We have an web application called I-CAL(Interactive Personal Loan
Calculator). This application is configured on server with Win 2000, IIS 5.0
and with 1 GB Ram.
The application is facing a very rare problem which is difficult to
reproduce and trace. The problem statement is as follows:

The application faces an ASP Error called "Type Mismatch" and the line it
points the error to is the statement where we create an Object of the
Business Component. For Eg: Set Obj = Server.CreateObject("PrgABC.clsXyz").
This is a very rare error which does'nt occur consistently. We are not able
to trace it also.
Can somemone tell me as to why we are facing such kind of error.
Note: It does'nt occur consistently.

The next error we are facing is "Exception Occured". This error basically
occurs when the number of users increases. At present the number of users
using the application are 350. But when the number increases to 500 the error
starts occuring. We have to restart the IIS to get some memory space. After
restarting, the application again start working smoothly.

We tried to simulate the same problem on Development Server by consuming the
memory space and then running the application. We were faced with the same
errors. May be it might be Memory problem or the problem might be becuase of
the large number of users accessing the site.

If any one could put some light on it that would be of great help.
Could any one help as the application is live and a lot chaos is created
when the users face such errors during peak hours. We have to restart the IIS
server which is not at all feasilble during such peak hours.

Any Soluion?????? Pleasssseeee.....

Thanks in advance for your valuable time and efforts.

Sameer Kulkarni.

Re: Type Mistmatch & Exception Occured Error by David

David
Thu Feb 23 04:28:29 CST 2006

Maybe your application simply has problems when under load or under memory
pressure. This is a very common failing pattern for web applications. It is
simply a problem within your application that the server cannot
fundamentally fix and has limited options to help. You resolve such issues
by either:
1. Fixing the application to be more robust
2. Figuring out when to restart the application during runtime

For example, you could write your ASP application to handle the failure to
Server.CreateObject() and send back either a custom error page or trigger a
recycle of IIS.

--
//David
IIS
http://blogs.msdn.com/David.Wang
This posting is provided "AS IS" with no warranties, and confers no rights.
//

"Sameer K" <Sameer K@discussions.microsoft.com> wrote in message
news:4DA7C4FF-F458-4ECA-8712-2A0AC6FC8715@microsoft.com...
> We have an web application called I-CAL(Interactive Personal Loan
> Calculator). This application is configured on server with Win 2000, IIS
> 5.0
> and with 1 GB Ram.
> The application is facing a very rare problem which is difficult to
> reproduce and trace. The problem statement is as follows:
>
> The application faces an ASP Error called "Type Mismatch" and the line it
> points the error to is the statement where we create an Object of the
> Business Component. For Eg: Set Obj =
> Server.CreateObject("PrgABC.clsXyz").
> This is a very rare error which does'nt occur consistently. We are not
> able
> to trace it also.
> Can somemone tell me as to why we are facing such kind of error.
> Note: It does'nt occur consistently.
>
> The next error we are facing is "Exception Occured". This error basically
> occurs when the number of users increases. At present the number of users
> using the application are 350. But when the number increases to 500 the
> error
> starts occuring. We have to restart the IIS to get some memory space.
> After
> restarting, the application again start working smoothly.
>
> We tried to simulate the same problem on Development Server by consuming
> the
> memory space and then running the application. We were faced with the same
> errors. May be it might be Memory problem or the problem might be becuase
> of
> the large number of users accessing the site.
>
> If any one could put some light on it that would be of great help.
> Could any one help as the application is live and a lot chaos is created
> when the users face such errors during peak hours. We have to restart the
> IIS
> server which is not at all feasilble during such peak hours.
>
> Any Soluion?????? Pleasssseeee.....
>
> Thanks in advance for your valuable time and efforts.
>
> Sameer Kulkarni.
>



Re: Type Mistmatch & Exception Occured Error by SameerK

SameerK
Wed Mar 01 02:37:28 CST 2006

Thanks David for your reply,

I would do the error handling as suggested by you to make my application
more robust. But first i want to know the reason why my application is
failing. Are these errors common in Web applications? If so then what are the
causes for such errors?

Please if you could give me some more exposure on this, that would be of
great help.

Regards,
Sameer Kulkarni.

"David Wang [Msft]" wrote:

> Maybe your application simply has problems when under load or under memory
> pressure. This is a very common failing pattern for web applications. It is
> simply a problem within your application that the server cannot
> fundamentally fix and has limited options to help. You resolve such issues
> by either:
> 1. Fixing the application to be more robust
> 2. Figuring out when to restart the application during runtime
>
> For example, you could write your ASP application to handle the failure to
> Server.CreateObject() and send back either a custom error page or trigger a
> recycle of IIS.
>
> --
> //David
> IIS
> http://blogs.msdn.com/David.Wang
> This posting is provided "AS IS" with no warranties, and confers no rights.
> //
>
> "Sameer K" <Sameer K@discussions.microsoft.com> wrote in message
> news:4DA7C4FF-F458-4ECA-8712-2A0AC6FC8715@microsoft.com...
> > We have an web application called I-CAL(Interactive Personal Loan
> > Calculator). This application is configured on server with Win 2000, IIS
> > 5.0
> > and with 1 GB Ram.
> > The application is facing a very rare problem which is difficult to
> > reproduce and trace. The problem statement is as follows:
> >
> > The application faces an ASP Error called "Type Mismatch" and the line it
> > points the error to is the statement where we create an Object of the
> > Business Component. For Eg: Set Obj =
> > Server.CreateObject("PrgABC.clsXyz").
> > This is a very rare error which does'nt occur consistently. We are not
> > able
> > to trace it also.
> > Can somemone tell me as to why we are facing such kind of error.
> > Note: It does'nt occur consistently.
> >
> > The next error we are facing is "Exception Occured". This error basically
> > occurs when the number of users increases. At present the number of users
> > using the application are 350. But when the number increases to 500 the
> > error
> > starts occuring. We have to restart the IIS to get some memory space.
> > After
> > restarting, the application again start working smoothly.
> >
> > We tried to simulate the same problem on Development Server by consuming
> > the
> > memory space and then running the application. We were faced with the same
> > errors. May be it might be Memory problem or the problem might be becuase
> > of
> > the large number of users accessing the site.
> >
> > If any one could put some light on it that would be of great help.
> > Could any one help as the application is live and a lot chaos is created
> > when the users face such errors during peak hours. We have to restart the
> > IIS
> > server which is not at all feasilble during such peak hours.
> >
> > Any Soluion?????? Pleasssseeee.....
> >
> > Thanks in advance for your valuable time and efforts.
> >
> > Sameer Kulkarni.
> >
>
>
>

Re: Type Mistmatch & Exception Occured Error by SameerK

SameerK
Wed Mar 01 05:11:27 CST 2006

Let me tell we are using Win 2000 server with IIS 5.0. The server has got 1GB
of RAM. There are no other applications running on it accept some which can
be neglected.

In the applications we are destroyiong objects wherever necessary.

Today also the users faced the same problem. The last time the users faced
the same problem was one month back. I was monitoring the server using
Performance tool and I found that the avilable memory was 13 MB when the
error occured. The number of anonymous users on server were 23.

Hope this information helps you in identifying the problem I'm facing and
you could be able to tell me what could be the cause?????

Could you tell me if these kind of errors are common in Web applications???
If so then what are the probable causes fot such errors.

Regards,
Sameer Kulkarni


"David Wang [Msft]" wrote:

> Maybe your application simply has problems when under load or under memory
> pressure. This is a very common failing pattern for web applications. It is
> simply a problem within your application that the server cannot
> fundamentally fix and has limited options to help. You resolve such issues
> by either:
> 1. Fixing the application to be more robust
> 2. Figuring out when to restart the application during runtime
>
> For example, you could write your ASP application to handle the failure to
> Server.CreateObject() and send back either a custom error page or trigger a
> recycle of IIS.
>
> --
> //David
> IIS
> http://blogs.msdn.com/David.Wang
> This posting is provided "AS IS" with no warranties, and confers no rights.
> //
>
> "Sameer K" <Sameer K@discussions.microsoft.com> wrote in message
> news:4DA7C4FF-F458-4ECA-8712-2A0AC6FC8715@microsoft.com...
> > We have an web application called I-CAL(Interactive Personal Loan
> > Calculator). This application is configured on server with Win 2000, IIS
> > 5.0
> > and with 1 GB Ram.
> > The application is facing a very rare problem which is difficult to
> > reproduce and trace. The problem statement is as follows:
> >
> > The application faces an ASP Error called "Type Mismatch" and the line it
> > points the error to is the statement where we create an Object of the
> > Business Component. For Eg: Set Obj =
> > Server.CreateObject("PrgABC.clsXyz").
> > This is a very rare error which does'nt occur consistently. We are not
> > able
> > to trace it also.
> > Can somemone tell me as to why we are facing such kind of error.
> > Note: It does'nt occur consistently.
> >
> > The next error we are facing is "Exception Occured". This error basically
> > occurs when the number of users increases. At present the number of users
> > using the application are 350. But when the number increases to 500 the
> > error
> > starts occuring. We have to restart the IIS to get some memory space.
> > After
> > restarting, the application again start working smoothly.
> >
> > We tried to simulate the same problem on Development Server by consuming
> > the
> > memory space and then running the application. We were faced with the same
> > errors. May be it might be Memory problem or the problem might be becuase
> > of
> > the large number of users accessing the site.
> >
> > If any one could put some light on it that would be of great help.
> > Could any one help as the application is live and a lot chaos is created
> > when the users face such errors during peak hours. We have to restart the
> > IIS
> > server which is not at all feasilble during such peak hours.
> >
> > Any Soluion?????? Pleasssseeee.....
> >
> > Thanks in advance for your valuable time and efforts.
> >
> > Sameer Kulkarni.
> >
>
>
>

Re: Type Mistmatch & Exception Occured Error by David

David
Wed Mar 01 06:37:55 CST 2006

Sounds like you are running code on the server which is leaking memory. Use
a tool like DebugDiag to help diagnose what is leaking memory and address
it. At this point, we only know you are low on memory but don't know what
has used up all the memory nor why. It requires debugging to figure out why.

http://www.microsoft.com/windowsserver2003/iis/diagnostictools/default.mspx

You should realize that this investigation only resolves the primary problem
(memory leak eventually preventing other components from instantiating). The
secondary problem is with your web application not handling this error
condition gracefully.

As for whether these kinds of errors are common in Web applications and
probable cause, I can only say:
1. Many people do not write code which handles error conditions (which
include stress, load, low memory) well
2. It is always possible to write code with logical flaws (called bugs)
which result in a variety of behaviors, including leaking memory
3. Humans make mistakes and never think of all possibilities
4. Computers are dumb and require explicit instructions for everything

Put them all together, and it should be clear that computer software, which
includes web applications, when written by humans are potentially full of
such unintentional logical flaws...

For example, when you say:
"In the applications we are destroyiong objects wherever necessary."

It does not mean it does not leak memory. In this case, it is easier to
diagnose the "smoking gun" to figure out what is leaking memory and go from
there.

--
//David
IIS
http://blogs.msdn.com/David.Wang
This posting is provided "AS IS" with no warranties, and confers no rights.
//

"Sameer K" <SameerK@discussions.microsoft.com> wrote in message
news:C217FA51-DF2F-4C9E-B256-DD6D345FB2F5@microsoft.com...
> Let me tell we are using Win 2000 server with IIS 5.0. The server has got
> 1GB
> of RAM. There are no other applications running on it accept some which
> can
> be neglected.
>
> In the applications we are destroyiong objects wherever necessary.
>
> Today also the users faced the same problem. The last time the users faced
> the same problem was one month back. I was monitoring the server using
> Performance tool and I found that the avilable memory was 13 MB when the
> error occured. The number of anonymous users on server were 23.
>
> Hope this information helps you in identifying the problem I'm facing and
> you could be able to tell me what could be the cause?????
>
> Could you tell me if these kind of errors are common in Web
> applications???
> If so then what are the probable causes fot such errors.
>
> Regards,
> Sameer Kulkarni
>
>
> "David Wang [Msft]" wrote:
>
>> Maybe your application simply has problems when under load or under
>> memory
>> pressure. This is a very common failing pattern for web applications. It
>> is
>> simply a problem within your application that the server cannot
>> fundamentally fix and has limited options to help. You resolve such
>> issues
>> by either:
>> 1. Fixing the application to be more robust
>> 2. Figuring out when to restart the application during runtime
>>
>> For example, you could write your ASP application to handle the failure
>> to
>> Server.CreateObject() and send back either a custom error page or trigger
>> a
>> recycle of IIS.
>>
>> --
>> //David
>> IIS
>> http://blogs.msdn.com/David.Wang
>> This posting is provided "AS IS" with no warranties, and confers no
>> rights.
>> //
>>
>> "Sameer K" <Sameer K@discussions.microsoft.com> wrote in message
>> news:4DA7C4FF-F458-4ECA-8712-2A0AC6FC8715@microsoft.com...
>> > We have an web application called I-CAL(Interactive Personal Loan
>> > Calculator). This application is configured on server with Win 2000,
>> > IIS
>> > 5.0
>> > and with 1 GB Ram.
>> > The application is facing a very rare problem which is difficult to
>> > reproduce and trace. The problem statement is as follows:
>> >
>> > The application faces an ASP Error called "Type Mismatch" and the line
>> > it
>> > points the error to is the statement where we create an Object of the
>> > Business Component. For Eg: Set Obj =
>> > Server.CreateObject("PrgABC.clsXyz").
>> > This is a very rare error which does'nt occur consistently. We are not
>> > able
>> > to trace it also.
>> > Can somemone tell me as to why we are facing such kind of error.
>> > Note: It does'nt occur consistently.
>> >
>> > The next error we are facing is "Exception Occured". This error
>> > basically
>> > occurs when the number of users increases. At present the number of
>> > users
>> > using the application are 350. But when the number increases to 500 the
>> > error
>> > starts occuring. We have to restart the IIS to get some memory space.
>> > After
>> > restarting, the application again start working smoothly.
>> >
>> > We tried to simulate the same problem on Development Server by
>> > consuming
>> > the
>> > memory space and then running the application. We were faced with the
>> > same
>> > errors. May be it might be Memory problem or the problem might be
>> > becuase
>> > of
>> > the large number of users accessing the site.
>> >
>> > If any one could put some light on it that would be of great help.
>> > Could any one help as the application is live and a lot chaos is
>> > created
>> > when the users face such errors during peak hours. We have to restart
>> > the
>> > IIS
>> > server which is not at all feasilble during such peak hours.
>> >
>> > Any Soluion?????? Pleasssseeee.....
>> >
>> > Thanks in advance for your valuable time and efforts.
>> >
>> > Sameer Kulkarni.
>> >
>>
>>
>>



Re: Type Mistmatch & Exception Occured Error by SameerK

SameerK
Fri Mar 17 06:06:27 CST 2006

Hi David,
Thanks for your help and suggestion. I had run the toolon the Production
Server and was able to create the report while the error occured.
But I'm not able to understand the report and make out some clue out of it.
If you could just help in understanding the report that would be of great
help.

I'm not able to paste the report here in this reply since its too long. Is
there any other way i could send you the report.

"David Wang [Msft]" wrote:

> Sounds like you are running code on the server which is leaking memory. Use
> a tool like DebugDiag to help diagnose what is leaking memory and address
> it. At this point, we only know you are low on memory but don't know what
> has used up all the memory nor why. It requires debugging to figure out why.
>
> http://www.microsoft.com/windowsserver2003/iis/diagnostictools/default.mspx
>
> You should realize that this investigation only resolves the primary problem
> (memory leak eventually preventing other components from instantiating). The
> secondary problem is with your web application not handling this error
> condition gracefully.
>
> As for whether these kinds of errors are common in Web applications and
> probable cause, I can only say:
> 1. Many people do not write code which handles error conditions (which
> include stress, load, low memory) well
> 2. It is always possible to write code with logical flaws (called bugs)
> which result in a variety of behaviors, including leaking memory
> 3. Humans make mistakes and never think of all possibilities
> 4. Computers are dumb and require explicit instructions for everything
>
> Put them all together, and it should be clear that computer software, which
> includes web applications, when written by humans are potentially full of
> such unintentional logical flaws...
>
> For example, when you say:
> "In the applications we are destroyiong objects wherever necessary."
>
> It does not mean it does not leak memory. In this case, it is easier to
> diagnose the "smoking gun" to figure out what is leaking memory and go from
> there.
>
> --
> //David
> IIS
> http://blogs.msdn.com/David.Wang
> This posting is provided "AS IS" with no warranties, and confers no rights.
> //
>
> "Sameer K" <SameerK@discussions.microsoft.com> wrote in message
> news:C217FA51-DF2F-4C9E-B256-DD6D345FB2F5@microsoft.com...
> > Let me tell we are using Win 2000 server with IIS 5.0. The server has got
> > 1GB
> > of RAM. There are no other applications running on it accept some which
> > can
> > be neglected.
> >
> > In the applications we are destroyiong objects wherever necessary.
> >
> > Today also the users faced the same problem. The last time the users faced
> > the same problem was one month back. I was monitoring the server using
> > Performance tool and I found that the avilable memory was 13 MB when the
> > error occured. The number of anonymous users on server were 23.
> >
> > Hope this information helps you in identifying the problem I'm facing and
> > you could be able to tell me what could be the cause?????
> >
> > Could you tell me if these kind of errors are common in Web
> > applications???
> > If so then what are the probable causes fot such errors.
> >
> > Regards,
> > Sameer Kulkarni
> >
> >
> > "David Wang [Msft]" wrote:
> >
> >> Maybe your application simply has problems when under load or under
> >> memory
> >> pressure. This is a very common failing pattern for web applications. It
> >> is
> >> simply a problem within your application that the server cannot
> >> fundamentally fix and has limited options to help. You resolve such
> >> issues
> >> by either:
> >> 1. Fixing the application to be more robust
> >> 2. Figuring out when to restart the application during runtime
> >>
> >> For example, you could write your ASP application to handle the failure
> >> to
> >> Server.CreateObject() and send back either a custom error page or trigger
> >> a
> >> recycle of IIS.
> >>
> >> --
> >> //David
> >> IIS
> >> http://blogs.msdn.com/David.Wang
> >> This posting is provided "AS IS" with no warranties, and c