Customer has COM+ application running on Windows Vista SP2. Found memory keeps increasing. After enabled Memory Leak tracking on application process by DebuDiag, we canptured memory dump successfully. From the memory dump, using DebugDiag Analsyis: 1. Found the leakage pattern points to the functions...

Customer reported one High CPU issue while one ASP.NET application is under normal load. Regarding ASP.NET application, besides the multiple threads busy, tighten looping code defect some general possibilities, looking at the memory usage is quite important because heavy memory pressure may lead...

Symptoms ======== My customer receives the following response intermittently: Request timed out. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated...

NOTE: The following steps apply to ASP.NET 4.0 (64 bit). They have not been tested in other versions of ASP.NET. (For ASP.NET 2.0 32 bit, please refer to http://blogs.msdn.com/b/asiatech/archive/2011/07/06/how-to-troubleshoot-httpexception-request-timed-out-asp-net-2-0-32-bit.aspx ) Symptoms...

Recently I faced one IIS Admin starting failure issue. When customer tried start IIS Admin Service, the service was pending on starting, and then failed. If we check the event log, we will see: Event Type: Error Event Source: Application Error Event Category: (100) Event ID: 1000 Date: 3/31/2012 Time...

Many services run in the SVCHOST host process rather than under its own executable. Because of this, it may be difficult to dump a particular service unless you are able to isolate that particular service from the other services loading under SVCHOST . For examples: if Winmgmt services is suspected of...

Symptom =========== When visiting an ASP.NET application for the first time, it is rather slow. It might take a long time from dozens of seconds to several minutes. Root Cause ============ In ASP.NET web application, if you use some Authenticode Signed .NET assemblies, the application...

This is an ASP.Net 2.0 application experienced stack overflow on both X86 and X64. Same again, we captured crash dump file to find out the reason of stack overflow. Here is the edited output of fault stack. 0:014> kL ChildEBP RetAddr 01cd3d80 7a0363d7 kernel32!RaiseException+0x53 ...

This is an ASP.Net application running on IIS 7. The application hangs with 50% CPU every time making a change to web.config. C ustomer has to restart IIS services to resolve the problem. Changing web.config during application running is not a good idea since this triggers application domain recycle...

I had an interesting case recently. We discovered a hang in ASP.Net application caused by string.IndexOf method. Problem description: Frequently, this ASP.Net application would hang and the IIS worker process needs to be restarted for the application to function correctly. This happens even when...

Some users want to remove certain HTTP headers in IIS 7.0/7.5 to avoid divulging platform information through response headers. They usually implement a custom HTTP module and remove the headers in PreSendRequestHeaders notification. public void Init(HttpApplication app) { app.PreSendRequestHeaders...

When multiple .NET runtime are loaded in one target process or one dump file, for example: 0:030> lm start end module name 00000000`1b6d0000 00000000`1b9ba000 System_Data (deferred) … 000007fe`f3e60000 000007fe`f47c5000 clr (deferred) … 000007fe`f9880000 000007fe...

Customer has a scheduled task to upload a picture to FTP server at fixed time every day. The whole server will hang for several minutes as long as the task was executing. During this period, there was no response to keyboard and mouse. The performance counters were blank as well during that period. ...

Customer has an ASP.Net application uses XmlSerializer. The XML serialization infrastructure dynamically generates assemblies(by calling CSC.EXE) to serialize and deserialize specified types. By default, the assemblies will be created under %TEMP%. The file name is random generated by CSC to avoid conflict...

Heap corruption is by nature a complicated issue to troubleshoot and in some cases luck is as important as debugging knowledge as well. I got an assistance request from one customer saying that they encountered a W3WP process crash intermittently. He reported that the server was indeed under heavy load...

I was recently engaged in a consulting project sponsored by one Premier customer. The project is kinda SOA and will leverage Microsoft SOA technology Windows Communication Foundation (WCF). The project as a whole may be composed of several different consumers for instance ASP.NET web application, WinForm...

1. TlsAlloc failed with TLS_OUT_OF_INDEXES 2. Web Application Memory leakage caused by XML operations - GetElementsByTagName() 3. Web Application Memory Leakage Caused by BSTR 4. Maxconnection failed to take effect

Symptom =========== Customer built an ASP.NET web application using Visual Studio 2008 on Windows 2008. In the source code, it called a function which was imported from native c++ dll: [The source code looks like below] public partial class _Default : System.Web.UI.Page { protected...

Background: ========== Customer experienced the high CPU utilization with their ASP.NET application and the CPU will fluctuate. Analysis: ========== We found a lot of exceptions generated and this could severely impact the application performance. We got the crash dump which signified...

When you make calls to Web services from an ASP.NET application, you may experience contention, poor performance, and deadlocks. Clients may report that requests stop responding (or "hang") or take a very long time to execute. One very common cause is the maxconnection parameter that the System.Net...

Symptom ============ Customer has one COM+ application running in Windows 2000 well for long time. After moving this COM+ application to Windows 2003 SP2, they noticed that the COM+ application easily hangs under heavy load. Captured dump files for analysis. When issue happens, multiple STA...

Three months ago, I have a blog talking about worker process affinity . Now, we have a similar issue again, but it is more complex this time. My customer has SQL reporting service installed on an 8 CPU windows 2008 system. And he experienced severe performance issue as soon as the application started...

It is an ASP.NET application and randomly experience 100% CPU issue. We can’t get a relief until restart the worker process. To troubleshooting this problem, we collected two dumps one CPU is high. But compare the “!runaway” results, we find several threads consumed most of the...

Symptoms: IIS Manager hangs up on the loading procedure after the OS upgraded from Windows 2000 to Windows 2003. Customer could open IIS Manager but found it hang when right click any item on the left pane. Meanwhile, customer could still browse web pages from the clients. Analysis: ...

Symptom ============= In ASP.NET web application, if you do a lot of GetElementsByTagName() operations with an XML document which is stored in ASP.NET Application state, the CLR memory usage will continuously increase and finally leads to OOM(Out Of Memory). Root Cause ============= ...