Diagnose errors and exceptions with Azure Application Insights - Azure Monitor (2023)

Exceptions in web applications can be reported withApp Insights. You can associate failed requests with exceptions and other events on the client and server, allowing you to quickly diagnose root causes. In this article, you'll learn how to set up exception reporting, explicitly report exceptions, diagnose errors, and more.

Set up exception reports

You can set Application Insights to report on exceptions that occur on the server or client. Depending on the platform your app depends on, you'll need the appropriate extension or SDK.

server side

For your server-side application to report exceptions, consider the following scenarios:

• addApplication Insights extensionza Azure Web Apps.
• addApplication monitoring extensionza Azure Virtual Machines i Azure Virtual Machine Scale Sets IIS hostirane aplikacije.
• InstallApplication Insights SDKIn the application code, run:Application Insights-Agentfor the IIS web server or enable themJava agentfor Java web applications.

buyer's side

The JavaScript SDK provides client-side reporting of exceptions that occur in web browsers. For information about setting up exception reporting on the client, seeInsights into web applications.

application frameworks

Some application frameworks require more configuration. Consider the following technologies:

• web formula
• MVC
• Web-API 1.*
• Web-API 2.*
• WCF

Diagnose exceptions using Visual Studio

Open the application solution in Visual Studio. Run the application either on your server or on your development machine usingF5. Recreate the exception.

open itApplication Insights-SucheTelemetry window in Visual Studio. Select an option when debuggingApp Insightsdrop down field.

Select an exception report to view its stack trace. To open the corresponding code file, select the line reference in the stack trace.

If CodeLens is enabled, the exception information is displayed:

Diagnose errors using the Azure portal

Application Insights provides a curated application performance management experience that helps you diagnose failures in your monitored applications. First in the Application Insights resource menu on the left belowInvestigation, choosefailurePossibility.

You can see error rate trends for your requests, how many fail, and how many users are affected. TheIn totalThe display shows some of the most useful distributions specific to the selected failed operation. You'll see the three most common response codes, the three most common exception types, and the three most common failed dependency types.

To view representative samples for each of these subsets of operations, select the associated link. For example, to diagnose exceptions, you can select the number of a specific exception to display withDetails of end-to-end transactionstab.

Instead of looking at the exceptions of a particular failed operation, you can start with thatIn totalSee exceptions by switching toexceptionstab above. Here you can see all exceptions logged for your monitored application.

Custom tracking and log data

To get diagnostic data specific to your application, you can include code to send your own telemetry. Your custom telemetry or log data will appear in the diagnostic search along with the request, page view, and other automatically collected data.

UseMicrosoft.VisualStudio.ApplicationInsights.TelemetryClientSeveral APIs are available to you:

• TelemetryClient.TrackEventit's usually used to track usage patterns, but the data it sends is also shown belowCustom eventswhen looking for a diagnosis. Events are named and can contain string properties and numeric metrics that you can useFilter your diagnostic searches.
• TelemetryClient.TrackTraceallows sending longer data such as POST information.
• TelemetryClient.TrackExceptionsends exception details eg B. Stack traces, to Application Insights.

To view these events, open the menu on the leftLook for. Select the drop-down menuevent types, and then selectCustom event,Persecute, orException.

See Request for POST data

Request details do not include data sent to your application in a POST call. To report this information:

• Install the SDKin your application project.
• Paste the invitation code into your applicationMicrosoft.ApplicationInsights.TrackTrace(). Send the POST data in the message parameter. Since the allowed size is limited, try to send only essential data.
• If you investigate the failed request, you will find its traces.

Record exceptions and associated diagnostic data

First of all, the portal doesn't show you all the exceptions that lead to errors in your application. If you are using a browser, you will be shown all browser exceptionsJavaScript-SDKon your web pages. However, most server exceptions are caught by IIS and you have to write a bit of code to see them.

You can:

• Explicitly note exceptionsby injecting code into exception handlers to report exceptions.
• Automatically catch exceptionsby configuring your ASP.NET framework. Required accessories vary depending on the type of frame.

Report exceptions explicitly

The easiest way to apply is to turn on the call totrackException()in the exception handler.

pokušaj{ // ...}catch (ex){ appInsights.trackException(ex, "handler loc", { Game: currentGame.Name, State: currentGame.State.ToString() });}

var telemetry = new TelemetryClient();try{ // ...}catch (Exception ex){ var Properties = new Dictionary{ ["Game"] = currentGame.Name }; varmeasurements = new Dictionary{ ["Korisnici"] = currentGame.Users.Count }; // Ausnahmetelemetrie senden: telemetry.TrackException(ex, Properties,measurements);}

Dim telemetry = New TelemetryClientTry ' ...Catch ex as Exception ' Richten Sie einige Eigenschaften ein: Dim Properties = New Dictionary (Of String, String) Properties.Add("Game", currentGame.Name) Dimmeasurements = New Dictionary (Of String) , Double)measurements.Add("Users", currentGame.Users.Count) 'Senden Sie die Ausnahmetelemetrie: telemetry.TrackException(ex, Properties,measurements)End Try

The "Properties" and "Measurements" parameters are optional, but useful forFilter and addAdditional information. For example, if you have an application that can run multiple games, you can find all exception reports related to a specific game. You can add as many items as you want to each dictionary.

Browser exceptions

Most browser exceptions are reported.

If your website contains script files from content delivery networks or other domains, make sure the script tag has an attributecrossorigin="anonymous"and which the server sendsCORS-Header. This behavior allows you to obtain stack traces and details about unhandled JavaScript exceptions from these resources.

Reuse your telemetry client

SDependency Injection (DI) u .NET, the appropriate .NET SDK, and the correct configuration of Application Insights for DI, you can request itTelemetryClientas a constructor parameter.

javna klasa ExampleController: ApiController{ private readonly TelemetryClient _telemetryClient; public ExampleController(TelemetryClient telemetryClient) { _telemetryClient = telemetryClient; }}

In the previous example,TelemetryClientis injectedExampleControllerClass.

web formula

For web forms, the HTTP engine can catch exceptions if no redirects are configuredCustom errors. However, if you have active redirects, add the following linesapplication errorfunction inGlobal.asax.cs.

void Application_Error(object sender, EventArgs e){ if (HttpContext.Current.IsCustomErrorEnabled && Server.GetLastError () != null) { _telemetryClient.TrackException(Server.GetLastError()); }}

In the previous example,_telemetryClientis a class variable of typeTelemetryClient.

MVC

Starting with Application Insights Web SDK version 2.6 (Beta 3 and later), Application Insights automatically catches unhandled exceptions thrown in MVC 5+ controller methods. If you have previously added a custom handler to catch such exceptions, you can remove it to prevent duplicate exception handling.

There are several scenarios where the exception filter may not properly handle errors when throwing exceptions:

• Controller designers
• From the message handler
• Beim Routing
• During serialization of response content
• When starting the application
• For background tasks

All exceptionsnamireniafter application it must still be monitored manually. Unhandled exceptions originating from the controller typically result in a 500 "Internal Server Error" response. If such a response is manually constructed as a result of a handled exception or no exception, it will be tracked in the appropriate request telemetryresult code500. However, the Application Insights SDK cannot trace the corresponding exception.

Support for previous versions

If you are using MVC 4 (and earlier) from Application Insights Web SDK 2.5 (and earlier), see the following examples for exception tracking.

Such asCustom errorsconfiguration isFrom, Exceptions will be available forHTTP-modulcollect. However, if it isOnly at a distance(default) orAn, the exception is thrown and is not available for automatic collection by Application Insights. You can fix this behavior by overriding itKlasa System.Web.Mvc.HandleErrorAttributeand applying an overridden class as shown here for different MVC versions (seeGitHub-Quelle):

using System;using System.Web.Mvc;using Microsoft.ApplicationInsights;namespace MVC2App.Controllers{ [AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, Inherited = true, AllowMultiple = true)] public class AiHandleErrorAttribute : HandleErrorAttribute { public override void OnException (ExceptionContext filterContext) { if (filterContext != null && filterContext.HttpContext != null && filterContext.Exception != null) { //The attribute should only track exceptions if CustomErrors is set to On. //If CustomErrors is set to Off, exceptions will occur. Catches the AI ​​HTTP module if (filterContext.HttpContext.IsCustomErrorEnabled) { //Or reuse the instance (recommended!). See note above. var ai = new TelemetryClient(); ai.TrackException(filterContext.Exception); } } base.OnException(filterContext); } }}

MVC 2

Replace the HandleError attribute with your new attribute in your controllers:

namespace MVC2App.Controllers { [AiHandleError] public class HomeController : Controller { // omitted for brevity } }

In the end

MVC 3

to registerAiHandleErrorAttributeas a global filter inGlobal.asax.cs:

javna klasa MyMvcApplication: System.Web.HttpApplication{ public static void RegisterGlobalFilters(GlobalFilterCollection filter) { filter.Add(new AiHandleErrorAttribute()); }}

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MVC 4, MVC 5

to registerAiHandleErrorAttributeas a global filter inFilterConfig.cs:

public class FilterConfig{ public static void RegisterGlobalFilters(GlobalFilterCollection filter) { // Default value replaced by override to handle unhandled exceptions filter.Add(new AiHandleErrorAttribute()); }}

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Web-API

Starting with Application Insights Web SDK version 2.6 (Beta 3 and later), Application Insights automatically catches unhandled exceptions thrown in controller methods for Web API 2+. If you have previously added a custom handler to catch such exceptions, as described in the following examples, you can remove it to prevent exceptions from being caught twice.

There are several cases that exception filters cannot handle. For example:

• Exceptions thrown by controller constructors.
• Exceptions thrown by message handlers.
• Exceptions that occur during routing.
• Exceptions thrown while serializing response content.
• An exception is raised when the application is launched.
• Background tasks throw an exception.

All exceptionsnamireniafter application it must still be monitored manually. Unhandled exceptions originating from the controller typically result in a 500 "Internal Server Error" response. If such a response is manually constructed due to a handled exception or due to the absence of an exception, it will be tracked in the appropriate request telemetryresult code500. However, the Application Insights SDK cannot trace the corresponding exception.

Support for previous versions

If you are using Application Insights Web SDK 2.5 (and earlier) Web API 1 (and earlier), see the following examples for exception tracing.

Web-API 1.x

overwriteSystem.Web.Http.Filters.ExceptionFilterAttribute:

using System.Web.Http.Filters;using Microsoft.ApplicationInsights;namespace WebAPI.App_Start{ public class AiExceptionFilterAttribute : ExceptionFilterAttribute { public override void OnException(HttpActionExecutedContext actionExecutedContext) { if (actionExecutedContext != null && actionExecutedContext. Iznimka != null) { / /Oder Instanz wiederverwenden (empfohlen!). Siehe Hinweis oben. var ai = new TelemetryClient(); ai.TrackException(actionExecutedContext.Exception); } base.OnException(actionExecutedContext); } }}

You can add this overridden attribute to specific controllers or add it to the global filter configuration in theWebApiConfigClass:

using System.Web.Http;using WebApi1.x.App_Start;namespace WebApi1.x{ public static class WebApiConfig { public static void Register(HttpConfiguration config) { config.Routes.MapHttpRoute( name: "DefaultApi", routeTemplate: "api/ {kontroler}/{id}", Standardwerte: new { id = RouteParameter.Optional }); // ... config.EnableSystemDiagnosticsTracing(); // Prikaz podataka za Application Insights erfassen: config.Filters.Add(new AiExceptionFilterAttribute()); } }}

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Web-API 2.x

Add an implementationIExceptionLogger:

using System.Web.Http.ExceptionHandling;using Microsoft.ApplicationInsights;namespace ProductsAppPureWebAPI.App_Start{ public class AiExceptionLogger : ExceptionLogger { public override void Log(ExceptionLoggerContext context) { if (context != null && context.Exception != null) { / /ili ponovno upotrijebite instancu (preporučeno!). vidi napomenu iznad var ai = new TelemetryClient(); ai.TrackException(context.Exception); } base.Log(kontekst); } }}

Add this snippet to services inWebApiConfig:

using System.Web.Http;using System.Web.Http.ExceptionHandling;using ProductsAppPureWebAPI.App_Start;namespace WebApi2WithMVC{ public static class WebApiConfig { public static void Register(HttpConfiguration config) { // Web-API-Konfiguration und -Dienste // Web-API-Routen config.MapHttpAttributeRoutes(); config.Routes.MapHttpRoute( name: "DefaultApi", routeTemplate: "api/{controller}/{id}", defaults: new { id = RouteParameter.Optional }); config.Services.Add(typeof(IExceptionLogger), new AiExceptionLogger()); } }}

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As an alternative, you can:

• Replace the only oneexception handlerAn instance with a custom implementationIExceptionHandler. This exception handler is only called when the framework can still choose which response message to send, not for example when the connection is terminated.
• Use exception filters as described in the previous section on Web API 1.x controllers, which are not called in all cases.

WCF

Add a class to be extendedAttributeand carried outIErrorHandlerIIServiceBehavior.

korištenje sustava; sa System.Collections.Generic; sa System.Linq; using System.ServiceModel.Description; sa System.ServiceModel.Dispatcher; sa System.Web; Korištenje Microsoft.ApplicationInsights; namespace WcfService4.ErrorHandling { public class AiLogExceptionAttribute: Attribute, IErrorHandler, IServiceBehavior { public void AddBindingParameters(ServiceDescription serviceDescription, System.ServiceModel.ServiceHostBase serviceHostBase, System.Collections.ObjectModel.Collectionkrajnje točke, System.ServiceModel.Channels.BindingParameterCollection bindingParameters) { } public void ApplyDispatchBehavior(ServiceDescription serviceDescription, System.ServiceModel.ServiceHostBase serviceHostBase) { foreach (ChannelDispatcher disp in serviceHostBase.ChannelDispatchers) { disp.Error Rukovatelji.Dodaj(ovo); } } public void Validate(ServiceDescription serviceDescription, System.ServiceModel.ServiceHostBase serviceHostBase) { } bool IErrorHandler.HandleError(Exception error) { //ili ponovno upotrijebi instancu (preporučeno!). vidi napomenu iznad var ai = new TelemetryClient(); ai.TrackException(greška); vratiti lažno; } void IErrorHandler.ProvideFault(greška izuzetka, verzija System.ServiceModel.Channels.MessageVersion, Ref. System.ServiceModel.Channels.Message error) { } } }

Add an attribute to service implementations:

namespace WcfService4{ [AiLogException] public class Service1 : IService1 { // omitted for brevity }}

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Exception counters

Ako yesinstalirao Azure Monitor Application Insights AgentYou can get a graph of the exception rate measured by .NET on your server. Both handled and unhandled .NET exceptions are included.

Open the Metric Explorer tab and add a new chart. Under, underperformance indicators, chooseexceptional rate.

The .NET Framework calculates the rate by counting the number of exceptions in an interval and dividing by the length of the interval.

This number is different from the number of exceptions calculated by the Application Insights portal countTrackExceptionreports. The sampling intervals are different and the SDK is not broadcastingTrackExceptionReports for all handled and unhandled exceptions.

Next steps

• Track REST, SQL, and other dependency calls
• Track page load times, browser exceptions, and AJAX calls
• Monitor performance counters