I'm trying to use EQATEC Profiler to profile my ASP.Net app. I followed the instructions listed here. It worked the first time, but every since then, when I run my app, I don't get a "Profiled app started" message. Then when I click on the "Take snapshot" button, I get the following:
"Taking snapshot ...failed: The remote server returned an error: (404) Not Found."
Why can't it find my app?
If a profiled app encounters errors it will log these to the profiler.log file. By default you will find this in C:\Windows\Temp\EQATECProfilerLogs. Try to see if it holds some clues. You can also try to enable "Full logging" in the app options, which will at least output something to the log.
A profiled app is actually the "server" when talking to the profiler; it is the profiler that connects to the app, not the other way around. In your case it seems that the old app has stopped listening (otherwise the profiler's attempt to connect would simply be served by the old app), but the new app has not (could not?) started listening.
It seems strange, though, so my best suggestion is to examine the log-file. It will e.g. show if the app could not start its control-server and if so, why not.
1) Try rebuilding (in Equatec) your application. Make sure "enable runtime control" is enabled in the application options when you build.
1a) Try changing the port being used for runtime control.
2) Run your application through Equatec
3) Check if you have anything funny for firewall settings or similar. Some firewalls treat Equatec communication as traffic to be blocked.
4. If all else fails, just close your application normally. Even if taking snapshots fails, you can still see the profile once your application is closed.
Guess I should provide an update on this. The error was resolved once I downloaded the latest version.
Related
We are developing an (internal) web service based on asp.net 4.8, with a fairly extensive REACT SPA front end.
For debugging purposes during development, we run an IIS server on the local (development) machine, and we do something separate to run a proxy web server for debugging the .js front end SPA (not relevant to the question at hand).
When we start up a Debug session in Visual Studio (2019), VS starts with "Contacting web server to start debugging" and then locks for a time. It clearly does something to start the web server (w3wp.exe), and waits for some reply, before doing what it is told to do in the "Start Action" section of the Web tab on the project properties page.
This is problematic behaviour because it does not attach to w3wp.exe until after it finishes it's "contacting web server to start debugging" operation. This is a huge problem, as our w3wp.exe starts doing all kinds of things that we have no visibility into.
So, can anyone explain to me:
What does VS actually do to "contact the web server"?
Can this be controlled? If so, how?
Can I get the debugger to attach to w3wp.exe right away?
Why does w3wp.exe start up and load its collection of binaries, only unload them and reload them, sometime multiple times?
In short, what the actual heck is going on under the covers at startup?
This (Identity Server 3 Contacting the web server hangs when launching debug mode) question and answer seem irrelevant to my situation
I note the field Override application root URL in the Servers section of the Web tab of the project properties and had hoped this might have something to do with it, but I cannot see any relation.
Partial answers that I will either edit as I find more info, or modify if others correct me, or delete if someone answers completely. The answers to (1) and (2) above are this:
VS obtains the URL of the target web site (I will call this targetServer) from the Project URL entry in the Servers section, Web tab, of the Properties page for the web project. This actually comes from the <webProjectName>.csproj.user file in the project directory. Depending on the selection of the drop down specifying the server type to use, it comes from:
IIS server (<UseIIS>true): the <IISUrl> element
External Host (<UseCustomServer>true): the <CustomServerUrl>
IIS Express: unknown
WARNING: When opening a project with <UseIIS>true, Visual Studio has the very nasty habit of interfering in the setup of your IIS server: it insists on changing the "Physical Location" attribute of the IIS server (that is, the server or virtual app, however you have it set up) to point to the project directory of the web project. Using the "External Host" option avoids this - see https://stackoverflow.com/a/48753054/1082063. (All other discussions of this issue that I have seen incorrectly say this cannot be controlled.)
VS then issues a request to the url <targetServer>/debugAttach.aspx, and the request shows as neither a "GET" nor a "POST", but a "DEBUG", whatever that is. Not sure what VS expects back from this before doing the specified Start Action
Presumably after VS gets some reply from its DEBUG request, it will attach to the process that resulted from this request. Not sure how it knows which process to attach to - perhaps the debugAttach.aspx returns process information?
VS finally executes whatever Start Action is specified in the section of that name on the Web tab of the project Properties.
I strongly suspect that the answer to (3) above is that one cannot get VisualStudio to attach any earlier than it does because it must use the information returned from the debugAttach.aspx request to know which process to attach to. However, putting the line System.Diagnostics.Debugger.Launch(); at the start of Application_Start will allow you to attach the debugger earlier when necessary. (In practice, once you get Application_Start correct, you seldom need to debug it.) See this: https://weblog.west-wind.com/posts/2011/Dec/15/Debugging-ApplicationStart-and-Module-Initialization-with-IIS-and-Visual-Studio for a very good article on the subject.
(4) was a result of quirks in our Visual Studio setup. The initial "hack" used to get around the WARNING in answer (2) just above, was to have a web site with a dummy "virtual path" and have the IISUrl element in Visual Studio point to this virtual path. Then VS could change the Physical path of this virtual path, and we didn't really care, because our Start Action was to start a proxy server for debugging .js in any case. The issue was that this resulted in two calls to Application_start, running on two separate threads: one for the main server and one for the virtual server. Because one of these was happening before the attach happened, we never knew it was happening and it was never caught in a break point. When our application_start became long (timewise - this is not a web server for public consumption...), the two executions of application_start became a nightmare.
The issue you're seeing in IIS is that VS is not launching w3wp.exe, but rather Attaching to Process. In order for VS to attach though the EXE has to be running first, and the time between starting up and attaching (if not already running) ends up being too late to catch the ASP.NET app initialization logic in Application_Start and Module initialization.
As mentioned in my old post there are several ways you can get this to work:
Restarting the application when the debugger is already attached
(by making a change in web.config to trigger an AppDomain reload)
Adding an explicit Debugger.Break() call in Application_Start
Use IIS Express to debug startup code
I have an API in a .NET project that I'm running with Visual Studio Mac (8.4.3). I run it in release mode, and it opens a browser window with localhost:5000. The browser window says "ok". However, when I try to hit endpoints in that API, it fails very quickly. When I ran this API (ie. same code) from another server and accessed it via proxy, it ran fine. For example, when I ran it on a server whose IP was 162.250.198.98 and proxied into it, I would hit an endpoint like 162.250.198.98:3000/api/user and it would work, but now when I try to run localhost:5000/api/user, either from my app or from Postman, it fails almost instantaneously. When running it in Postman, I tried what it suggested by turning off 'SSL certificate verification' in Settings, but no change.
Can anyone advise me on how to approach troubleshooting this?
Wait, so You are saying that while trying to call API on 162.250.198.98:3000/api/user You are fine but while trying to do the same thing on localhost:5000/api/user You are getting an error? Would it might be possible You have Your API configured to receive calls at 3000? :)?
No, but really - please chech it out, maybe it is that simple, I'm couting on it :).
You can change/check it in Visual Studio: main project > Properties > Debug > App URL.
I have an application that runs perfectly fine locally using the VS 2010 application server, however, when I deploy to our web app machine startup just spins and spins and never loads. We have other apps on this same machine that load just fine (this is a debug deployment of same app in product).
I have been spinning my wheels on this for days and I am at a loss as the problem could be.
Here is what I did
Create a new directory (same level as other apps)
Copied over our existing test (www.domain/test/) and it works fine
Build and publish new debug app (www.domain/test/) and it just spins trying to load first form.
I know the diretory is "working" as the 'test' application I put there works fine.
If it's killing the App pool, you might get something in the event log. Fiddler (www.fiddlertool.com) is great http debug tool which let you see if you're in a redirect loop. Also Firefox shows a more meaningful error, something about exceeding the max redirect count.
It does sound like something is looping, but not quick enough to cause a stack overflow, which is odd, because you'd expect it to fail every time.
Simon
Do you have the ability to remote desktop into the machine? If so try running process explorer and look at the process details for the worker process that is giving you issues. Definitely look at the TCP connections being created. If your processor is pegged at 100%, and memory usage is rising then you probably have an endless loop running.
It sounds like it's more related to IIS than ASP.NET. What about the identity that the website is running under? Is it possible that the user the site's running under a bad user, or maybe the password needs to be re-entered?
I did a quick Bing search
There are a lot of postings regarding the error message you described above. Most if not all point to code in your app that is crashing. I know I had a similar problem when I used an automated/threaded daemon utility in my web application. Make sure your code is not bringing down the server, sometimes the VS2010 web server is a little more foregiving than an actual IIS deployment.
If that doesn't work try running a Remote Debugging Session to try and catch any errors being thrown but not handled.
Lastly you could try to setup a new local IIS server to see if you have the same problems. Scott Gu has a nice article about using IIS Express to do this.
I've written a c# windows app, that performs some DB intensive operations. (MySQL connector v6).
When running the project in Debug mode, everything works fine. However, when I run the prject in release mode, it sometimes quits operation midway - with no error message, nothing in the event logs etc.
What would be the best way to debug release mode - when everything works in debug mode?
Thanks for any help,
Bob
You can create a log file and have the application write lines to it with information of your choice, similarly to how the console may be used for debug purposes in a windows form application. You can write values of certain variables to this file, or even just write distinct phrases in select places of the code that will help you detect where the program is in execution when it fails.
Bobby is correct in asking about Application Event Log. If it is bombing on a .NET error, it will likely be logged.
If that doesn't give you anything, wrap the entire app in a try/catch block. On your exception handling, log the error (application log, file, etc...). Make sure when you log it to capture the call stack.
I've got exactly the same problem - application running in debug mode and fail in release. Try the following:
Wrap everything in Program.cs in try{}..catch{} block and it will show a reason
I don't know why but my application failed on Program.SetCompatibleTextRenderingDefault() function with message that it should be called before any instances on IWin32Window or something like that
It is very strange errors for me cuz i didn't have any code before this function. But you can try - maybe it will show something useful for you
This may seem like a silly question, but we are having an issue debugging IIS in a shared test environment and I'm hoping that someone out there can give us an answer.
We have a Windows Server 2003 that is running IIS 6 and sharepoint 2007. We are debugging locally on the server with visual studio 2008.
When someone attaches the debugger and steps through the code, we find that all users are affected. In essence the web server stops handling all requests from all users.
Our question is whether this is a typical situation and is to be expected? Or is there some configuration that we can change that would allow the one user's session to be debugged but leave the other's unaffected.
Kev's on the right track. You need to make sure that the project you want to debug separate from the others is in its own application pool. This will isolate it to its own process and allow that process to be stopped/debugged without affecting the other applications which can remain in a different pool.
Setup
Start -> Run -> inetmgr
Right Click on Application Pools
Click New -> Application Pool
Name the new pool
Right Click on the application you want to isolate
Click Properties
Click on the Home Directory tab
In the application pool drop-down list select your new pool
Click OK
If there are any requests queued in the old process, they may take a few minutes to terminate before all requests are being diverted to the new process.
Debugging
To figure out which instance of w3wp.exe you need to attach the debugger to:
Start -> Run -> cmd
Type iisapp
You may be prompted to register CScript, if so click yes and run it again
The only gotcha you may still find is that if multiple applications are using the aspnet_state service you may run into blocking issues if you need to debug that process as well.
Links
MSDN
Developer.com
"When someone attaches the debugger
and steps through the code, we find
that all users are affected. In
essence the web server stops handling
all requests from all users."
This is normal, once you attach a debugger to a process such as inetinfo.exe or w3wp.exe and set a break point, every request/thread will be blocked until you allow the debugger to continue, until the next break-point.
I've never found a way around it. Is there some reason you can't debug on each developer's workstation?
Set up a parallel project on the server and try using that. You could use debug.mydomain.com and then just use that for testing. The only reason that I personally can think of to debug on your live servers is if there is a significant difference in the functioning of your app due to either hardware or software configuration.
Ideally you want to have a separate server/instance of your system in as similar an environment as possible so that you don't have to debug on your live machine. Also you might want to consider writing all errors to the event log or at least checking the log since asp.net usually get logged there. This way you can see where your errors are and use that to help you solve your problem in the development environment.
I believe in visual studio you can set the debugger to break only the process being debugged, and not all the processes. Depending on how your system is set up, YMMV with this.
It can't be changed AFAIK. But that's a normal practice to set up separate web-node or web-application for development/debugging purposes. If that's necessary to know exact values of some vars in certain situations you can always use debug logging.