NetExt – SOS on steroids


I have been playing recently with quite a new windbg extension (released by Rodney Viana from Microsoft) called NetExt. Rodney Viana published an introductory post about it, which you may find on his blog. In this post I would like to show you my usage samples as well as encourage you to start using it by yourself. Netext documentation is thorough and nicely organized which is good because at the beginning you probably will spend a lot of time on this page :) In paragraphs that follow I will focus mainly on dump debugging, but most of the techniques presented here should work as well in live debugging sessions.

Continue reading “NetExt – SOS on steroids”

NetExt – SOS on steroids

How to debug Windows Services written in .NET? (part II)


This post is the second and final one dedicated to debugging .NET Windows services (you may read the first one here). The inwrap tool (presented in the first part) is not very friendly to use and I myself haven’t used it since then :) It’s not the best advertisement of someone’s own work, but it did motivate me to write another tool which maybe will gain your interest. The winsvcdiag is a simple application that allows you to debug a start of a Windows service from Visual Studio (or any other debugger – even the remote one).

Continue reading “How to debug Windows Services written in .NET? (part II)”

How to debug Windows Services written in .NET? (part II)

A case of a deadlock in a .NET application


I recently had an interesting issue in one of our applications. The SMS router, responsible for sending and receiving SMSes, hanged – there was no CPU usage and we haven’t observed any activity in the application logs. I collected a full memory dump and restarted the service, which seemed to come back to its normal state. Curious what happened I opened the dump in WinDbg, loaded PDE and SOS and started an investigation

Continue reading “A case of a deadlock in a .NET application”

A case of a deadlock in a .NET application

Timeouts when making web requests in .NET


In one of our applications I recently observed timeouts in code performing HTTP requests to the REST service. While investigating this issue I discovered few interesting facts about System.Net namespace and would like to share them with you. We were using objects of type System.Net.HttpWebRequest in our code, but some of the information presented in this post will also apply to the newer System.Net.HttpClient implementation.

Continue reading “Timeouts when making web requests in .NET”

Timeouts when making web requests in .NET

How to debug Windows Services written in .NET? (part I)


Diagnosing Windows Services might sometimes be cumbersome – especially when errors occur during the service start. In this two-parts series I am going to show you different ways how to handle such problems in production. In the first part we will focus on “exceptions discovery” techniques which very often are enough to figure out why our service is not working. In the second part we will setup a debugging environment and attach a debugger to our service. Let’s start then.

Continue reading “How to debug Windows Services written in .NET? (part I)”

How to debug Windows Services written in .NET? (part I)

Common authentication/authorization between .NET4.0 and .NET4.5 web applications


ASP.NET Identity is a big step forward and we should profit from its features, such as: two-step authentication, support for OpenId providers, stronger password hashing and claims usage. One of its requirements is .NET4.5 which might be a blocker if you have in your farm legacy Windows 2003 R2 servers still hosting some of your MVC4 (.NET4.0) applications. In this post I would like to show you how you may implement common authentication and authorization mechanisms between them and your new ASP.NET MVC5 (and .NET4.5) applications deployed on newer servers. I assume that your apps have a common domain and thus are able to share cookies.

Continue reading “Common authentication/authorization between .NET4.0 and .NET4.5 web applications”

Common authentication/authorization between .NET4.0 and .NET4.5 web applications

Collect .NET applications traces with sysinternals tools


In this short post I would like to show you how, with sysinternals tools, you may noninvasively trace .NET applications. This is especially useful in production environment where you can’t install your favorite debugger and hang whole IIS to diagnose an issue. We will work with three tools: dbgview, procdump and procmon. Let’s start with the first one.

Continue reading “Collect .NET applications traces with sysinternals tools”

Collect .NET applications traces with sysinternals tools