asp.net web application request timeout

I have a problem with my asp.net web application. During the test process, there w开发者_运维百科as no problem but after a lot of users started to use application, it gets timeout.. Where should i check for this problem?

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Wow, that's... not a lot of detail. :/

You have a resource bottleneck somewhere. That could be a DB connection, the web-server itself, or the physical machine resources (i.e. memory). It could be some IDisposable object you aren't releasing, I've seen similar behaviour from an app full of statics which shouldn't have been - basically it could be anything.

You need to start applying diagnostic tools: Trace, a DB profiler like MS SQL Profiler if you have one, simple logging at IIS and application level, etc...