 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
.NET Forum / .NET Framework / New Users / December 2005Last effort to solve threading issue
Been working off and on with this for quite some time with no luck. Last request before scrapping it. Using a web service running framework 1.1 I'm creating threads and making http calls within them. The problem I'm having is that I get 2 exceptions (can't narrow down to a particular line of my code - none of my exception handlers catch it) when the http calls take a long time (which they do consistently): <AbbreviatedStack> [AppDomainUnloadedException]: Attempted to access an unloaded AppDomain. at System.Threading.Thread.SetCompressedStackInternal() at System.Threading.Thread.SetCompressedStack() at System.Xml.XmlTextReader.CreateScanner() at System.Xml.XmlTextReader.Init() at System.Xml.XmlTextReader.Read() at System.Xml.XmlReader.MoveToContent() at System.Web.Configuration.XmlUtil.OpenXmlTextReader() at System.Web.Configuration.HttpConfigurationRecord..ctor() [ConfigurationException]: The XML file [machine.config] could not be loaded. Attempted to access an unloaded AppDomain. at System.Web.Configuration.HttpConfigurationSystem.CacheLookup() at System.Web.Configuration.HttpConfigurationSystem.ComposeConfig() at System.Web.HttpContext.GetCompleteConfigRecord() at System.Web.HttpContext.GetCompleteConfig() at System.Web.HttpContext.GetConfig() at System.Web.HttpContext.GetMachineConfig() at System.Web.HttpContext.GetAppLKGConfig() </AbbreviatedStack> I've tried all sorts of things like: - Modified ASP.NET settings - Reinstalled the framework and hotfix. - Tried Thread.Sleep(0) in various places hoping to prevent some kind of deadlock. Is there a threading issue in general or any other clue someone might have for me? - desperate. I don't know but... this "The XML file [machine.config]" looks very suspicious. it should be located here: <WINDOWS>\Microsoft.NET\Framework\v1.1.4322\CONFIG\machine.config If not.. maybe reinstall? Also I will try to make an uneducated guess. Maybe your threads have a longer lifespan that the method which initiate them and the ASP.NET engine has unloaded the domain or something like that? > Been working off and on with this for quite some time with no luck. Last > request before scrapping it. [quoted text clipped - 37 lines] > > - desperate. > I don't know but... > this "The XML file [machine.config]" looks very suspicious. > it should be located here: > <WINDOWS>\Microsoft.NET\Framework\v1.1.4322\CONFIG\machine.config Sorry, I was trying to trim the stack dump; it is located in the proper location. > Also I will try to make an uneducated guess. > Maybe your threads have a longer lifespan that the method which initiate > them and the ASP.NET engine has unloaded the domain or something like that? This is very logical, but doesn't seem possible since I'm calling join() on every created thread before returning from the main WS method. After all this time, I have new evidence: Formerly, the error would consistently occur every other time I called the WS. It didn't seem to matter how many http requests I made as long as there were more than about 15. Because these trials took so long, and because it didn't seem to matter exactly how many requests were made, I would browse the Internet while they were running. Today, I was unable to reproduce the error as long as I didn't do anything else on my machine while they ran. The first time I ran a test and browsed the Internet at the same time, it occurred again. This really doesn't point me in any further troubleshooting direction though... Brad, are you sure you are not hiding any exceptions inside your code? Is it only browsing that creates the problem or any a bit bigger app does the same? Could be a resource related problem if so. Laura >> I don't know but... >> this "The XML file [machine.config]" looks very suspicious. [quoted text clipped - 25 lines] > This really doesn't point me in any further troubleshooting direction > though... > are you sure you are not hiding any exceptions inside your code? Do you mean am I gobbling some exception that should more properly be raised? If so, I don't think so. When I wrap the entire WS method in an exception block, the error still occurs. This would seem to indicate that the error is occurring within the ASP.NET engine outside the scope of my code. > Is it only browsing that creates the problem or any a bit bigger app does > the same? > Could be a resource related problem if so. My previous data now no longer applies. I would have thought that the following would have narrowed it down: - Error occurs every other WS call for *countless* attempts while browsing Internet frequently during trials. - Unable to reproduce error while not touching my machine for 10 straight trials. - Error occurs very next attempt while browsing Internet on my machine. but... I tried again to double check and did experience the error while not touching my machine during the trial. Brad, I guess you have a resource leak somewhere, like missing dispose or too long held references. Check with performance monitor the handle and memory usage. Laura >> are you sure you are not hiding any exceptions inside your code? > [quoted text clipped - 19 lines] > but... I tried again to double check and did experience the error while > not touching my machine during the trial. > I guess you have a resource leak somewhere, like missing dispose or too long > held references. > Check with performance monitor the handle and memory usage. If I see something in PerfMon, where do I look in code? I've scoured the project (it's good sized, but not massive) for proper usage of resources. Of course during the http calls HttpWebRequest objects and stream readers for GetResponse are open for a long time, but I can't change that. The calls are made to a very slow intranet resource. Considering my errors (below), it seems that there is some timeout somewhere that I'm unaware of: - "machine.config could not be loaded" (in tandem with either "Attempted to access an unloaded AppDomain" or "Resource lookup failed - infinite recursion detected". - When hosted remotely, I just get "http request timed out". I think those errors are related only to the long execution time, not to my code particularly. - The http timeout can't be from my code because my HttpWebRequest timeout is set to Timeout.Infinite (during testing anyway). - The infinite recursion seems to be something going on inside the ASP.NET engine trying to get to the machine.config. This error only happens when the http requests take a long time. So I'm thinking that in the OS there is some http timeout or in the ASP.NET engine there is some timeout that causes an AppDomain that a thread is running in to be unloaded (or some other such thing I have no control over). Thanks for the help. My next step is to use the http asynchronous calls rather than creating my own threads. Hopefully there will be a difference between the threads the framework creates and mine... Hi Brad, I put my two cents here: executionTimeout in the web.config file? Make it huge or your appdomain will be teared down with that exception. Tried to disable virus scan software? There are some notes regarding a few vscan programs that can give problems with .NET 1.1. Laura > Been working off and on with this for quite some time with no luck. Last > request before scrapping it. [quoted text clipped - 37 lines] > > - desperate. > executionTimeout in the web.config file? Make it huge or your appdomain will > be teared down with that exception. Already tried that; tried it again just now to be sure (both app.config and machine.config). No luck. > Tried to disable virus scan software? There are some notes regarding a few > vscan programs that can give problems with .NET 1.1. Tried disabling and uninstalling. No luck. Thanks. Free MagazinesGet these publications absolutely FREE for up to 12 months. There are no hidden fees and no obligation. Simply choose a title, complete the application form and submit it. Read more ...
|
Reply to this Message
|
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.