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I recently got a question about if it is possible to generate full user mode dumps automatically every time the process crashes (without having debug diag or adplus installed and monitoring your system). This would be useful for example if you are setting up a site, and you want to make sure you get dumps if it ever crashes so that you don’t have to repro the issue at that point, just to get data. It turns out that starting with Windows Server 2008 and Vista + SP1, Windows Error Reporting (WER) will let you do just that. It even worked on my Win 7 machine. http://msdn.microsoft.com/en-us/library/bb787181(VS.85).aspx The documentation here says that “Applications that do their own custom crash reporting, including .NET applications...

Is it a plane, is it a bird, is it a UFO? Before you can delve into any kind of troubleshooting of an issue you need to thoroughly define it.  If you don’t you’ll probably end up spending a lot of time randomly gathering and looking at data that is probably not even relevant to the issue at hand.  More importantly, how do you even know that your problem is fixed if you don’t have a good definition of the problem? This might sound like common sense, but having worked with troubleshooting the better part of the last 10 years I can tell you that it is extremely common that people start looking at data before really understanding the problem.  More often than not this is because people are stressed and want to fix the problem fast...

I came back from a long vacation today and I’ve finally caught up with enough emails to do something useful with my day. As I scanned through my blog email bucket I noticed that I had a lot of emails relating to my last post on dumping .net exceptions in windbg , and most of them asked why they see OutOfMemoryExceptions on the heap, and how to troubleshoot this. I think I have mentioned this before, but it seems like it is worth mentioning again as it is probably buried deep in some post from way back when… When you dump out all the exceptions on your .net GC heap (using !dumpheap -type Exception for example) these 3 types of exceptions will always show up, independently of what type of .net process you are debugging. 79330c30       ...

A few weeks back me and Micke (one of our Architect Evangelists) had a session at TechDays where we talked about “things that looked good on paper” i.e. things that sound pretty ok in the design/development phase but sometimes turn out to be a disaster in production. We are both pretty passionate about making the lives of the ops. people easier by thinking about the maintenance of the sites/apps at design time, rather than having it be an afterthought.  I stole the title of this post from one of Mickes talks about bridging the gap between dev and ops.  The topics we brought up are based on issues that we commonly see in prod. environments and we started off each section with a quote and dissected the pros and cons and what we think...

During mine and Micke’s presentation at TechDays this week I showed a demo of setting up rules with Debug Diag to identify the cause of a crash in an ASP.NET application. Even though debugging might be tricky, setting up rules in Debug Diag is beautifully simple and I personally believe that it would be a good idea for anyone running a web site to have debug diag installed along with a few instructions for the ops personnel on how to set up the rules.   Better yet,  you can set up the rules in advance and just activate or deactivate them as needed. Here is a recap of that demo… Problem description The application crashes with the following event in the eventlog Log Name:      Application Source:          ...

My TechEd presentation “Common Issues in ASP.NET and how to debug them with Windbg” is now up on channel 9, so if you want to watch it, here you go http://channel9.msdn.com/posts/MSDNSweden/Vanliga-fel-som-grs-med-ASPNET-och-hur-du-hittar-dem-med-WinDbg/ Have fun, Tess Read More...

... and here are the slides for the interactive session Read More...

I still have to figure out a way to host the video from the break-out session but until then, here are the slides for my presentations (attached). And here are a list of some of the tools and resources I used for the presentations Tool/Resource Comment Download Link Debugging Tools for windows Windbg, adplus etc. http://www.microsoft.com/whdc/devtools/debugging/default.mspx Debug Diag 1.1 Analyzes dumps, good for native memory leaks http://www.microsoft.com/DOWNLOADS/details.aspx?FamilyID=28bd5941-c458-46f1-b24d-f60151d875a3&displaylang=en Cmdtree Command and textfile to get a treeview with commands in windbg http://www.wintellect.com/CS/blogs/jrobbins/archive/2008/09/17/windbg-cmdtree-file-that-eases-some-sos-pain.aspx Tinyget Poor mans...

Here are of some of the reader emails I got this week and my answers to them... How do I troubleshoot this memory leak Debugging techniques for capturing stacks of OOMS Do you have a list of Debugging 101 links? Debugging managed code in IE Getting to dependency properties with sos let me know if this is something you find useful so I should keep doing it from time to time, or if it's only useful for the selected few who's email I happened to pick this week:) Note: some of the emails have been edited to fit better in a Q/A format, hopefully I haven't missed any important bits... Q: How do I troubleshoot this memory leak I started observing a slow leak in task manager of about 100 MB / 30 mins, in a web application consisting of WCF...

I have probably mentioned this before, but I think it is worth mentioning again because of the frequency of this issue. When debugging a crash, we usually get customers to use a crash rule in debug diag or to use adplus -crash to get memory dumps at the point of the crash.  Both of these attach to the process and gathers dumps when the process is shutting down, which is exactly what we want... The problem is that very often we will get what I call "false-positive" dumps.  I.e. dumps when the process is shutting down, but not dumps of an actual crash, or at least not the shutdown we are trying to troubleshoot. A typical characteristic of such a memory dump is that thread 0 is in the middle of a "normal shutdown"...