aspnet server application hang for couple of minutes

[Guest]

What may be the reason for the following behavior:


There is an asp.net application. The application is quite complex.
Sometimes user request processing lasts long (even 1 ).

When user postbacks some data or enters the page for the first time, his
browser is not freezed. Whenever the user wants, he can stop, refresh or
go somewhere else, whilst the request is being processed.

And the problem now:
When the request is being processed, and the client refreshes his browser
(or requests something else, but still within the same application)
the requests instead of being processed get blocked. It looks as
if the server process has hung, and the browser is waiting for the response.
The response comes after 50-140 .
This happens only if user requests something, while his previous request
is still being processed.


What may be the reson for this strange behaviour ?
In my opinion, the server should queue the requests coming from the same
session
and process them. however the machine is idle, nothing happens for 1 minute.

To make things worse, not only _this_ client session freezes. If other guys
use the application, they also wait so long.

To make things even worse, this happens also to other asp.net applications
running in the context of the aspnet_wp.exe. Clients of those web applications
also do wait (only due to the fact that somebody has pressed browser refresh
button too frequently).

Help
Michal

 

[Mark Rae]

What may be the reason for the following behavior:

Are your pages interfacing with a back-end database? If so, might you be
running out of connections...?

 

[Guest]

Are your pages interfacing with a back-end database? If so, might you be
running out of connections...?

No. The pages do not use databases, nor do they use any other network
resources. The application simply computes something.

The strange thing is that also other apps do get affected by this web app.
So, the problem may be somewhere before asp.net even get chance to work
(maybe ISAPI dll, or IIS,.. ?)

Please help
Michal

 

[Mark Rae]

No. The pages do not use databases, nor do they use any other network
resources. The application simply computes something.

The strange thing is that also other apps do get affected by this web app.
So, the problem may be somewhere before asp.net even get chance to work
(maybe ISAPI dll, or IIS,.. ?)

Does the problem exhibit itself during debug in your development environment
or only in the live environment?

 

[Guest]

Does the problem exhibit itself during debug in your development environment
or only in the live environment?

It occurs in boths environments.
I've investigated the matter more thorougly, and I have found that the
problem is somehow related to network interface speed.
I created another, a very simple web form asp.net application, and did the
same thing: repeatedly press refresh button of web browser. Even with the
very simple application the problem occurs, however, the occurence of problem
depends of the network speed. If the network interface is fast (lopback) the
problem does not occur at all. If it is 100Mbit ethernet, it happens but very
rarely (and only if the application is complex). And if the network link is
something about 115 kbps (my WAN interface), it happens often (if pressing
continually refresh button at high frequency). And with this network adapter
the application can realy be simple - just several input fields and buttons.

The worst thing is the fact that not only this session freezes, but all
other users' sessions.
Also I noticed that the IIS web server is not affected by the problem in a
way that it still can handle requests (but to file types not handled by
aspnet ISAPI library). My application uses a frameset with two frames. The
frames link to aspx pages. And if the problem occurs, frames contents are not
returned (for some time) , however the html page definig the frameset can be
fetched (and displayed by the browser).

Any help will be appreciated
Thanks
Michał Januszczyk