Naming tests
I’m a sucker for clean, minimalistic code, that is easy to read, understand and maintain.
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Organizing ASP.NET Core Minimal APIs
I often hear (on social media or direct comments) people saying you can’t use minimal APIs for “real production” apps.
Entering geek territory or exiting geek territory? That’s the question…
After 12 years in support I decided to lift my head above the WinDbg window and take a look at what the rest of the world has to offer.
Reader email: Need help troubleshooting perf/memory issues
I get several emails every day (through the blog) with urgent requests to help troubleshoot memory issues or memory related performance issues. Some just say...
Fix for RestartWWWService=false in Visual Studio 2010
We recently published a fix for the following problem:
Debug Diag 1.2 (Beta)
Are you looking for some good stuff to put in your family’s Christmas stockings this year? Maybe a new phone, a controller for your gaming console, why not a...
Capturing memory dumps for 32-bit processes on an x64 machine
This is an issue that I often get questions around and we often have cases where we have to re-capture memory dumps because the memory dumps were captured th...
Help! !clrstack is not showing any method names
From time to time I get questions about missing method names in the sos !clrstack output, like this
Getting full user mode dumps automatically when your process crashes
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...
.NET Memory Leak: XslCompiledTransform and leaked dynamic assemblies
I have written before about high memory usage caused by improper usage of XmlSerializer objects both in a case study and in a debugging lab. The problem ther...
New Visual Studio 2010 and .NET 4 debugging content
It’s been a pretty busy few weeks at work coupled with some vacation so I’ve been lagging a bit with the blogging, so sorry for bombarding the blog with new ...
Debugging a classic ReaderWriterLock deadlock with SOSex.dll
I was helping out on an issue the other day where the process would stall if they added enough users in their load tests. BTW, serious kudos to them for maki...
IIS and PAE
I recently got a question by one of my customers about PAE and IIS that I thought I’d share the answer to.
New debugger extension for .NET (PSSCOR2)
Tom just blogged about a new debugger extension called PSSCor2, which is a superset to the SOS.dll extension that ships with the .net framework.
Videos of developer sessions at Oredev (including mine on .net debugging)
Just a quick post to share a link to last years videos for the Oredev developer conference
Tool for generating DGML graphs showing why your object can’t be collected (VisualGCRoot)
Visual Studio.NET 2010 has a new feature that allows you to create nice directed graphs with a markup language called DGML (Directed Graph Markup Language).
New commands in SOS for .NET 4.0 Part 1
My friend and fellow debugger Brian at http://Kodehoved.dk recently wrote a couple of posts on news with sos for .NET framework 4.0 (in Danish)
System.Configuration.ConfigurationErrorsException Unrecognized element ‘setting’ and other unrecognized elements
If you have a .NET configuration file with multiple <setting> elements, you may get the following exception:
Debugging Native memory leaks with Debug Diag 1.1
I often get questions about debugging native memory leaks. In other words, cases where you have high memory usage in your application but you can see that .n...
High CPU in .NET app using a static Generic.Dictionary
A couple of weeks ago I helped out on a high CPU issue in an ASP.NET application.
More debugging videos and a Resource List from my TechED and Oredev sessions on debugging asp.net applications
I just returned from Oredev and TechED EMEA, both conferences were very interesting in their own special ways.
Recap of Oredev and some .net debugging videos
This week I attended and spoke at the Oredev conference in Malmö Sweden, and it was great fun as usual. It was a pretty productive few days with a lot of goo...
WOHOO!!!, Debug Diag 64bit is finally released
For all of you who have been asking me if there is a 64bit version of Debug Diag (used to debug 64 bit processes), I am happy to say that yes, Debug Diag 1.1...
.NET Hang Case study: The danger of locking on strings
I had an interesting case today where an asp.net app got stuck in a true deadlock. In other words two threads were both waiting for resources that the other ...
Debug Diag: mscorwks.dll is responsible for 372.46 MBytes worth of outstanding allocations
I got an email today on an issue that I think is pretty common when you try to memory leak analysis on a dump with debug diag.
ASP.NET Case Study: Hang when loading assemblies
The other day I came across an issue where an ASP.NET site stopped responding and didn’t start serving requests again until the W3WP.exe process was restarte...
Forms authentication fails after installing IIS 7.5
I recently had a customer that just moved from Windows 2008 to Windows 2008 R2 (changing from IIS 7 to IIS 7.5) and after the move they got some weird forms ...
First step in troubleshooting complex issues: Define and scope your issue properly
Is it a plane, is it a bird, is it a UFO?
How can I make you learn and benefit from my Blog? and how can I learn from you?
Summer is almost over and a new season of heavy work is beginning. I wanted to take this opportunity to start on a new page and make sure that I’m spending ...
Why do I see ExecutionEngineException, StackOverflowException and OutOfMemoryException on the heap when debugging .net applications?
I came back from a long vacation today and I’ve finally caught up with enough emails to do something useful with my day.
Design tips for Developers
I found a set of really nice, short videos by Arturo Toledo on the Silverlight blog that I thought were worth sharing.
A case of lost session variables when using out of process session state
Recently I had a case where the customer had an issue with session variables. The claim was that if they use in-proc session state their session variables w...
First look at debugging .NET 4.0 dumps in Visual Studio 2010
I know that for a lot of you this is a bit far into the future, but I thought it would be nice to run through a few of my lab scenarios to show off some of t...
Background Garbage Collection in CLR 4.0
Yesterday I found this really nice Channel 9 interview with Maoni Stephens (Dev Owner of the CLR GC) and Andrew Pardoe (Program manager for the CLR GC) where...
Debug Diag script for troubleshooting .NET 2.0 Memory leaks
I have put together a quick and dirty debug diag script for troubleshooting .net memory leaks.
Neat .NET 2.0 StackViewer to troubleshoot hangs/performance issues
Bret wrote a post about Managed Stack Explorer, a really nice tool that was developed in 2006 but since then seems to have been forgotten.
Unable to load DLL ‘dllname.dll’: A dynamic link library (DLL) initialization routine failed. 0x8007045A
I recently got an email with the following question:
Show me the memory: Tool for visualizing virtual memory usage and GC heap usage.
A colleague of mine, John Allen, created an awesome tool way back that displays memory usage in a process very nicely. I use screenshots from it from time to...
.NET Exceptions: Quick WinDbg/SOS tip on how to dump all the .NET exceptions on the heap
Since a .net exception is a .NET object like any other, it gets stored on the GC heap when you (or some code you call) calls new XXException().
Validation of viewstate MAC failed after installing .NET 3.5 SP1
After installing .NET 3.5 SP1 you may get Validation of viewstate MAC failed exceptions when doing post backs on ASP.NET pages
Developers are from Mars, Ops people are from Venus… or It looked good on paper
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. thin...
Debugging a .NET crash with rules in Debug Diag
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...
Silverlight/WPF FlipImage Animation
I was working on some Silverlight samples and needed an image that could flip over.
.NET Rocks: Debugging chat
Yesterday I had a nice chat with Richard and Carl at .NET Rocks. We talked about .net, debugging, memory issues and a bunch of other stuff, and in the end I ...
Silverlight 2.0 Walkthrough – Creating a “Traffic Jam” game (now in WPF)
This lab series is not really in-line with my normal debugging posts, but I just created a simple Traffic Jam game in Silverlight and thought I’d make it int...
.NET Memory Leak reader email: Are you really “leaking” .net memory
I get several emails every week through the blog asking for help on various issues. Unfortunately due to time constraints I can’t really look at them all on...
.NET Memory Leak: To dispose or not to dispose, that’s the 1 GB question
I was looking at a memory dump recently for an issue where the process would grow to over 1 GB and return OutOfMemory Exceptions.
.NET Hang: Analyzing Debug Diag output
Earlier this week I got an email from a reader who had a hang in an application and sent in some Debug Diag logs.
TechDays Sweden March 17th-18th 2009
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.
WCF 101 – Creating and consuming a basic WCF Service hosted in IIS
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 ...
.NET Hang: My application hangs after I called my WCF service a couple of times
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 g...
Video of my TechEd presentation of Common Issues in ASP.NET and how to debug them with Windbg
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
Planning a new .net debugging lab set – What do you want to see?
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.
Slides for interactive TechEd Sessions about debugging .net issues in windbg
… and here are the slides for the interactive session
Slides and resources for TechED presentations about debugging .NET issues with Windbg
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.
Behind the scenes at TechEd EMEA - Things I learned about presenting at large conferences
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.
Troubleshooting app domain restarts and other issues with ETW tracing
You learn something new every day…
PDC announcements about Dump debugging for .NET 4.0
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 ...
Performance by Design – PDC 2008
Rico Mariani (Chief Architect of Visual Studio – previously performance architect for .net), Vance Morrison (Performance architect for .net) and Mark Friedma...
Need your input for TechEd EMEA sessions on troubleshooting .net applications
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 (e...
.NET Debugging at TechED EMEA (10-14 November in Barcelona)
I hope you will join me for TechEd in Barcelona on the 10th-14th of November.
Using VSTS Test and Profilers to troubleshoot a High CPU in GC issue
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.
Using VSTS Test and Profilers to troubleshoot performance issues (low cpu hang)
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 linke...
Making it easier to debug .net dumps in windbg using .cmdtree
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.
Q&A Reader emails about .NET memory leaks and random questions
Here are of some of the reader emails I got this week and my answers to them…
ASP.NET Memory Issues - High Memory Usage with AjaxPro (fixed in current version)
I was helping a colleague out with an OOM (OutOfMemory) situation he was dealing with.
Quick Debugging Tip: Disable apppool recycling while getting crash dumps
I have probably mentioned this before, but I think it is worth mentioning again because of the frequency of this issue.
ASP.NET Memory - Identifying pages with high Viewstate
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 ...
OutOfMemoryExceptions while remoting very large datasets
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 underst...
Creating a UI Module For IIS7 to watch Current Requests
A while back I posted about Failed Request Tracing in IIS 7 and I mentioned the command appcmd list requests which lists the requests that are currently exec...
Debugging Puzzler - WinForms crash - Can you figure out what caused it?
Earlier this week I was doing a presentation and since the company I presented for had mostly win forms developers I wanted to convert all my ASP.NET debuggi...
Debugging Silverlight applications with windbg and sos.dll
If you have hangs, performance, memory issues, exceptions or crashes in Silverlight applications you can debug them using windbg and sos just like you would ...
Questions on application domains, application pools and unhandled exceptions
I got an email with some questions around application domains, application pools and unhandled exceptions from a developer that was frequently seeing his web...
Troubleshooting a performance issue with Failed Request Tracing and appcmd in IIS7
I know I’m a little late in the game, but I decided that after vacation it was finally time for me to install Windows 2008 on my Vista box and play around wi...
ASP.NET Memory Leak: Byte arrays rooted in System.Security.Policy.Evidence
Today I got a question from a reader (Chris) about a memory leak they are seeing in their application
Bag of Chips: Installing XNA Games on your Zune
It is not often that I stray too far from debugging and ASP.NET on my blog, but this time I am going to make an exception because I am just really excited ab...
100% CPU in vbc.exe when compiling large vb.net web applications in Microsoft Visual Studio 2008
We just released a hotfix for an issue where you get 100% CPU in vbc.exe when compiling large applications in Microsoft Visual Studio 2008.
Presenting at TechEd Developers Europe 2008, Barcelona
Save the date! TechEd Developers North America 2008 just finished but there is plenty more to come… I know it’s a bit early still, but November 10th through ...
ASP.NET Case Study: Deadlock waiting in GetToSTA
This is an issue I come across once in a while and since I am not a COM expert by any means I actually had to check in with our COM guys to see what was goin...
CLR Inside Out: Large Object Heap Uncovered
In many of my posts I have discussed performance issues and memory issues caused by excessive use of the Large Object Heap, here are a few examples.
Setting .NET breakpoints in Windbg for applications that crash on startup
I recently received a question from a reader who wanted to know how to set breakpoints in code for applications that crash on startup.
ASP.NET Memory: Thou shalt not store UI objects in cache or session scope
ASP.NET Memory: Thou shalt not store UI objects in cache or session scope Surprisingly the issue I wrote about in the event handlers that made the memory bal...
DebugDiag 1.1 or Windbg, which one should I use? and how do I gather memory dumps
If you have read any of my posts you have probably noticed that I am very partial to windbg and the debugging tools for windows. I often get friendly nudges ...
The 21 most popular blog posts
I started this blog 2.5 years ago today, mostly because I felt that the same types of issues came up over and over and over in our support cases. I figured t...
ASP.NET Performance issue: Large number of application restarts due to virus scanning
Issues caused by frequent application restarts are pretty common. If you are interested in what causes application restarts in general, and how you can monit...
Failed to start stack walk: 80004005, Following frames may be wrong and other errors you may see in windbg
When you debug .net applications you will sometimes get error messages in windbg. Here are a few of the ones I most commonly get questions around…
ASP.NET Hang: Authenticode signed assemblies
When you use authenticode signed assemblies in an application, the application needs to go out and check the certificate revocation lists (CRLs) to verify th...
Blog Interesting - 32 Ways to Keep Your Blog from Sucking
Today I came across a really good article for bloggers, Scott Hanselmans post on Blog Interesting - 32 Ways to Keep Your Blog from Sucking
ntdll!kifastSystemcallret, SharedUserData!SystemCallStub and search engines…
If I were to pick out ten keywords for my blog I would pick, in no particular order, ASP.net, windbg, sos, debugging, .net exceptions, memory leaks, performa...
ASP.NET Crash: StackOverflowException with Server.Transfer
I have written a few posts about StackOverflowExceptions, here, here, here and here. The one I am going to talk about today is one of those unfortunate cases...
Why are some commands missing in sos for 2.0 compared to sos for 1.1?
This question that I got from a reader is something that I get asked pretty frequently
Setting breakpoints in .net code using !bpmd
From time to time I get questions like our process spawns a lot of threads, how do we know who created them? or can I tell how many times we call this method...
Does interrupting GC.WaitForPendingFinalizers interrupt finalization?
I got a question the other day around calling GC.Collect and GC.WaitForPendingFinalizers.
Pimp up your debugger: Creating a custom workspace for windbg debugging
From time to time I get questions about how to change settings in windbg like this one…
How does the GC work and what are the sizes of the different generations?
During our ASP.NET debugging chat there were many questions around the GC and the different generations. In this post I will try to explain the basics of how...
My presentation on Troubleshooting ASP.NET production issues at Developer Summit 2008
The purpose of my presentation was to show some common pitfalls and of course to show off windbg and sos just to show people that if you have a hang, perf is...
Developer Summit Sessions on Silverlight, MVC, FaceBook, and Work ethics amongst software developers
On Wednesday I presented a session on troubleshooting ASP.NET production issues at Developer Summit 2008 in Sweden. It offered a lot of good presentations as...
.NET Performance Issues: What if I suspect that my performance problem is in SQL Server Part II
Last week Graham was guest blogging on my blog about PSSDiag and how to gather data with PSS Diag. In this second installment he talks about how to read and ...
.NET Performance Issue: What if I suspect that my performance problem is in SQL server?
Very often when investigating ASP.NET or other .NET performance issues we find threads stuck waiting for SQL Server or some other database to respond.
Recap of yesterdays ASP.NET Debugging Blog Chat
I have to say that I was happily surprised, not only that so many people showed up and about the amount of questions that came up but also about the type of ...
.NET Debugging Demos Lab 7: Memory Leak - Walkthrough
We have reached the end of the .NET Debugging Labs series. And we are going to end it with a walkthrough of the last memory leak lab.
Live blog chat about asp.net and debugging with windbg and sos (10 am EST/4 pm CET)
Welcome to the first blog chat for ASP.NET Debugging. I hope you enjoy this and please let me know your comments on the experience. I am planning on posting ...
Questions about .net Exceptions
One of my readers emailed me the following question
New version of SilverLatte and Espresso Blend available for download
I am sure that you have all been awaiting this new version of SilverLatte and Espresso Blend as much as I have. Last week I got a chance to test out the new ...
.NET Case Study: Stackoverflow Exception when using a complex rowfilter
When you use very complex row filters or expressions on datasets or data tables you may end up getting a StackoverflowException.
ASP.NET Case Study: Hang with mixed-mode dlls
If you use mixed mode dlls (assemblies with .net and c++ code) you need to take care to not have any .net entry points so that you don’t end up with a GC/Loa...
.NET Debugging Demos Lab 7: Memory Leak
This is the last debugging lab in the .NET Debugging Labs series. By now you should have the basics down for troubleshooting hangs, perf issues, memory leaks...
.NET Debugging Demos Lab 6: Memory Leak - Walkthrough
Since it took me so long to get Lab 6 out the door i’ll post the review right away… After this we only have one memory leak lab to go before you have gone th...
.NET Debugging Demos Lab 6: Memory Leak
It’s been about a week since I posted the debugging challenge for this lab, things have been a bit busy lately so sorry about the tardiness on posting the l...
.NET Debugging Demos Lab 6: Debugging Challenge
Here is the debugging challenge for lab 6, this one is really tricky.
ASP.NET Case Study: Hang on WaitOne, WaitAny or WaitMultiple
One of the synchronization methods in .NET is the ResetEvent. It comes in two flavors, the AutoResetEvent which resets itself immediately after it is set, an...
.NET Debugging Demos Lab 5: Crash - Walkthrough
Since I already posted a challenge for this lab earlier, I didn’t want to wait too long with publishing the walkthrough
.NET Debugging Demos Lab 5: Crash
Last week I published a debugging challenge for Lab 5. It was really interesting to see the results and I have to say I was really happy to see the excellen...
Silverlight 2 Beta 1 and Expression Blend
ScottGu has outdone himself again with a demo series First Look at Silverlight 2 and First Look at using Expression Blend with Silverlight 2.
.NET Debugging Demos Lab 5: Debugging Challenge! (time to test your knowledge)
We’re about halfway through with the labs so to change it up a little bit I’m going to give you a debugging challenge.
Generational GC (Garbage Collector) - A post-it analogy
I was working through the High CPU Lab Walkthrough which is basically caused by high CPU in GC. To understand what happens you need to know what a generation...
.NET Debugging Demos Lab 4: High CPU hang - Walkthrough
Hope you have had a chance to go through the high CPU lab… Some people already commented with the solution in the lab instructions but here are my answers an...
Reader Email: Private Bytes remain higher than expected
I got this question today (through the blog) and normally I don’t really answer questions sent to me directly through the blog for a couple of reasons alread...
.NET Debugging Demos Lab 4: High CPU hang
So we finished the first round of performance issues, crashes and memory leaks.
I’m presenting at Developer Summit 2008 (in Sweden)
It’s that time of year again… on the 9th of April I will be presenting at ExpertZone Developer Summit 2008 in Sweden.
.NET Debugging Demos Lab 3: Memory - Walkthrough
This is the walkthrough of Lab 3 in the Buggy Bits series
High memory usage with usercontrols in IE (using Debug Diag)
I was helping a colleague with an interesting case yesterday concerning a memory leak in IE when using win forms user controls.
.NET Debugging Demos Lab 3: Memory
TGIF, almost time for the weekend, but before you leave, here is lab 3.
When a mommy and a daddy love each other…
It’s been a long time since I posted anything in the bag of chips category but man, this book really made me laugh :) Why read stories to your kids about Cin...
Hang caused by GC - XML Deadlock
In December I blogged about a little tool that I wrote to analyze hangs in dumps, and i showed the following output, but didn’t really get into the details o...
.NET Debugging Demos Lab 2: Crash
It was nice to see that so many people downloaded the demo site already and checked out the lab instructions for the first lab.
.NET Debugging Demos Lab 1: Hang- Walkthrough
Earlier this week I published the first .NET Debugging Lab. If you haven’t tried it out yet, here are the instructions.
.NET Debugging Demos Lab 1: Hang
This is the first in a series of about 10 labs on .NET debugging. The lab will use a site called BuggyBits, and as the name suggests the bits are extremely b...
.NET Debugging Labs - Information and setup instructions
.NET Debugging Labs
Learning .NET debugging
I often get questions like How do I learn .net debugging? What books should I read? Where can I find more information?
ASP.NET Hang and OutOfMemory exceptions caused by STA components
I have talked about blocked finalizers before and this issue is a special case of blocked finalizers where we are not really finalizing a .NET object but rat...
Using WinDbg - Advanced commands
Update 2021: This is a re-post of a post from Johan Straarup - I am posting it here as his blog has been decommissioned
ASP.NET hang/slowness on startup
After making some changes to their domains one of my customers noticed that their ASP.NET 2.0 applications didn’t respond anymore. HTML pages and images were...
Using Reflector to search through code and resolve .NET issues
As you already know, i spend my days analyzing dumps for customers, and more often than not I don’t have access to the customers code.
Case Study ASP.NET Deadlock calling WebServices
Lately, no matter where you turn there are linq presentations and Silverlight demos. A couple of years back the hot new stuff was web services and XML.
Automated .NET Hang Analysis
In my constant effort to make my job obsolete, I have created an “add-in” for windbg that automatically checks for hang conditions in a .NET memory dump.
Getting started with windbg - part II
Update 2021: This is a re-post of a post from Johan Straarup - I am posting it here as his blog has been decommissioned
Getting Started with Windbg
I’m back from Oredev which turned out to be a really cool conference.
ASP.NET Crash: System.Security.Cryptography.CryptographicException
This has been a busy month for blogging for me, I’m up to a whopping 8 posts this month including this one which is the most I have written in any given mont...
Why is my app performing worse on .NET 2.0 than on 1.1 (or why aren’t the oranges at work as tasty as the apples at home?)
If you were to compare the taste of the oranges in the fruit basket at work to the taste of the apples you bought on your way home and realize that they tast...
My Team is Hiring
Time for a commercial break,
ASP.NET 2.0 OutputCaching - Download dialog box after browsing with SmartPhone
A few days ago I got an interesting case with a customer who intermittently kept getting a download box with Safari and a similar one telling him that he has...
.NET Hang case study - High CPU because of poorly formatted regular expressions (Identifying tight loops)
Sometimes you hear and accept advice but you don’t really know the details behind it. That has always been the case with me and high CPU situations caused by...
.NET Finalizer Memory Leak: Debugging with sos.dll in Visual Studio
Normally I write about issues that only manifest themselves in production environment, issues that you can’t really reproduce in a controlled dev environment...
I’m presenting at Oredev in Malmo, Sweden Nov 13th-15th
Nov 13th-15th I will be presenting at Oredev in Malmö, Sweden. Oredev is a tech conference and this year it looks really promising considering all the big na...
Debugging Script: Dumping out ASP.NET Session Contents
In my last post I wrote a script to dump out all the ASP.NET requests on the heap. Since one of the most common memory issues I encounter is too much cache o...
Debugging Script: Dumping out current and recent ASP.NET Requests
When you debug asp.net applications it is often useful to find out which requests are currently executing, how long they have been executing, what the query ...
ASP.NET Hang scenario: Kernel Debugging for Dummies
Having debugging as a profession, you might have thought that I would have done a lot of kernel debugging, but since I deal mostly with ASP.NET and .NET deve...
ASP.NET Memory Investigation
This is a bit of a continuation of ASP.NET Memory Issue: High memory usage in a 64bit w3wp.exe process so if you haven’t checked it out you might want to jus...
ASP.NET Hang Case Study: Application hangs on startup
Recently we have been getting quite a few similar hangs in ASP.NET. From the first look they really aren’t all that similar but when we get down to the nitty...
ASP.NET Memory Issue: High memory usage in a 64bit w3wp.exe process
By default when you run IIS on a 64-bit machine you will still be running a 32-bit w3wp.exe, so apart from a few differences, like being able to use 4 GB vir...
A Case of Invalid ViewState
Last week I was helping a colleague of mine with a ViewState case that turned out to be pretty interesting…
Bag of Chips: What should I do with my butler?
This year the Swedish Microsoft Office won the “Best place to work” award from the Great Place to Work institute for the second year in a row.
WinDBG Scripts
I see post-mortem debugging as:
Swedish .NET Debugging PodCast
I know most of you probably don’t know Swedish, but for those of you who do, here is a link to a podcast where Dag König is interviewing me about .NET issues...
.NET Garbage Collection PopQuiz - Answers
It was really exciting to see that so many people answered the .NET GC PopQuiz, especially seeing that so many had great answers. Perhaps the questions were ...
.NET Garbage Collection PopQuiz
Time for a little pop-quiz/potential interview questions to get some action going in the comments section…
Things to ignore when debugging an ASP.NET Hang - Update for .NET 2.0
I often get questions like “what is this thread doing?”. A lot of the time it is about threads that are essential to the process but completely unrelated to ...
ASP.NET Case Study: Tracing your way to Out Of Memory Exceptions
One of my colleagues asked me to look at a memory dump for a customer and I thought that was I found was fairly interesting so here is the story.
High CPU in GC and other badness caused by SetProcessAffinityMask
I thought I’d share a support story with you from a very interesting case I have. My customer is running a pretty busy ASP.NET application on an 8-way box. A...
Developer Summit 2007
A short commercial break… I’ll be talking about debugging ASP.NET issues at Developer Summit 2007 in Stockholm on May 23rd.
.NET Hang Case Study: The GC-Loader Lock Deadlock (a story of mixed mode dlls)
I’m sorry I haven’t had a chance to write much lately because of a lot of different reasons. I moved houses and at the same time I started writing some manag...
I’ve been Tagged
I was Tagged by David Salgado so here are 5 things you probably don’t know about me…
Short note on some debugging related stuff…
December has been a very busy month, so I am sorry that I haven’t had time to write anything…
ASP.NET Crash: Bad CacheItemRemovedCallback - Part II
In August I wrote about how you could cause a nasty high memory situation by using CacheItemRemovedCallbacks improperly, today I got a case where improper us...
ASP.NET Case Study: Bad perf, high memory usage and high CPU in GC - Death By ViewState
I get enough issues relating to bad perf caused by large views tate that I felt like it is time to dedicate some blog space to it, so here is a typical probl...
.NET Hang Debugging Walkthrough
I have talked about a number of different hang/performance issues in my posts. This post is a generic debugging walk through for hangs. It applies to all t...
ASP.NET 2.0 - Investigating .NET Exceptions with WinDbg (Compilation and Load Exceptions)
I have talked in earlier posts about how to log and debug .net exceptions with WinDBG.
My Blog posts in Chinese
Courtesy of Ring some of my blog posts are now available in Chinese. Thank you much Ring for taking the time to translate…
ASP.NET Crash - Crazy looping in a SiteMap
It’s been a while again. Lots of prepping for the debugging workshops and a bit of re-modeling done to the house but now it’s time to write again…
Upcoming Premier .NET debugging workshops in northern Europe
I know this might be a select group, but if you have a Premier contract with Microsoft, and you live in northern Europe, and you are interested in learning ....
.NET Memory usage - A restaurant analogy
My favorite author Simon Singh is a wiz at analogies. In his book The big bang he explains concepts like the doppler effect and the theory of relativity usin...
ASP.NET Quiz Answers: Does Page.Cache leak memory?
A few days ago I posted a question I had gotten on email
ASP.NET Quiz - Does Page.Cache leak memory?
Yesterday I received an email from a blog reader about caching and memory leaks…
ASP.NET Case Study: Lost session variables and app domain recycles
Last night I got a question from one of the readers of the blog that went like this:
ASP.NET Case Study: High CPU in GC - Large objects and high allocation rates
Rather than spending a lot of time on explaining the details of the garbage collector, I’ll refer you to Maoni’s blog for some very interesting reading, but ...
.Net exceptions - Tracking down where in the code the exceptions occurred
I have written earlier about how to track down exceptions using configuration scripts for adplus.
ASP.NET 2.0 Crash case study: Unhandled exceptions
For a long time all my case studies have been on 1.1. it’s time to venture out in 2.0 land and look at what may seem like a 2.0 specific issue.
ASP.NET Memory - If your application is in production… then why is debug=true
Ensure that the debug="false" on the <compilation> element in the web.config file of each and every ASP.NET application on the server. The default d...
ASP.NET Strong named assemblies should not be stored in the bin directory
In ASP.NET 1.1, do not deploy strong named assemblies to the BIN directory (i.e. if they are strong named make sure you DO put them in the GAC).
ASP.NET Memory - You use the same dll in multiple applications, is it really necessary to load it multiple times?
Wherever possible strong name and install to the global assembly cache (GAC) any assemblies that are used by more than one ASP.NET application. This will ...
ASP.NET: Check your Web Site today for these common assembly related memory and perf issues
Recently my colleague Doug wrote a nice post on Nine tips for a healthy “in production” ASP.NET application.
.Net memory leak: Unblock my finalizer
This time I figured I’d talk about an issue that spans all three debugging scenarios, hangs, memory issues and crashes… yummy :)
It’s been a while
Hi All,
ASP.NET Performance Case Study: Web Service calls taking forever
This issue has been pretty frequent since .net came out, and I am bringing it up for two reasons.
.NET Memory Leak: XmlSerializing your way to a Memory Leak
I hate to give away the resolution in the title of the blog since it takes away a lot of the suspense :) but I can’t figure out a better way to name the blog...
.NET Crash: Managed Heap Corruption calling unmanaged code
If someone asked me, what is the nastiest types of issues you get? I would say managed heap corruption, closely followed by native heap corruption.
A .NET Crash: How not to write a global exception handler
I’ve written quite a few posts on memory issues because that is the type of problem we get most frequently in support, but I thought I’d break it up a little...
.NET in SQL Server 2005 – Making .net code more reliable
A while back I got interested in the new .net/CLR features in SQL Server 2005 such as .net stored procedures, functions, triggers etc.
.NET Memory: My object is not rooted, why wasn’t it garbage collected?
I got a comment on one of the posts asking this question and I started writing a comment-answer but it turned into a long-winded rant so I decided to blog it...
ASP.NET Memory Leak Case Study: Sessions Sessions Sessions
In ASP.NET 1.1 as you probably know, there are 3 different locations to store session objects.
Contacting Tess
I have been receiving a lot of email lately asking for help on particular issues.
A bag of chips – Math stuff… and books…
This is a completely off topic post but I added the “–and a bag of chips” to the blog description to allow myself to write these:)
ASP.NET Memory - How much are you caching? + an example of .foreach
I was writing a post on debugging a high memory usage problem caused by storing too much in session scope, but I realized I got in to tangent discussions all...
.NET Memory Leak Case Study: The Event Handlers That Made The Memory balloon
It always feels like issues come in clusters. One week we get tones of cache related cases, next week everyone is stuck in some lock and so on. Lately I have...
Request for feedback
Not sure if anyone is reading this blog, but if you are and there is something specific you want me to blog about please let me know.
Debugging Tips: Use windbg as a calculator, a chat client and more…
Yes, you read it right… it’s not only a debugger, for only $19.95 extra, we’ll throw in a free calculator and chat client:) and you can even run applications...
Back to Basics - How do I get the memory dumps in the first place? And what is SOS.dll?
Windbg.exe and its friends can be installed from here
A Hang Scenario, Locks and Critical Sections
The situation here is that the server at times slows down considerably, or even hangs completely. Requests start timing out and no new requests seem to be ge...
Things to ignore when debugging an ASP.NET hang
When looking at a dump, a lot of the art of debugging (I like to call it an art because it makes me feel more important:)) is knowing what you can ignore so ...
Why do I get weird function names on my stack? (a discussion on symbols)
Symbols can contain information about global variables, local variables, function names, parameters, structures and source line numbers.
Associate windbg with .dmp files
If you get tired of starting the debugger, loading your dump, setting up your sympath, loading your extensions, etc. etc. here is a nifty way of getting “Deb...
Are you aware that you have thrown over 40,000 exceptions in the last 3 hours?
This may seem like a preposterous statement, but unfortunately it’s all too common.
What on earth caused my process to crash?
So you got a 1000 w3wp.exe stopped unexpectedly in the event viewer or your process just exited in some weird undefined way and you don’t know why.
!dumpheap –stat explained… (debugging .net leaks)
The most powerful command when debugging a managed memory leak is by far !dumpheap. It will show you all the objects on the managed heaps and using the diffe...
I have a memory leak!!! What do i do? (defining the where)
Not that it matters a tremendous lot but just because it is a big pet-peeve of mine I want to differentiate between a real memory-leak and high memory usage.
Who is this OutOfMemory guy and why does he make my process crash when I have plenty of memory left
To answer this question, there are a few concepts we need to discuss.
Why I love the debugger
10 years ago, still in college, I started working for a company developing real-time systems for trains in Motorola HC11 assembly. Although very interesting ...