asp.net web config |

CheapASPNETHostingReview.com | Best and cheap ASP.NET Hosting. Some times after hosting web application on the server, we get unexpected error as shown in the below fig. But we did get the detailed message for the unexpected errror. In this article, I would like to share how can we get detailed message for the unexpected error.

This type of unexpected error may occurs on local or remote server. In asp.net, we can find the exact error message by setting mode=”Off” with in customErrors tag in web.config of our application. This is the way by which we can find out the exact error in our web application

 &lt;system.web&gt; 
&lt;customErrors mode="Off"&gt;
 &lt;/customErrors&gt; 
 ...
 ...
 &lt;/system.web&gt;

<system.web>

</customErrors>

...

</system.web>

When we set the customErrors mode=”Off” then we can easily track the error in the application as shown in the fig.

In Asp.net, there are three error modes to trace an error. These modes decide whether or not an error message is displayed. RemoteOnly mode is default mode for displaying error messages.

Off Mode
This mode is responsible for displaying error mesage on local and remote server in case of an error.
On Mode
This mode is responsible for displaying custom error page with message on local and remote server in case of an error. By using this mode, we can show our own custom error messages page for specific errors on local and remote server.
RemoteOnly
This mode is responsible for displaying error mesage on remote server only in case of an error. By using this mode, we can show our own custom error messages page for specific errors on remote server only.

I hope you will enjoy these tricks while programming with Asp.Net. I would like to have feedback from my blog readers. Your valuable feedback, question, or comments about this article are always welcome.

CheapASPNETHostingReview.com | Best and cheap ASSP.NET Hosting. The ASP.NET framework provides built-in settings to control how to respond when an application error occurs. This functionality is part of the Web.Config customErrors section.

Configuration Options for Web.Config <customErrors>

Like most web.config settings, customErrors can be configured within the Machine.config, root web.config or your application web.config file. Usually, it is set per application.

CustomErrors supports the following modes:

On – If defaultRedirect is specified, they will see that content. Otherwise the default error screen with fewer details.
Off – Detailed error details will be shown to the user. (the “yellow screen of death screen”)
RemoteOnly – Default value. Detailed errors only are shown to local users. Remote users receive custom error screens or fewer details.

Example configuration:

<configuration>
  <system.web>
    <customErrors defaultRedirect="YourErrorPage.aspx"
                  mode="RemoteOnly">
      <error statusCode="500"
             redirect="InternalErrorPage.aspx"/>
    </customErrors>
  </system.web>
</configuration>

<system.web>

<customErrors defaultRedirect="YourErrorPage.aspx"

mode="RemoteOnly">

<error statusCode="500"

redirect="InternalErrorPage.aspx"/>

</customErrors>

</system.web>

</configuration>

How to View Full ASP.NET Error Details, Disabling Custom Errors

If your application is throwing errors, but you cannot see the full error message, you can disable customErrors.

To do this, you will want to set customErrors mode to “Off” as shown below. Be careful though as this could expose sensitive information shown in error messages as well as detailed stack traces.

<configuration>
  <system.web>
    <customErrors mode="Off"/>
  </system.web>
</configuration>

<system.web>

</system.web>

</configuration>

Other Ways to View ASP.NET Exceptions

There are other ways to track, find, and view application errors besides the ASP.NET yellow screen of death. Ideally, your application should be logging all of your errors to a log file and error monitoring service. You can also check Windows Event Viewer, and you may be able to see your exceptions. Although, be warned that exceptions are rate limited to Event Viewer and it does not record all of them.

How to Log All Application Errors

Depending on your type of application, there are potentially multiple ways to do this. If your application has a Global.asax file, you can subscribe to unhandled exceptions as shown below:

public class WebApiApplication : System.Web.HttpApplication
{
	log4net.ILog log = log4net.LogManager.GetLogger(typeof(WebApiApplication));

	public override void Init()
	{
		base.Init();
		this.Error += WebApiApplication_Error;  
	}

	void WebApiApplication_Error(object sender, EventArgs e)
	{
		var ex = Server.GetLastError();		
		log.Error(ex);            
	}
}

public class WebApiApplication : System.Web.HttpApplication

{

log4net.ILog log = log4net.LogManager.GetLogger(typeof(WebApiApplication));

public override void Init()

{

base.Init();

this.Error += WebApiApplication_Error;

}

void WebApiApplication_Error(object sender, EventArgs e)

{

var ex = Server.GetLastError();

log.Error(ex);

}

How to View All Application Exceptions With Retrace

Retrace provides code-level performance monitoring for your application. Part of that includes collecting all application exceptions. Retrace can collect unhandled exceptions, exceptions explicitly logged to it, or every single exception ever is thrown (first chance exceptions).

To make the most of your application errors, you should use an error monitoring service, like Retrace. Benefits of an error monitoring service:

Real-time alerts – know immediately when a new error happens
Centralized repository – one place your team can access everything
Error rates – quickly identify large spikes in error rates
Improve productivity – find root cause of problems much faster

asp.net web config

How to Turn off Asp.net Custom Errors in Web.config

Off Mode

On Mode

RemoteOnly

Using Web.Config customErrors for ASP.NET

Configuration Options for Web.Config <customErrors>

How to View Full ASP.NET Error Details, Disabling Custom Errors

Other Ways to View ASP.NET Exceptions

How to Log All Application Errors

How to View All Application Exceptions With Retrace