My application is deployed on IIS 7. I want to check the number of failures as my logic is getting failed at some point and getting errors.Is there any general weblogs in IIS.I can only see system errors in the event logs. Is there any web logs?
Manually trawling the standard W3C logs is ok if you're chasing down requests for certain content types, but they won't tell you an awful lot about why your web application is failing and responding with many 4XX and 5XX status codes. You'll get a status code, but that's about it.
Failed Request Tracing:
Your "go to" diagnostic tool should be the Failed Request Tracing feature that is built into IIS7+.
FRT is one of my favourite features of IIS7/8 for tracking down problems with production sites, especially when debugging apps built on the WebAPI and Ajaxy type stuff.
For more information see:
http://www.iis.net/learn/troubleshoot/using-failed-request-tracing
For example, last week FRT helped me get to the bottom of an issue with a client's hosted site. A particular part of the site (which uses the WebAPI) was failing with a 405 Method Not Allowed status code when making a HTTP DELETE request and despite the DELETE verb being permitted.
Using FRT I was able to generate trace of the failing request which showed me this:
Expanding the "View Trace" entries revealed this error:
The solution for our customer was to disable (it's not used) the WebDAV native module which doesn't permit non-Windows authenticated requests with certain verbs (such as DELETE) to complete. Even if the WebDAV module isn't handling the request it's still in the request pipeline inspecting and validating request headers.
Failed Request Tracing is a really invaluable diagnostic tool, you should learn how to use it.
The HTTPERR Logs:
You should also check the HTTPERR logs located in:
C:\Windows\System32\LogFiles\HTTPERR
If you get 503 - Service Unavailable errors they're a good place to look for clues as to what went wrong if an application pool fails catastrophically, and often.
The is a folder named 'logs' in your 'inetpub' folder where all the logs live. You can look at the Logging tab under IIS in IIS Manager to see the name of the specific log you should check for your site.
Related
This is a similar post to Azure Web App Trace logs not appearing in log, however the original poster seems to have abandoned the question without resolving/accepting an answer.
I am trying to trace an issue that only happens on the Azure web app (now called app service). I'm unable to perform any remote debugging due to our company policies, so tracing is our best tool.
However, I've tried following various tutorials, but I still can't seem to get any of my trace information logged.
I've tried:
Setting the Application Logging (Filesystem) Level to Verbose, Information, Error -- nothing.
Looking for the logs in
the FTP server at /LogFiles/Application
the KUDU interface at https://.scm.azurewebsites.net and again, navigated to /LogFiles/Application
portal's Monitoring > Live stream (the section under Diagnostic Logs for the website)
Nada. I've even waited a few hours (thinking it might be a delay), and still nothing.
I setup a very basic hello world ASPX and all it does (in the Page_Load) is try to write 'hello' to the trace log using
Trace.TraceError
Trace.TraceInformation
Trace.TraceWarning
Trace.WriteLine
Console.Out.WriteLine
Console.Error.WriteLine
Some weird stuff I've also tried
setting my debug=true in my web.config
setting CustomErrors from RemoteOnly to Off
trying to use System.Diagnostics.TextWriterTraceListener
Anyone have any ideas I might try?
Exceptions in your live web app are reported by Application Insights. You can correlate failed requests with exceptions and other events at both the client and server, so that you can quickly diagnose the causes. You may refer this article: https://learn.microsoft.com/en-us/azure/application-insights/app-insights-asp-net-exceptions.
If you use NLog, log4Net or System.Diagnostics.Trace for diagnostic tracing in your ASP.NET application, you can have your logs sent to Azure Application Insights, where you can explore and search them. Your logs will be merged with the other telemetry coming from your application, so that you can identify the traces associated with servicing each user request, and correlate them with other events and exception reports. You may refer this article: https://learn.microsoft.com/en-us/azure/application-insights/app-insights-asp-net-trace-logs.
I am setting up an ASP.NET WebApi application running on the Azure web application environment. Most of my controllers and endpoints work fine, but there are about 10 routes that return 500 errors "An error has occured". It's not random. It's the same routes every time and I can find no pattern (not all the HTTP methods, from different controllers where other routes in that same controller work fine, and so forth)
When these errors occur, no error logging gets triggered as far as I can tell in the app. (I am using Raygun.IO if that matters). I tried adding a global.asax file with following lines in the Application_Error function:
Exception ex = Server.GetLastError();
new RaygunClient().SendInBackground(null, ex);
but as far as I can see, it doesn't get triggered when these 500 errors occur. The only thing I have found in the Azure server logs is the following warning in the Failed Requests log:
However, I don't see any errors in the trace previous to that point. I'm also not finding any other errors in any of my Azure logs that I can relate to these failing routes.
It's .NET 4.6 (tried 4.5.1 and 4.5.2 with no difference) WebApi using an OWIN startup class. Also tried updating all my packages to no effect.
Check to be sure you don't have routes that conflict. When a URI matches two or more controller actions, and thus Web API can't pick one, you will get a 500 error.
If you have a consistent repro, then you can use remote debugging to attach to your web app and debug it (https://azure.microsoft.com/en-us/documentation/articles/web-sites-dotnet-troubleshoot-visual-studio/). If you can repro it through the browser, you can also turn the custom errors page off so that it shows the stack trace through the browser (<customErrors mode="off"/> under <server.web>).
Also, you can enable better diagnostic logs using the web app settings. Information on how to do so is here: https://azure.microsoft.com/en-us/documentation/articles/web-sites-configure/ under the section "Enabling diagnostic logs".
Also, as Brent said, URL conflicts can cause some nasty errors which aren't immediately obvious.
I figured out what was going on. There were actual errors occurring (mostly SQL related), but the way that we had configured the functions and error logging in those functions, the actual errors were being swallowed up and lost, overriding the error logging behavior of Raygun. I went through and ripped out the Try/Catch blocks we were using for error trapping and logging and the real errors finally emerged into the Raygun dashboard.
I'm trying to figure out why I'm getting 500 errors in setting up a website in IIS.
So far I've tried the following steps:
Enabled Failed Request Tracing (Doesn't write logs for this site, but
works for other sites)
Enabled detailed error messages. Still Getting the default 500 page
with no additional information.
Give app pool full permission to the project directory.
Made sure app pool was running on classic .NET 2 (old app)
Running the site under a permutation of (Classic/Integrated, .NET
2/4)
Enabled anonymous authentication
So my thinking is, somehow, the site fails before the logging modules are ran.
I suspect this is the case because I see no new entities in Event Viewer, IIS Advanced Logs folder, Or in Failed Request Tracing folder. My only source of information (besides 500 error) is a new entry in the IIS log:
2012-12-04 13:06:05 127.0.0.7 GET / - 80 - 127.0.0.1 Mozilla/5.0+(compatible;.....)
To verify this, is there a way to check which stage of the pipeline a request failed? Is it possible to run the logging modules before the failure occurs?
There is a trace event logger for HTTP.sys. With this you can determine if the request is even making it to the right app pool in IIS. Direction on usage
As a last resort, Microsoft offers a tool called Debug Diagnostic. When you have no other option, use this. It will produce a crash dump of the app pool of your choice. Not easy to go through, but it’s a lead. Direction on usage
I've got an Azure app up and running, but various requests generate a 500 error. There are no other details that come back from the server to let me know exactly what the problem is. No stack trace, no error message. The only thing I get back from the server are the http headers indicating I've got an error.
I've done a little looking around but can't seem to find a way to retrieve the error details that I'm looking for. I've seen some articles that suggest that I enable logging, but I'm not sure 1) how to do that, 2) where those log files would go and 3) how to access said log files. I've seen posts that say to add a whole bunch of code to my application to enable logging, but all I'm looking for is an error message and a stack trace from a 500 error. Do I really have to add a bunch of code to my app to see that information? If not, how can I get at it?
Thanks!
Chris
The best long-term solution is to enable Azure Diagnostics, which I think is what you're referring to. If you want a quick-and-dirty solution, you can log errors out to a file and then RDP into the role instances to view them. This is very similar to what you would do on a server in your own datacenter.
You can create the logs however you like. I've used log4net and RollingFileAppenders with some success. Setting the logfile path to something like "\logs\mylog.txt" will place the logs in the E: drive of the VM. Note you'll still need code somewhere in your app to capture the error and write it to the log - typically the global error handler in Global.asax is a good place for that.
You'll also have to enable RDP access to your role instances. There are many articles detailing how to do that. Here's one.
This is not a generally recommended approach because the logs may disappears when the role recycles or is recreated. It's also a pain in the butt to log to keep an eye on all those different servers.
One other warning - it's possible that the 500 error is due to some failure in your web.config. If that is the case, all the the application-level error logging in the world isn't going to help you. So be sure that your web.config is valid, and also check the Windows Event Logs while you're RDP'd into the server.
500 internal server error is most generally caused by some problem on the server when it was not able to understand incoming requests or there was some problem in configuration. So, try to run the app locally and see if there is some problem. You can record errors in a database in catches/application_error and also can use tracing. Believe me they are very helpful and worth a few extra lines of code.
For tracing have a look here, http://msdn.microsoft.com/en-us/magazine/ff714589.aspx
I use JavaScript to post an Asynchronous Request to a Web Service. This works about 95% of the time. Sometimes, the request fails to be processed.
Below is the error message in the Trace file of IIS:
2009-02-24 06:14:40 W3SVC861612620
10.248.24.20 POST /TestWebService /TestWebService.asmx - 3112 -
10.250.201.45 Mozilla/4.0+ (compatible;+MSIE+6.0;+MS+Web+Services+Client+Protocol+1.1.4322.2032)
500 0 0 1148 954 124876
This shows that the internal Error 500 has occurred to the request. Is there any way that I can get to know this in the JavaScript where i have posted the request from? Any workarounds are also fine.
Since you don't provide information about your javascript library, this will be hard to troubleshoot. However, if you're running on IIS 7, you can enable Failed Request Tracing.
Troubleshooting the old school way: your web method is generating an error 5% of the time, meaning it works in certain cases but fails in others. This is likely caused by the parameters sent to your web method. Even if you're unable to trap any runtime requests to your webmethod, you can inspect your logic to see what parameter conditions would cause a failure. Better yet, build a battery of unit tests to call your web method, passing every possible combination of parameters that is feasible.