HTTP Error 500 Internal server error on high load ASP.NET application

I get HTTP Error 500 Internal server error on a one simple page asp.net application.开发者_运维知识库 There are enough resources on the server. This page is frequently requested by a large number of clients.

Is there any IIS related settings I have missed ?

The first stop here would be to enable Failed Request Tracing:

Troubleshooting Failed Requests Using Tracing in IIS 7
Troubleshoot with Failed Request Tracing

If doesn't produce anything that narrows things down then have a trawl through the System and Application Event logs.

Finally if it's still not obvious what's failing then it's time to dig out some toys from Tess Ferrandez's debugging toolbox:

.NET Debugging Demos - Information and setup instructions

.NET Debugging Demos Lab 2: Crash

.NET Debugging Demos Lab 5: Crash

.NET Debugging - Crash Scenarios

You need to dig down to determine the specific cause of the 500 error, be it a transient script error, resource error or a problem related to IIS's configuration.
Setup Failed Request Tracing, wait for an error and examine the log output.

1.Close your development environment (e.g., Visual Studio .NET).
2.Open a Command Prompt, and type the following commands:
3. iisreset /stop
4.net user ASPNET /delete [ u can ignore this step if this fails]
5. aspnet_regiis -i
6. iisreset /start
7.Close the Command Prompt.
8.Restart your development environment.