Thoughts about IIS (and now SharePoint!) : .NET

Uncovering True Errors in SharePoint (and other .NET web applications)

jamesbl — Wed, 10 Jun 2009 00:30:29 GMT

Have you ever come across an error like this?

Or perhaps one similar to this?

Unfortunately, these types of “unexpected error” messages do not provide any level of detail as to the actual problem, but instead, only inform you, the admin, there was some type of error that prevented the expected page from coming up properly.

When this happens, there are two changes I make in the application’s web.config file, which have always helped uncover the true problem.

To show the call stack:

Change

<SafeMode MaxControls="200" CallStack="false"
DirectFileDependencies="10" TotalFileDependencies="50"
AllowPageLevelTrace="false">

to

<SafeMode MaxControls="200" CallStack="true"
DirectFileDependencies="10" TotalFileDependencies="50"
AllowPageLevelTrace="false">

To turn custom errors off, so the error and the call stack can be shown:

Change

<customErrors mode="On" />

to

<customErrors mode="Off" />

I’ve seen others mentioning the need to change AllowPageLevelTrace="false" to AllowPageLevelTrace="true", however, I have not had to do this with SharePoint thus far.

One you’ve saved your web.config, the appdomain will be torn down and reloaded on the next incoming request (this happens automatically upon any change to the web.config, by design) and you should be ready to find out your true error.

So, your IIS Manager comes up blank, too?

jamesbl — Fri, 29 Feb 2008 00:33:51 GMT

Have you ever opened the IIS Manager MMC (quick shortcut - Start/Run/inetmgr) only to find it comes up completely blank? Also, keen eyes will notice it takes a lot longer for the MMC window itself to appear as well, when this problem occurs. This phenomena appears to only occur if you have MOSS installed.

In any case, if you have seen this problem on one or more servers in your farm, you can work around it by simply restarting the OWSTimer service ("Windows SharePoint Services Timer" service). This is fairly acceptable to most since it does not require you to reset IIS or reboot the server (i.e. no downtime).

The good news is there is now a hotfix that should resolve this issue! Give Microsoft Support a call if you're experiencing this issue.

Determining if a .NET Assembly is compiled debug or not

jamesbl — Thu, 15 Jun 2006 00:30:00 GMT

Often times, in debugging various ASP.NET memory related issues, I find numerous assemblies that have been compiled in debug mode. One of the main problems, however, is the person I'm working with is almost always the one responsible for getting the server back up and running, and not the developer that created the debug assembly that's actually deployed to the server in question.

So I whipped up a little console application that returns the details on an assembly that gets passed on the command line.

using System;

using System.Reflection;

using System.Diagnostics;

namespace IsModDebug

{

public class IsDbg

// Errorlevels, for batch reasons:

// 0 = Non-Debug Assembly

// 1 = Debug Assembly

// 2 = No assembly name passed on command line

// 4 = Exception thrown

{

public static int Main(String[] args)

{

if (args.Length != 1)

{

Console.WriteLine("\nError: Not enough command line options specified.");

Console.WriteLine("Usage: \"IsModDebug <path to assembly>\"");

return (2);

}

try

{

Assembly asm = Assembly.LoadFile(args[0], null);

DebuggableAttribute objDebuggable =

(DebuggableAttribute)DebuggableAttribute.GetCustomAttribute(asm, typeof(DebuggableAttribute));

if (objDebuggable == null)

{

Console.WriteLine("Non-Debug Assembly");

return (0);

}

if (objDebuggable.IsJITOptimizerDisabled || objDebuggable.IsJITTrackingEnabled)

{

Console.WriteLine("Debug Assembly");

Console.WriteLine("JITOptimizerDisabled = {0}", objDebuggable.IsJITOptimizerDisabled);

Console.WriteLine("IsJITTrackingEnabled = {0}", objDebuggable.IsJITTrackingEnabled);

}

catch (Exception e)

{

Console.WriteLine("Exception: {0}!!!", e.Message);

return (4);

}

return (1); // Debug Module Found

}

Output looks something like this, when run against various assemblies compiled in various ways:

C:\>ismoddebug d:\rel.exe
Non-Debug Assembly

C:\>ismoddebug d:\deb.exe
Debug Assembly
JITOptimizerDisabled = True
IsJITTrackingEnabled = True

C:\>ismoddebug d:\deb2.exe
Debug Assembly
JITOptimizerDisabled = False
IsJITTrackingEnabled = True

Have Fun,