Custom Http Handler Factory and Possible Concurrency Issues on Application Start

[Jordan S.]

Using .NET 3.5...

1. Will ASP.NET guarantee that no more than ONE instance of a custom HTTP
handler factory (class implementing IHttpHandlerFac tory) is ever created in
an ASP.NET application?

2. Assuming the answer to #1 is "yes - never more than one instance" (I hope
that's true), then does ASP.NET automatically take care of concurrency with
respect to accessing that one instance?

My situation is that I have written a custom handler factory. In it's
constructor, I initialize a couple of class-scoped collections that are
subsequently used by logic called by the factory's GetHandler() method.

I am concerned that when the app is restarted (for whatever reason), and if
the site is really busy, multiple requests could arrive simultaneously (or
close enough to cause concurrency problems) while my custom factory is
initializing itself. Is there anything I can or should do to avoid race
conditions or other such concurrency problems - or will ASP.NET queue the
requests until the factory is ready to serve all of the queued requests?

I have observed that my custom factory is not instantiated until the first
request arrives (after an IIS or application restart)... thus my concern -
what if 100 requests arrive all at once and the factory isn't yet
instantiated and initialized?

Thanks.

[Juan T. Llibre]

re:
!what if 100 requests arrive all at once

You mean if 100 requests arrive within the same 10,000th of one second ?
I'd find it very difficult to see that happening.

Juan T. Llibre, asp.net MVP
asp.net faq : http://asp.net.do/faq/
foros de asp.net, en español : http://asp.net.do/foros/
=============== =============== ========
"Jordan S." <[e-mail] in message news:et******** ******@TK2MSFTN GP04.phx.gbl...

Using .NET 3.5...

1. Will ASP.NET guarantee that no more than ONE instance of a custom HTTP handler factory (class implementing
IHttpHandlerFac tory) is ever created in an ASP.NET application?

2. Assuming the answer to #1 is "yes - never more than one instance" (I hope that's true), then does ASP.NET
automatically take care of concurrency with respect to accessing that one instance?

My situation is that I have written a custom handler factory. In it's constructor, I initialize a couple of
class-scoped collections that are subsequently used by logic called by the factory's GetHandler() method.

I am concerned that when the app is restarted (for whatever reason), and if the site is really busy, multiple requests
could arrive simultaneously (or close enough to cause concurrency problems) while my custom factory is initializing
itself. Is there anything I can or should do to avoid race conditions or other such concurrency problems - or will
ASP.NET queue the requests until the factory is ready to serve all of the queued requests?

I have observed that my custom factory is not instantiated until the first request arrives (after an IIS or
application restart)... thus my concern - what if 100 requests arrive all at once and the factory isn't yet
instantiated and initialized?

Thanks.

[Jordan S.]

The factory, upon startup (it being instantiated) hits the database. That's
a quick hit, but still it could be a full 1 second for the factory to fully
initialize itself.
It's reasonable to expect multiple requests to arrive within that one
second. Will those requests queue up nicely and wait for the factory to
initialize? Or would multiple instances of the factory be created?

-Jordan
"Juan T. Llibre" <no***********@ nowhere.comwrot e in message
news:e5******** ******@TK2MSFTN GP06.phx.gbl...

re:
!what if 100 requests arrive all at once

You mean if 100 requests arrive within the same 10,000th of one second ?
I'd find it very difficult to see that happening.

Juan T. Llibre, asp.net MVP
asp.net faq : http://asp.net.do/faq/
foros de asp.net, en español : http://asp.net.do/foros/
=============== =============== ========
"Jordan S." <[e-mail] in message
news:et******** ******@TK2MSFTN GP04.phx.gbl...

>Using .NET 3.5...

1. Will ASP.NET guarantee that no more than ONE instance of a custom HTTP
handler factory (class implementing IHttpHandlerFac tory) is ever created
in an ASP.NET application?

2. Assuming the answer to #1 is "yes - never more than one instance" (I
hope that's true), then does ASP.NET automatically take care of
concurrency with respect to accessing that one instance?

My situation is that I have written a custom handler factory. In it's
constructor, I initialize a couple of class-scoped collections that are
subsequently used by logic called by the factory's GetHandler() method.

I am concerned that when the app is restarted (for whatever reason), and
if the site is really busy, multiple requests could arrive simultaneously
(or close enough to cause concurrency problems) while my custom factory
is initializing itself. Is there anything I can or should do to avoid
race conditions or other such concurrency problems - or will ASP.NET
queue the requests until the factory is ready to serve all of the queued
requests?

I have observed that my custom factory is not instantiated until the
first request arrives (after an IIS or application restart)... thus my
concern - what if 100 requests arrive all at once and the factory isn't
yet instantiated and initialized?

Thanks.

[=?Utf-8?B?YnJ1Y2UgYmFya2Vy?=]

1. no. there is one instance per httpapplication instance. the actually
loading of the code is serialized. httpapplication are keep in pool

-- bruce (sqlwork.com)
"Jordan S." wrote:

Using .NET 3.5...

1. Will ASP.NET guarantee that no more than ONE instance of a custom HTTP
handler factory (class implementing IHttpHandlerFac tory) is ever created in
an ASP.NET application?

2. Assuming the answer to #1 is "yes - never more than one instance" (I hope
that's true), then does ASP.NET automatically take care of concurrency with
respect to accessing that one instance?

My situation is that I have written a custom handler factory. In it's
constructor, I initialize a couple of class-scoped collections that are
subsequently used by logic called by the factory's GetHandler() method.

I am concerned that when the app is restarted (for whatever reason), and if
the site is really busy, multiple requests could arrive simultaneously (or
close enough to cause concurrency problems) while my custom factory is
initializing itself. Is there anything I can or should do to avoid race
conditions or other such concurrency problems - or will ASP.NET queue the
requests until the factory is ready to serve all of the queued requests?

I have observed that my custom factory is not instantiated until the first
request arrives (after an IIS or application restart)... thus my concern -
what if 100 requests arrive all at once and the factory isn't yet
instantiated and initialized?

Thanks.

[Juan T. Llibre]

re:
!It's reasonable to expect multiple requests to arrive within that one second.

Sure, but the requests for code-loading are serialized.

Juan T. Llibre, asp.net MVP
asp.net faq : http://asp.net.do/faq/
foros de asp.net, en español : http://asp.net.do/foros/
=============== =============== ========
"Jordan S." <[e-mail] in message news:e5******** ******@TK2MSFTN GP06.phx.gbl...

The factory, upon startup (it being instantiated) hits the database. That's a quick hit, but still it could be a full
1 second for the factory to fully initialize itself.
It's reasonable to expect multiple requests to arrive within that one second. Will those requests queue up nicely and
wait for the factory to initialize? Or would multiple instances of the factory be created?

-Jordan
"Juan T. Llibre" <no***********@ nowhere.comwrot e in message news:e5******** ******@TK2MSFTN GP06.phx.gbl...

>re:
!what if 100 requests arrive all at once

You mean if 100 requests arrive within the same 10,000th of one second ?
I'd find it very difficult to see that happening.

Juan T. Llibre, asp.net MVP
asp.net faq : http://asp.net.do/faq/
foros de asp.net, en español : http://asp.net.do/foros/
============== =============== =========
"Jordan S." <[e-mail] in message news:et******** ******@TK2MSFTN GP04.phx.gbl...

>>Using .NET 3.5...

1. Will ASP.NET guarantee that no more than ONE instance of a custom HTTP handler factory (class implementing
IHttpHandlerF actory) is ever created in an ASP.NET application?

2. Assuming the answer to #1 is "yes - never more than one instance" (I hope that's true), then does ASP.NET
automatical ly take care of concurrency with respect to accessing that one instance?

My situation is that I have written a custom handler factory. In it's constructor, I initialize a couple of
class-scoped collections that are subsequently used by logic called by the factory's GetHandler() method.

I am concerned that when the app is restarted (for whatever reason), and if the site is really busy, multiple
requests could arrive simultaneously (or close enough to cause concurrency problems) while my custom factory is
initializin g itself. Is there anything I can or should do to avoid race conditions or other such concurrency
problems - or will ASP.NET queue the requests until the factory is ready to serve all of the queued requests?

I have observed that my custom factory is not instantiated until the first request arrives (after an IIS or
application restart)... thus my concern - what if 100 requests arrive all at once and the factory isn't yet
instantiate d and initialized?

Thanks.

[Jordan S.]

Thanks Juan.
"Juan T. Llibre" <no***********@ nowhere.comwrot e in message
news:eX******** ******@TK2MSFTN GP06.phx.gbl...

re:
!It's reasonable to expect multiple requests to arrive within that one
second.

Sure, but the requests for code-loading are serialized.

Juan T. Llibre, asp.net MVP
asp.net faq : http://asp.net.do/faq/
foros de asp.net, en español : http://asp.net.do/foros/
=============== =============== ========
"Jordan S." <[e-mail] in message
news:e5******** ******@TK2MSFTN GP06.phx.gbl...

>The factory, upon startup (it being instantiated) hits the database.
That's a quick hit, but still it could be a full 1 second for the factory
to fully initialize itself.
It's reasonable to expect multiple requests to arrive within that one
second. Will those requests queue up nicely and wait for the factory to
initialize? Or would multiple instances of the factory be created?

-Jordan
"Juan T. Llibre" <no***********@ nowhere.comwrot e in message
news:e5******* *******@TK2MSFT NGP06.phx.gbl.. .

>>re:
!what if 100 requests arrive all at once

You mean if 100 requests arrive within the same 10,000th of one second ?
I'd find it very difficult to see that happening.

Juan T. Llibre, asp.net MVP
asp.net faq : http://asp.net.do/faq/
foros de asp.net, en español : http://asp.net.do/foros/
============= =============== ==========
"Jordan S." <[e-mail] in message
news:et****** ********@TK2MSF TNGP04.phx.gbl. ..
Using .NET 3.5...

1. Will ASP.NET guarantee that no more than ONE instance of a custom
HTTP handler factory (class implementing IHttpHandlerFac tory) is ever
created in an ASP.NET application?

2. Assuming the answer to #1 is "yes - never more than one instance" (I
hope that's true), then does ASP.NET automatically take care of
concurrenc y with respect to accessing that one instance?

My situation is that I have written a custom handler factory. In it's
constructo r, I initialize a couple of class-scoped collections that are
subsequent ly used by logic called by the factory's GetHandler() method.

I am concerned that when the app is restarted (for whatever reason),
and if the site is really busy, multiple requests could arrive
simultaneous ly (or close enough to cause concurrency problems) while my
custom factory is initializing itself. Is there anything I can or
should do to avoid race conditions or other such concurrency problems -
or will ASP.NET queue the requests until the factory is ready to serve
all of the queued requests?

I have observed that my custom factory is not instantiated until the
first request arrives (after an IIS or application restart)... thus my
concern - what if 100 requests arrive all at once and the factory isn't
yet instantiated and initialized?

Thanks.

[Jordan S.]

Thanks Bruce.
"bruce barker" <br*********@di scussions.micro soft.comwrote in message
news:2E******** *************** ***********@mic rosoft.com...

1. no. there is one instance per httpapplication instance. the actually
loading of the code is serialized. httpapplication are keep in pool

-- bruce (sqlwork.com)
"Jordan S." wrote:

>Using .NET 3.5...

1. Will ASP.NET guarantee that no more than ONE instance of a custom HTTP
handler factory (class implementing IHttpHandlerFac tory) is ever created
in
an ASP.NET application?

2. Assuming the answer to #1 is "yes - never more than one instance" (I
hope
that's true), then does ASP.NET automatically take care of concurrency
with
respect to accessing that one instance?

My situation is that I have written a custom handler factory. In it's
constructor, I initialize a couple of class-scoped collections that are
subsequently used by logic called by the factory's GetHandler() method.

I am concerned that when the app is restarted (for whatever reason), and
if
the site is really busy, multiple requests could arrive simultaneously
(or
close enough to cause concurrency problems) while my custom factory is
initializing itself. Is there anything I can or should do to avoid race
conditions or other such concurrency problems - or will ASP.NET queue the
requests until the factory is ready to serve all of the queued requests?

I have observed that my custom factory is not instantiated until the
first
request arrives (after an IIS or application restart)... thus my
concern -
what if 100 requests arrive all at once and the factory isn't yet
instantiated and initialized?

Thanks.