本文主要讲解使用ZipKin构建NetCore分布式链路跟踪

场景

因为最近公司业务量增加，而项目也需要增大部署数量，K8S中Pod基本都扩容了一倍，新增了若干物理机，部分物理机网络通信存在问题，导致部分请求打入有问题的物理机时总会出现超时的情况，由于之前系统中没有使用链路跟踪，导致排查问题比较慢，所以就去研究了市面上的链路框架，结果发现了ZipKin这款比较轻量级的链路跟踪框架。

实例代码

本文日志系统采用Exceplesstion
示例代码请求链路为SimpleZipkin(网关服务)--->WebApi(Api服务)--->OrderApi(订单服务)
首先创建公用类库，引用以下包(本文以1.5.0版本为例)
如果部署Zipkin使用的是Mysql作为存储，切记Mysql版本不要高于8.0,Zipkin暂不支持8.0的版本

zipkin4net
zipkin4net.middleware.aspnetcore

创建ZipKin帮助类

public static class ZipKinExtensions{public static IServiceCollection AddZipKin(this IServiceCollection services){return services.AddSingleton<HttpDiagnosticSourceObserver >();}public static IApplicationBuilder UseZipKin(this IApplicationBuilder app, IHostApplicationLifetime lifetime, ILoggerFactory loggerFactory, string serviceName, string zipKinUrl){DiagnosticListener.AllListeners.Subscribe(app?.ApplicationServices?.GetService<TraceObserver>());lifetime.ApplicationStarted.Register(() =>{TraceManager.SamplingRate = 1.0f;//记录数据密度，1.0代表全部记录var logger = new TracingLogger(loggerFactory, "zipkin4net");var httpSender = new HttpZipkinSender(zipKinUrl, "application/json");var tracer = new ZipkinTracer(httpSender, new JSONSpanSerializer(), new Statistics());var consoleTracer = new zipkin4net.Tracers.ConsoleTracer();TraceManager.RegisterTracer(tracer);TraceManager.RegisterTracer(consoleTracer);TraceManager.Start(logger);});lifetime.ApplicationStopped.Register(() => TraceManager.Stop());app.UseTracing(serviceName);//这边的名字可自定义return app;}}

Exceptionless帮助类

/// <summary>/// 日志扩展类/// </summary>public static class LogHelper{/// <summary>/// 记录Info日志/// </summary>/// <param name="logger"></param>/// <param name="message"></param>public static void InformationToException(this ILogger logger, string message){var tranceId = Trace.Current?.CurrentSpan.TraceId.ToString("x16");logger.LogInformation($@"tranceId={tranceId}，日志主体为：{message}");}/// <summary>/// 记录Debug日志/// </summary>/// <param name="logger"></param>/// <param name="message"></param>public static void DebugToException(this ILogger logger, string message){var tranceId = Trace.Current?.CurrentSpan.TraceId.ToString("x16");logger.LogDebug($@"tranceId={tranceId}，日志主体为：{message}");}/// <summary>/// 记录错误日志/// </summary>/// <param name="logger"></param>/// <param name="message"></param>public static void ErrorToException(this ILogger logger, string message){var tranceId = Trace.Current?.CurrentSpan.TraceId.ToString("x16");logger.LogError($@"tranceId={tranceId}，日志主体为：{message}");}/// <summary>/// 记录追踪日志/// </summary>/// <param name="logger"></param>/// <param name="message"></param>public static void TraceToException(this ILogger logger, string message){var tranceId = Trace.Current?.CurrentSpan.TraceId.ToString("x16");logger.LogTrace($@"tranceId={tranceId}，日志主体为：{message}");}/// <summary>/// 记录警告日志/// </summary>/// <param name="logger"></param>/// <param name="message"></param>public static void WarningToException(this ILogger logger, string message){var tranceId = Trace.Current?.CurrentSpan.TraceId.ToString("x16");logger.LogWarning($@"tranceId={tranceId}，日志主体为：{message}");}}

接下来创建SimpleZipkin、WebApi、OrderApi等项目(因为结构一致，所以本文只创建一个)，首先引用Exceplesstion

public class Program{public static void Main(string[] args){CreateHostBuilder(args).Build().Run();}public static IHostBuilder CreateHostBuilder(string[] args) =>Host.CreateDefaultBuilder(args).ConfigureLogging((hostContext, configLogging) =>{configLogging.AddConfiguration(hostContext.Configuration.GetSection("Logging"));configLogging.AddConsole();configLogging.AddDebug();configLogging.AddExceptionless();ExceptionlessClient.Default.Configuration.SetDefaultMinLogLevel(Exceptionless.Logging.LogLevel.Debug);configLogging.SetMinimumLevel(LogLevel.Debug);                   }).ConfigureWebHostDefaults(webBuilder =>{webBuilder.UseStartup<Startup>();});}

接下来在Startup中引入ZipKin

public void ConfigureServices(IServiceCollection services){// 注入Rpc//AppContext.SetSwitch("System.Net.Http.SocketsHttpHandler.Http2UnencryptedSupport", true);//services.AddGrpcClient<HelloServer.HelloServerClient>((p, o) =>//{//    o.Address = new Uri("http://127.0.0.1:3848");//});//.AddHttpMessageHandler(provider => TracingHandler.WithoutInnerHandler("RpcService"));services.AddControllers();services.AddZipKin();services.AddSingleton<IDiagnosticSource, HttpDiagnosticSourceDemo>();services.AddHttpClient("webApi", client => { client.BaseAddress = new Uri($"http://localhost:5001"); });services.AddSwaggerGen(c =>{c.SwaggerDoc("v1", new OpenApiInfo { Title = "SimpleZipKin", Version = "v1" });});}public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ILoggerFactory loggerFactory,IHostApplicationLifetime lifetime){if (env.IsDevelopment()){app.UseDeveloperExceptionPage();app.UseSwagger();app.UseSwaggerUI(c => c.SwaggerEndpoint("/swagger/v1/swagger.json", "SimpleZipkin v1"));}Configuration.GetSection("ExceptionLess").Bind(ExceptionlessClient.Default.Configuration);ExceptionlessClient.Default.Configuration.SetDefaultMinLogLevel(Exceptionless.Logging.LogLevel.Debug);app.UseZipKin(lifetime, loggerFactory, "SimpleZip", "http://127.0.0.1:9411");//SimpleZip修改为对应的应用名称，127.0.0.1地址切换为自己的zipkin地址  app.UseRouting();app.UseAuthorization();app.UseEndpoints(endpoints => { endpoints.MapControllers(); });}

接下来创建对应的Controller

[Route("/api/Home")]public class HomeController : Controller{private readonly IHttpClientFactory _httpClientFactory;private readonly ILogger _logger;/// <summary>/// 构造函数/// </summary>/// <param name="httpClientFactory"></param>/// <param name="logger"></param>public HomeController(IHttpClientFactory httpClientFactory, ILogger<HomeController> logger){_httpClientFactory = httpClientFactory;//_helloServerClient = helloServerClient;_logger = logger;}[HttpGet("GetZipKin")]public async Task<string> GetZipKin(){_logger.InformationToException($@"这里是SimpleZipKinApi");var httpClient = _httpClientFactory.CreateClient("webApi");var httpResult = await httpClient.GetAsync($"api/order/getorder");var result = await httpResult.Content.ReadAsStringAsync();return result;}    }

最后在appsettings.json中加入对应的Exceplesstionless配置

"ExceptionLess": {"ApiKey": "****************************","ServerUrl": "http://127.0.0.1:5000"}

OrderApi、WebApi如法炮制，修改对应的请求链路信息

接下来我们使用DiagnosticAdapter做链路记载，在公共类库中创建HttpDiagnosticListener类
DiagnosticSource是Runtime层提供，应用层可以通过它与系统集成、事件日志、以及性能计数器进行交互。
DiagnosticSource官方介绍：https://docs.microsoft.com/zh-cn/dotnet/api/system.diagnostics.diagnosticsource?view=net-5.0
关于DiagnosticSource设计参考原有yi念之间大佬的文章：https://www.cnblogs.com/wucy/p/13532534.html

public class HttpDiagnosticSourceDemo : IDiagnosticSourceDemo{public string DiagnosticName => "HttpDiagnosticSourceDemo";private ClientTrace _clientTrace;private readonly IInjector<HttpHeaders> _injector = Propagations.B3String.Injector<HttpHeaders>((carrier, key, value) => carrier.Add(key, value));[DiagnosticName("System.Net.Http.Request")]public void HttpRequest(HttpRequestMessage request){_clientTrace = new ClientTrace("simpleZipKin", request.Method.Method);if (_clientTrace.Trace != null){_injector.Inject(_clientTrace.Trace.CurrentSpan, request.Headers);}}[DiagnosticName("System.Net.Http.Response")]public void HttpResponse(HttpResponseMessage response){if (_clientTrace.Trace != null){_clientTrace.AddAnnotation(Annotations.Tag(zipkinCoreConstants.HTTP_PATH, response.RequestMessage.RequestUri.LocalPath));_clientTrace.AddAnnotation(Annotations.Tag(zipkinCoreConstants.HTTP_METHOD, response.RequestMessage.Method.Method));_clientTrace.AddAnnotation(Annotations.Tag(zipkinCoreConstants.HTTP_HOST, response.RequestMessage.RequestUri.Host));if (!response.IsSuccessStatusCode){_clientTrace.AddAnnotation(Annotations.Tag(zipkinCoreConstants.HTTP_STATUS_CODE, ((int)response.StatusCode).ToString()));}}}[DiagnosticName("System.Net.Http.Exception")]public void HttpException(HttpRequestMessage request, Exception exception){}}

IDiagnosticSourceDemo接口信息如下：

public interface IDiagnosticSourceDemo{string DiagnosticName { get; }}

HttpDiagnosticSourceObserver方法如下：

public class HttpDiagnosticSourceObserver : IObserver<DiagnosticListener>{private IEnumerable<IDiagnosticSourceDemo> _diagnosticSourceDemo;public HttpDiagnosticSourceObserver (IEnumerable<IDiagnosticSourceDemo> diagnosticSourceDemo){_diagnosticSourceDemo= diagnosticSourceDemo;}public void OnCompleted(){}public void OnError(Exception error){}public void OnNext(DiagnosticListener listener){var diagnosticSource= _diagnosticSourceDemo.FirstOrDefault(i => i.DiagnosticName == listener.Name);if (traceDiagnostic != null){//适配订阅listener.SubscribeWithAdapter(diagnosticSource);}}}

最终运行结果如下：
Zipkin为：

Exceplesstion日志记录信息为

通过Exceptionless记录的环境信息也能将对应的机器定位

参考

本文引用文章连接如下：
DiagnosticSource官方介绍：https://docs.microsoft.com/zh-cn/dotnet/api/system.diagnostics.diagnosticsource?view=net-5.0
DiagnosticSource参考连接：https://www.cnblogs.com/wucy/p/13532534.html
                   https://sudonull.com/post/3671-Using-the-DiagnosticSource-in-NET-Core-Theory
                   https://andrewlock.net/logging-using-diagnosticsource-in-asp-net-core/
docker部署Zipkin：https://www.cnblogs.com/binz/p/12658020.html
docekr部署exceptionless：https://www.cnblogs.com/edisonchou/p/exceptionless_v5_deployment_introduction.html