.net - 使用 ETW 记录异常的最佳方法是什么？

Question

是否有使用 ETW 记录异常的标准方法？

据我所知，唯一的方法是记录消息和可能的内部异常消息，因为异常类型没有强类型参数。

Answer 1

所有 CLR 异常（第一次机会，以及可能最终导致应用程序崩溃的异常）都由 CLR 运行时提供程序在启用时记录到 ETW。

这是一个带有调用堆栈的完全“结构化”事件（如果你想要的话）。实际上，您可以使用 TraceEvent NuGet 包（Install-Package Microsoft.Diagnostics.Tracing.TraceEvent）编写监控应用程序

我正在粘贴我经常使用的监控代码。将它放在控制台应用程序中，调用 Run 方法，并从任何进程中抛出一些托管异常，它将打印信息及其调用堆栈。

注意：您需要引用的 NuGet 包，然后引用其程序集，然后此代码将编译。

class TraceLogMonitor
{
    static TextWriter Out = AllSamples.Out;

    public static void Run()
    {
        var monitoringTimeSec = 10;
       TraceEventSession session = null;

        Console.CancelKeyPress += (object sender, ConsoleCancelEventArgs cancelArgs) =>
        {
            if (session != null)
                session.Dispose();
            cancelArgs.Cancel = true;
        };

        var exceptionGeneationTask = Task.Factory.StartNew(delegate
        {
            Thread.Sleep(3000);
            ThrowException();
        });

        Timer timer = null;

        using (session = new TraceEventSession("TraceLogSession"))
        {
            Out.WriteLine("Enabling Image load, Process and Thread events.  These are needed to look up native method names.");
            session.EnableKernelProvider(

                KernelTraceEventParser.Keywords.ImageLoad |
                KernelTraceEventParser.Keywords.Process,  
                KernelTraceEventParser.Keywords.None
                );

            Out.WriteLine("Enabling CLR Exception and Load events (and stack for those events)");

            session.EnableProvider(
                ClrTraceEventParser.ProviderGuid,
                TraceEventLevel.Informational,
                (ulong)(ClrTraceEventParser.Keywords.Jit |              
                ClrTraceEventParser.Keywords.JittedMethodILToNativeMap |
                ClrTraceEventParser.Keywords.Loader |                   
                ClrTraceEventParser.Keywords.Exception |               
                ClrTraceEventParser.Keywords.Stack));                   

            Out.WriteLine("Enabling CLR Events to 'catch up' on JIT compiled code in running processes.");
            session.EnableProvider(ClrRundownTraceEventParser.ProviderGuid, TraceEventLevel.Informational,
                (ulong)(ClrTraceEventParser.Keywords.Jit |          
                ClrTraceEventParser.Keywords.JittedMethodILToNativeMap | 
                ClrTraceEventParser.Keywords.Loader |               
                ClrTraceEventParser.Keywords.StartEnumeration));    

            TextWriter SymbolLookupMessages = new StringWriter();

            var symbolPath = new SymbolPath(SymbolPath.SymbolPathFromEnvironment).Add(SymbolPath.MicrosoftSymbolServerPath);
            SymbolReader symbolReader = new SymbolReader(SymbolLookupMessages, symbolPath.ToString());

            Out.WriteLine("Open a real time TraceLog session (which understands how to decode stacks).");
            using (TraceLogEventSource traceLogSource = TraceLog.CreateFromTraceEventSession(session)) 
            {
                Action<TraceEvent> PrintEvent = ((TraceEvent data) => Print(data, symbolReader));

                traceLogSource.Clr.ExceptionStart += PrintEvent;
                traceLogSource.Clr.LoaderModuleLoad += PrintEvent;

                traceLogSource.Kernel.PerfInfoSample += ((SampledProfileTraceData data) => Print(data, symbolReader));

                Out.WriteLine("Waiting {0} sec for Events.  Run managed code to see data. ", monitoringTimeSec);
                Out.WriteLine("Keep in mind there is a several second buffering delay");

                timer = new Timer(delegate(object state)
                {
                    Out.WriteLine("Stopped Monitoring after {0} sec", monitoringTimeSec);
                    if (session != null)
                        session.Dispose();
                    session = null;
                }, null, monitoringTimeSec * 1000, Timeout.Infinite);

                traceLogSource.Process();
            }
        }
        Out.WriteLine("Finished");
        if (timer != null)
            timer.Dispose();
    }

    static void Print(TraceEvent data, SymbolReader symbolReader)
    {
        if (data.Opcode == TraceEventOpcode.DataCollectionStart)
            return;

        if (data is ExceptionTraceData && ((ExceptionTraceData) data).ExceptionType.Length == 0)
            return;

        Out.WriteLine("EVENT: {0}", data.ToString());
        var callStack = data.CallStack();
        if (callStack != null)
        {
            ResolveNativeCode(callStack, symbolReader);
            Out.WriteLine("CALLSTACK: {0}", callStack.ToString());
        }
    }

    static private void ResolveNativeCode(TraceCallStack callStack, SymbolReader symbolReader)
    {
        while (callStack != null)
        {
            var codeAddress = callStack.CodeAddress;
            if (codeAddress.Method == null)
            {
                var moduleFile = codeAddress.ModuleFile;
                if (moduleFile == null)
                    Trace.WriteLine(string.Format("Could not find module for Address 0x{0:x}", codeAddress.Address));
                else
                    codeAddress.CodeAddresses.LookupSymbolsForModule(symbolReader, moduleFile);
            }
            callStack = callStack.Caller;
        }
    }

    [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining)]
    private static void ThrowException()
    {
        ThrowException1();
    }

    [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining)]
    private static void ThrowException1()
    {
        Out.WriteLine("Causing an exception to happen so a CLR Exception Start event will be generated.");
        try
        {
            throw new Exception("This is a test exception thrown to generate a CLR event");
        }
        catch (Exception) { }
    }
}

Answer 2

使用额外的事件并在 catch 块中触发此事件并将异常消息作为参数传递给事件

[Event(1, Message = "Application Falure: {0}", Level = EventLevel.Error, Keywords = Keywords.Diagnostic)]
public void Failure(string message) 
{ 
    if (this.IsEnabled())
    {
        this.WriteEvent(1, message); 
    }
}

使用级别和关键字来控制是否要一直记录它。

Answer 3

ETW 不是 .NET 特定的，因此不会有任何强类型的 .NET 特定 API 来记录 .NET 异常。相反，您将创建自己的强类型 API。这就是语义记录和语义记录应用程序块背后的想法。