ASP.NET Memory: Thou shalt not store UI objects in cache or session scope Surprisingly the issue I wrote about in " the eventhandlers that made the memory baloon " (Jan 2006) is something that still happens very frequently, I reference it in cases at least a few times a month.  Just this last week I had different variations of it crop up in different cases so in this post I will show a different variation, what to look out for and how to identify it. Problem description: The issue...

The guys at Oredev are in the midst of preparing for the next Oredev conference in November. Sadly I won't be presenting there this year because of other comittments. I say sadly because it was an awesome event last year. If you want to check out my presentation from last year you can do that here . The page says "Due to technical problems with our video equipment, this session was never recorded" but that is incorrect. The video is there... Disclaimer: I had some issues with the mike not fitting...

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 that if I started writing about them, a lot of people would be able to resolve them on their own, or even better avoid them in the first place. A lot of water passed under the bridge since then, but looking back at some of those earlier posts they are still very applicable today, and they still seem to continue to get a lot of hits. Here is a...

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 from the developers of debugdiag when I suggest using adplus and windbg on internal discussion lists, and to be fair I have to beat on the drum a bit for debug diag as well. My answer to the question "Should I use DebugDiag 1.1 or Windbg" is both... it just depends on the scenario. I often lean towards windbg but to a large extent that is because...

Issues caused by frequent application restarts are pretty common. If you are interested in what causes application restarts in general, and how you can monitor application restarts and what causes them you should read this post: ASP.NET Case Study: Lost session variables and appdomain recycles The most recent one was one where the ASP.NET site would respond slowly at regular intervals (read: it grinded to a halt every few hours). First shot at gathering data: We started off by getting a memory dump...

I just came across this great post from Mike Volodarsky (a program manager in the IIS team) about breaking changes when you move 2.0 applications to IIS 7 . It is definitely worth a read before you make the switch so you can take appropriate actions to avoid running into problems. Laters, Tess

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... Failed to start stack walk If you run the sos command !clrstack to display the .net stack on a thread, and this thread is a .net thread but it is not currently running any .net code, sos will spit out Failed to start stack walk: 80004005. This does not mean that there is anything wrong with the process or with the debugger. It simply means that sos can...

When you use authenticode signed assemblies in an application, the application needs to go out and check the certificate revocation lists (CRLs) to verify that the signature is still valid the first time it loads up the authenticode signed assembly. If the server, serving your asp.net application, doesn't have internet access or if the internet connection is slow this can lead to issues where you stall the process during startup or when the assembly in question first loads. What you will typically...

Today I came across a really good article for bloggers, Scott Hanselmans post on " Blog Interesting - 32 Ways to Keep Your Blog from Sucking " (update: for some reason the link gives an xml error, should be http://www.hanselman.com/blog/BlogInteresting32WaysToKeepYourBlogFromSucking.aspx if the link above doesn't work) I realize that most of you are not bloggers, and also that I am breaking rule #7 and #8 on the list here:) 7. Don't post throwaways I try to have a minimum length...

I very frequently get emails like the one I got this morning: "Tess, It sounds like the hotfix for kb946644 may resolve a problem we've been having for some time in .Net 2.0. How, exactly, can we get this hotfix? Can you provide it?" This particular hotfix was one i blogged about here, regarding a deadlock with the GC when using XmlSchemaSet.Add... but the answer will be the same for any hotfix. Many new hotfixes in the Visual Studio or .net framework area are available for public download by the...

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, performance issues, OutOfMemory exceptions, garbage collection, troubleshooting. Those are the things that I think, but I might be wrong, that people who visit my blog are most interested in. As with most other technical blogs (I think), about half of the traffic to my blog comes from people searching on various search engines, but what really surprised...

I have written a few posts about stackoverflow exceptions, here, here , here and here . The one I am going to talk about today is one of those unfortunate cases where you are trying to do the right thing and still shoot yourself in the foot. Problem description: Randomly when browsing the application we get the "Internet Explorer cannot display the webpage" page, and the following event is found in the system eventlog Event Type: Warning Event Source: W3SVC Event Category: None Event ID: 1009...