If you live in Sweden and haven’t signed up for TechDays 2009 yet, go ahead and check it out.  There are a lot of good speakers scheduled for the conference. What is even more exciting is that my support buddies will have their own track running in parallel with the main tracks where there will be a number of sessions about troubleshooting and troubleshooting related topics. I will be running a presentation (with Mikael Deurell ) about my favourite topic: debugging .net applications, what else...

In my last post I wrote about a WCF hang I caused because of a newbie mistake. I also wrote that I would post about how to create a simple WCF service. This tutorial is mostly for myself so that I’ll remember what I did, but hopefully it might benefit some other people too… The WCF service I will create here (MyGameService) is one that will keep track of all the games for my game site. Creating a WCF Service and hosting it in IIS 1. In Visual Studio 2008, choose File / New / Web Site… /...

I know it is a little late, but Happy New Year to all of you. My holiday break was great, and I wish I would have had some more time to blog, but instead I got an XBOX 360 and a Guitar Hero World Tour game so the blog had to take the back seat for a while… My whole family and even my mom are now hooked on GH so the evenings at my house have turned into family jam sessions:) Apart from playing GH and hanging out with family and friends, I spent most of my break writing Silverlight apps and games...

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

This is way out of the scope of what I normally troubleshoot, but I have gotten some questions around this and I just wanted to point out a really good resource (By Raffaele Limosani), for troubleshooting memory leaks in these kind of applications. http://blogs.msdn.com/raffael/archive/2008/02/21/netcf-memory-leak-now-what.aspx

There’s been close to 25 000 downloads of the buggy bits lab set , YAY!!! :)  but now I think it’s time to expand it a bit with some new labs.  I have a few different issues in mind but I wanted to check in and see if there is something specific you want to see in the new lab set.  I know that the first request I’ll probably get is to include something about COM debugging or debugging RCW/CCW leaks and I might do that, but I just want to say that I am struggling a bit with this. ...

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

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...

I'm back from TechEd in Barcelona, and it was one of the most fun, scary and humbling roller coaster rides I have ever been on. I am a bit of a glutton for punishment becuase I signed up to do two sessions and before I knew it I was scheduled to do one in the auditorium (on the largest stage I have ever seen, 760 sq ft). Not only that, but when I got to Barcelona they had scheduled me to do a repeat of the interactive session. I really do appreciate all the people that showed up at my sessions...

You learn something new every day… I was working on an issue with appdomain restarts caused by page re-compilations because aspx pages were created and modified from the code. You can get lifetime event information such as shutdown reasons, compilation information etc. in the eventlog by enabling Application Life Time Events in your web.config (See this post for more info about this and application restarts in general) We were seeing a lot of the following messages EventID: 1305 Event...

Mike Stall just wrote a very interesting post about ICoreDebug announcements at the PDC.  More specifically that ICoreDbg for 4.0 will support dump debugging which means that ICoreDebug based debuggers (eg. Visual Studio) will also be able to support this.  This is the best news I’ve heard in a long long time:) since it means that we can do post-mortem debugging in a bit more familiar environment than windbg (which is currently the tool of choice for this). Unfortunately I wasn’t at the...

Rico Mariani (Chief Architect of Visual Studio – previously performance architect for .net), Vance Morrison (Performance architect for .net) and Mark Friedman (Architect Lead for the Developer Division of Performance Engineering) had a full day talk at the PDC about performance. Unfortunately recordings are probably not going to be available since this was done at the pre-conference, but Vance posted all the slides they used on his blog . Performance by Design Intro – Rico Mariani Performance by...

TechEd EMEA Developers is just around 2 weeks away now and the pre-conference nervousness is starting to get to me:)   This will be my first time at TechEd (even as an attendee) so I am really excited. I was just chatting a little with one of the track-owners to figure out what the venue and the presentation rooms looked like to get a feel for what the sessions are going to be like.  They scheduled my breakout session ( WUX405 Common ASP.NET production issues and how to troubleshoot...

I am doing some email cleanup and got a request to write a post about how to use the HTTPERR logs. I thought long and hard about what I could write that would add value.  There is a really good KB article on the topic http://support.microsoft.com/default.aspx?scid=kb;en-us;820729 that goes through how to set it up properly and what all the error codes mean, and there is another good article from asp alliance on how to use LogParser to perform queries against the http error logs to sift through...

Back in August I wrote a post about how to debug these types of issues in silverlight applications.  Since Silverlight 2.0 RTM’d this is now a bit more relevant so just wanted to refresh your memory that you can debug these types of applications and issues with windbg and sos if neccessary. http://blogs.msdn.com/tess/archive/2008/08/21/debugging-silverlight-applications-with-windbg-and-sos-dll.aspx The version numbers are different now but all the rest is the same. Tess

I hope you will join me for TechEd in Barcelona on the 10th-14th of November. I will be presenting 2 sessions, one breakout and one interactive session: WUX405 Common ASP.NET production issues and how to troubleshoot them with windbg “ This session presents the most common causes for hangs, performance issues, crashes, and memory problems in ASP.NET applications. The problems and demos shown are a compilation of many years of experience in troubleshooting these types of issues for some of our largest...

Following my post about how to troubleshoot a low CPU performance issue with VSTS Test, I will now do the same for lab 4 where we have high CPU in GC. The scenario is pretty similar in that we have a page ( http://localhost/BuggyBits/AllProducts.aspx ) that seems to be taking a lot of time to execute. We also see that the w3wp.exe process sits at very high CPU ~100% during the time this page executes. Using Windbg in the lab, we saw that the issue here was that we were concatenating a very...

I’ve been wanting to dig into the Test features in Visual Studio Team System for a while to “debug” issues during the test phase. In my previous post I linked to a Swedish screen cast by Mikael Deurell, but for those of you who don’t know Swedish I thought I’d walk through troubleshooting a couple of my labs using the Visual Studio Team System Profiler and Load Tests. Problem description The issue we will troubleshoot comes from lab 1 in my BuggyBits lab set, and the scenario here is that we...

I know that perhaps not that many of you know Swedish, but for those of you who do, you might want to check out Michael Deurell’s nice screen casts about how to use visual studio test system to troubleshoot the issues in the buggybits labs along with some windbg fun…  His screen casts are called “Fräschast i Bandhagen”, just love that name (unfortunately doesn’t translate that well to English:)) http://blogs.msdn.com/deurell/archive/2008/09/30/debugga-i-produktion-eller-testa-bort-i-utveckligsfas...

John Robbins beat me to the punch and wrote an excellent post about using .cmdtree in windbg to ease some .net debugging pain in windbg. The windbg .cmdtree command allows you to create a popup window in windbg with commands that execute when you click on the respective link...  so you no longer have to remember all the sos commands to get around in your managed dump. Read his post here and with the command tree text file he provides you will be up and running in no time...  You can also...

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...

I was helping a colleague out with an OOM (OutOfMemory) situation he was dealing with. Problem description: Their applications memory usage would grow over time until they finally ended up with an out of memory exception. First debug: They had gotten a memory dump when memory usage was really high 1.4 GB using debug diag and I opened it up in windbg.exe , loaded up sos (.loadby sos mscorwks) and ran !dumpheap -stat to get the content of the GC heaps. 0:028> !dumpheap -stat Statistics...

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...

From time to time we get issues with high memory and performance issues due to massive viewstate. I have talked about it before here , but I thought I'd show some techniques for finding out which pages have high viewstate. If you look at a memroy dump of your process in windbg and notice that your large object heap is riddled with viewstate strings, that doesn't really tell you much, except for that you have some pages that have high viewstate, so the goose chase begings trying to find the source...

When you have to pass an object back and forth between processes or application domains you have to serialize it into some type of stream that can be understood by both the client and the server.   The more complex and big the object gets the more expensive it is to serialize, both CPU wise and memory wise, and if the object is big and complex enough you can easily run into out of memory exceptions during the actual serialization process... and that is exactly what happened to one of my...