
> > > > : > > > "queuing" requests. This is on a Win2K Advanced Server, with
> > > IIS5.
> > > > : > > >
> > > > : > > > I've seen some posts (e.g.,
> > > > : > > >
> > > > : > >
> > > > : >
> > > > :
> > > >
> > >
> >
>

http://groups.google.com/groups?hl=e...ngxa06.phx.gbl)
> > > > : > > > that indicate that ASP will queue up requests when they come
> in
> > > with
> > > > : the
> > > > : > > > same "session".
> > > > : > > >
> > > > : > > > My first question is "Can someone confirm that this is
true?"
> > (see
> > > > : > below).
> > > > : > > >
> > > > : > > > My second is regarding what "same session" means in
this > > context?
> > > > : > > >
> > > > : > > > Several of the posts that I've seen with respect to this > queuing
> > > > just
> > > > : > say
> > > > : > > > "session", but I've also seen some posts that say "ASP
> session",
> > > and
> > > > : > which
> > > > : > > > specifically mention "the ASP Session object". This

latter
> > > > reference
> > > > : > > ("ASP
> > > > : > > > Session object") is more precise, but my testing (again, see
> > > below)
> > > > : > seems
> > > > : > > to
> > > > : > > > indicate that this interpretation of "session" is not

"ASP > > Session
> > > > : > > object".
> > > > : > > >
> > > > : > > > Here's the test that tried:
> > > > : > > >
> > > > : > > > 1) I installed the Waitfor from ServerObjects
> > > > : > > > (http://www.serverobjects.com/products.htm), and created a > small
> > > > : > > "text.txt"
> > > > : > > > file in c:\.
> > > > : > > >
> > > > : > > > 2) I put Waitfor.asp in my website.
> > > > : > > >
> > > > : > > > 3) I ran Performance Monitor and added the "Requests

Queued"
> > > counter
> > > > : > > >
> > > > : > > > 4) Using IE, I went to http://myserver/waitfor.asp
> > > > : > > >
> > > > : > > > 5) Once it connected, I started clicking the IE Refresh button
> > > > : > > >
> > > > : > > >
> > > > : > > > As I clicked the IE Refresh button, I could see the
"Requests
> > > > Queued"
> > > > : > > > counter climb in Performance Monitor.
> > > > : > > >
> > > > : > > > The above test SEEM to at least indicate that ASP will
> *INDEED*
> > > only
> > > > : > > process
> > > > : > > > a single request from IE, i.e., that ASP *IS* queuing, but I'm
> > > still
> > > > : > > > confused about under what circumstances this queuing will > happen
> > > > (what
> > > > : > > does
> > > > : > > > "session" mean in this context?).
> > > > : > > >
> > > > : > > > Can someone clarify this?
> > > > : > > >
> > > > : > > > Thanks, and apologies for both the cross-post and somewhat > long
> > > > : post...
> > > > : > > >
> > > > : > > >
> > > > : > >
> > > > : > >
> > > > : >
> > > > : >
> > > > :
> > > > :
> > > >
> > > >
> > >
> > >
> >
> >
>
>

Jul 19 '05 #12

This discussion thread is closed

Replies have been disabled for this discussion.