调用 ApiController 会导致 SignalR 停止工作

Question

我有一个使用 SignalR (2.2.1) 和 Azure 移动应用进行身份验证的监控/日志记录中心。无论 ApiController 上是否存在 MobileAppController 属性，即使 ApiController 不包含集线器调用代码，从浏览器调用 /api/values 也会立即终止我的 SignalR 集线器。我必须重新启动网络应用程序才能让它再次工作。同时，网页将继续尝试连接/重新连接。

条带化的控制器看起来像

public class ValuesController : ApiController
{
    // GET api/values
    public string Get()
    {
        return "Hello World!";
    }
}

我在里面设置了WebApi

    public static void ConfigureMobileApp(IAppBuilder app, IDependencyResolver resolver)
    {
        HttpConfiguration config = new HttpConfiguration();
        config.DependencyResolver = resolver;
        config.IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Always;
        config.Formatters.Add(new BsonMediaTypeFormatter());

        new MobileAppConfiguration()
            //.MapApiControllers()
            .AddTables(
                new MobileAppTableConfiguration()
                    .MapTableControllers()
                    .AddEntityFramework()
            )
            .AddPushNotifications()
            .MapLegacyCrossDomainController()
            .ApplyTo(config);

        // Use Entity Framework Code First to create database tables based on your DbContext
        Database.SetInitializer(new MobileServiceInitializer());

        MobileAppSettingsDictionary settings = config.GetMobileAppSettingsProvider().GetMobileAppSettings();

        if (string.IsNullOrEmpty(settings.HostName))
        {
            app.UseAppServiceAuthentication(new AppServiceAuthenticationOptions
            {
                // This middleware is intended to be used locally for debugging. By default, HostName will
                // only have a value when running in an App Service application.
                SigningKey = ConfigurationManager.AppSettings["SigningKey"],
                ValidAudiences = new[] { ConfigurationManager.AppSettings["ValidAudience"] },
                ValidIssuers = new[] { ConfigurationManager.AppSettings["ValidIssuer"] },
                TokenHandler = config.GetAppServiceTokenHandler()
            });
        }

        config.Routes.MapHttpRoute(
              name: "DefaultApi",
              routeTemplate: "api/{controller}/{id}",
              defaults: new { id = RouteParameter.Optional }
          );
        app.UseWebApi(config);
    }

SignalR 设置使用

    public static void ConfigureSignalR(IAppBuilder app, CustomNinjectDependencyResolver resolver)
    {           
        IKernel kernel = resolver.Kernel;
        var connectionManager = resolver.Resolve<IConnectionManager>();
        var heartbeat = resolver.Resolve<ITransportHeartbeat>();
        var hubPipeline = resolver.Resolve<IHubPipeline>();

        kernel.Bind<IConnectionManager>().ToConstant(connectionManager);
        kernel.Bind<IUserIdProvider>().To<ZumoUserIdProvider>().InSingletonScope();

        var hubConfig = new HubConfiguration
        {
            Resolver = resolver,
            EnableDetailedErrors = true,
            EnableJSONP = true,
        };

        hubPipeline.AddModule(kernel.Get<LoggingHubPipelineModule>());

        app.MapSignalR(hubConfig);
    }

当我尝试转到 /api/values 时，会发生这种情况

Microsoft.Azure.AppService.Authentication Verbose: 0 : Received request: GET https://kamelos-app.azurewebsites.net/api/values
Microsoft.Azure.AppService.Authentication Verbose: 0 : Found 'AppServiceAuthSession' cookie for site 'xxx.azurewebsites.net'. Length: 768.
Microsoft.Azure.AppService.Authentication Verbose: 0 : Authenticated xxx successfully using 'Session Cookie' authentication.
Exception thrown: 'System.Reflection.ReflectionTypeLoadException' in mscorlib.dll
Exception thrown: 'System.Net.WebSockets.WebSocketException' in System.Web.dll
Exception thrown: 'System.Net.WebSockets.WebSocketException' in mscorlib.dll
Exception thrown: 'System.OperationCanceledException' in mscorlib.dll
Exception thrown: 'System.OperationCanceledException' in System.Web.dll
Microsoft.Azure.AppService.Authentication Verbose: 0 : Received request: GET https://kamelos-app.azurewebsites.net/favicon.ico
Microsoft.Azure.AppService.Authentication Verbose: 0 : Exception thrown: 'System.OperationCanceledException' in mscorlib.dll
Found 'AppServiceAuthSession' cookie for site 'kamelos-app.azurewebsites.net'. Length: 768.
Exception thrown: 'System.OperationCanceledException' in mscorlib.dll
Microsoft.Azure.AppService.Authentication Verbose: 0 : Authenticated xxx successfully using 'Session Cookie' authentication.
Exception thrown: 'System.OperationCanceledException' in mscorlib.dll

尝试将 SignalR 降级到 2.1.2 无济于事。同样的问题。

更新。如果 SignalR 会话未在进行中，并且我转到 /api/values，则输出日志中有 WebSocketException，但是，之后转到监控页面，那里不再是 SignalR。至于监控代码：

<script type="text/javascript">
    $(function () {
        function encodeHtml(html) {
            // html still emits double quotes so we need to replace these entities to use them in attributes.
            return $("<div/>").text(html).html().replace(/\"/g, "&quot;");
        }
        var monitor = $.connection.monitor;
        $.connection.hub.logging = true;
        monitor.client.logError = function (value) {
            $('#logs').prepend('<li class="error">' + encodeHtml(value).replace('\n', '<br/>') + '</li>');
        };
        monitor.client.logWarn = function (value) {
            $('#logs').prepend('<li class="warn">' + encodeHtml(value).replace('\n', '<br/>') + '</li>');
        };
        monitor.client.logMessage = function (value) {
            $('#logs').prepend('<li class="message">' + encodeHtml(value).replace('\n', '<br/>') + '</li>');
        };
        $.connection.hub.disconnected(function () {
            setTimeout(function () {
                $.connection.hub.start();
            }, 5000);
        });
        $.connection.hub.start();
    });
</script>

但这在调用 /api/values 之前有效。所以我不认为是因为监控代码。此外，当 SignalR 失败时，整个服务器都会失败。从不同的 IP 地址进来也无法从 SignalR 获得信号。

如果监控页面没有起来，那么我看到了

Microsoft.Azure.AppService.Authentication Verbose: 0 : Received request: GET https://kamelos-app.azurewebsites.net/api/values
Microsoft.Azure.AppService.Authentication Verbose: 0 : Found 'AppServiceAuthSession' cookie for site 'xxx.azurewebsites.net'. Length: 768.
Microsoft.Azure.AppService.Authentication Verbose: 0 : Authenticated Tim Uy successfully using 'Session Cookie' authentication.
Exception thrown: 'System.Reflection.ReflectionTypeLoadException' in mscorlib.dll
'w3wp.exe' (CLR v4.0.30319: /LM/W3SVC/1848204182/ROOT-2-131345909532020945): Loaded 'D:\Windows\Microsoft.Net\assembly\GAC_MSIL\Microsoft.Data.Services.Client\v4.0_5.6.2.0__31bf3856ad364e35\Microsoft.Data.Services.Client.dll'. Cannot find or open the PDB file.
05:32:22.128 [25] DEBUG  ValuesController - requested /api/values

更新 2。 问题是config.DependencyResolver = resolver。当这被注释掉时，SignalR 不会崩溃。我认为以某种方式运行 apiController 会导致解析器被转储。

是的，ApiController 完成的那一刻，我的 CustomNinjectDependencyResolver 就被释放了。为什么会这样？

Answer 1

原来有问题的行是

config.DependencyResolver = resolver

并且 WebApi 在 ApiController 被调用后处理解析器。见Why is ASP.NET Web Api's Dependency Resolver being disposed?

"Web API 每次请求都会调用 BeginScope() 方法一次 基础设施和 Web API 将调用 IDependencyScope.Dispose() 时 请求结束。”