remove cap.UseDashboard. It's will be automatically enabled by registerd services.

samples/Sample.RabbitMQ.PostgreSql/Startup.cs

@@ -4,10 +4,7 @@ using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
-using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Logging;
-using Microsoft.Extensions.Options;
 
 namespace Sample.RabbitMQ.PostgreSql
 {
@@ -16,7 +13,25 @@ namespace Sample.RabbitMQ.PostgreSql
         // This method gets called by the runtime. Use this method to add services to the container.
         public void ConfigureServices(IServiceCollection services)
         {
-            
+            services.AddCap(x =>
+            {
+                x.UseEntityFramework<AppDbContext>();
+                x.UseRabbitMQ(z =>
+                {
+                    z.HostName = "192.168.2.206";
+                    z.UserName = "admin";
+                    z.Password = "123123";
+                });
+                x.UseDashboard();
+                x.UseDiscovery(d =>
+                {
+                    d.DiscoveryServerHostName = "localhost";
+                    d.DiscoveryServerProt = 8500;
+                    d.CurrentNodeHostName = "localhost";
+                    d.CurrentNodePort = 5800;
+                    d.NodeName = "CAP一号节点";
+                });
+            });
             services.AddMvc();
         }
 
@@ -24,6 +39,8 @@ namespace Sample.RabbitMQ.PostgreSql
         public void Configure(IApplicationBuilder app, IHostingEnvironment env)
         {
             app.UseMvc();
+
+            app.UseCap();
         }
     }
 }

samples/Sample.RabbitMQ.SqlServer/Startup.cs

 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
-using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Sample.RabbitMQ.SqlServer.Services;
@@ -26,7 +25,7 @@ namespace Sample.RabbitMQ.SqlServer
                     z.UserName = "admin";
                     z.Password = "123123";
                 });
-                x.UseDashboard();
+                x.UseDashboard(d => { d.StatsPollingInterval = 1000000; });
                 x.UseDiscovery(d =>
                 {
                     d.DiscoveryServerHostName = "localhost";
@@ -48,8 +47,6 @@ namespace Sample.RabbitMQ.SqlServer
             app.UseMvc();
 
             app.UseCap();
-
-            app.UseCapDashboard();
         }
     }
 }
\ No newline at end of file

src/DotNetCore.CAP/CAP.AppBuilderExtensions.cs

@@ -26,24 +26,18 @@ namespace Microsoft.AspNetCore.Builder
             CheckRequirement(app);
 
             var provider = app.ApplicationServices;
+
             var bootstrapper = provider.GetRequiredService<IBootstrapper>();
             bootstrapper.BootstrapAsync();
-            return app;
-        }
 
-        ///<summary>
-        /// Enables cap dashboard for the current application
-        /// </summary>
-        /// <param name="app">The <see cref="IApplicationBuilder"/> instance this method extends.</param>
-        /// <returns>The <see cref="IApplicationBuilder"/> instance this method extends.</returns>
-        public static IApplicationBuilder UseCapDashboard(this IApplicationBuilder app)
-        {
-            if (app == null) throw new ArgumentNullException(nameof(app));
-
-            CheckRequirement(app);
-
-            app.UseMiddleware<GatewayProxyMiddleware>();
-            app.UseMiddleware<DashboardMiddleware>();
+            if (provider.GetService<DashboardOptions>() != null)
+            {
+                if (provider.GetService<DiscoveryOptions>() != null)
+                {
+                    app.UseMiddleware<GatewayProxyMiddleware>();
+                }
+                app.UseMiddleware<DashboardMiddleware>();
+            }
 
             return app;
         }

src/DotNetCore.CAP/Dashboard/CAP.DashboardMiddleware.cs

@@ -25,49 +25,44 @@ namespace DotNetCore.CAP
 
         public Task Invoke(HttpContext context)
         {
-            if (context.Request.Path.StartsWithSegments(_options.PathMatch, 
-                out var matchedPath, out var remainingPath))
+            if (!context.Request.Path.StartsWithSegments(_options.PathMatch,
+                out var matchedPath, out var remainingPath)) return _next(context);
+
+            // Update the path
+            var path = context.Request.Path;
+            var pathBase = context.Request.PathBase;
+            context.Request.PathBase = pathBase.Add(matchedPath);
+            context.Request.Path = remainingPath;
+
+            try
             {
-                // Update the path
-                var path = context.Request.Path;
-                var pathBase = context.Request.PathBase;
-                context.Request.PathBase = pathBase.Add(matchedPath);
-                context.Request.Path = remainingPath;
+                var dashboardContext = new CapDashboardContext(_storage, _options, context);
+                var findResult = _routes.FindDispatcher(context.Request.Path.Value);
 
-                try
+                if (findResult == null)
                 {
-                    var dashboardContext = new CapDashboardContext(_storage, _options, context);
-                    var findResult = _routes.FindDispatcher(context.Request.Path.Value);
-
-                    if (findResult == null)
-                    {
-                        return _next.Invoke(context);
-                    }
+                    return _next.Invoke(context);
+                }
 
-                    if (_options.Authorization.Any(filter => !filter.Authorize(dashboardContext)))
-                    {
-                        var isAuthenticated = context.User?.Identity?.IsAuthenticated;
+                if (_options.Authorization.Any(filter => !filter.Authorize(dashboardContext)))
+                {
+                    var isAuthenticated = context.User?.Identity?.IsAuthenticated;
 
-                        context.Response.StatusCode = isAuthenticated == true
-                            ? (int)HttpStatusCode.Forbidden
-                            : (int)HttpStatusCode.Unauthorized;
+                    context.Response.StatusCode = isAuthenticated == true
+                        ? (int)HttpStatusCode.Forbidden
+                        : (int)HttpStatusCode.Unauthorized;
 
-                        return Task.CompletedTask;
-                    }
+                    return Task.CompletedTask;
+                }
 
-                    dashboardContext.UriMatch = findResult.Item2;
+                dashboardContext.UriMatch = findResult.Item2;
 
-                    return findResult.Item1.Dispatch(dashboardContext);
-                }
-                finally
-                {
-                    context.Request.PathBase = pathBase;
-                    context.Request.Path = path;
-                }
+                return findResult.Item1.Dispatch(dashboardContext);
             }
-            else
+            finally
             {
-                return _next(context);
+                context.Request.PathBase = pathBase;
+                context.Request.Path = path;
             }
         }
     }

src/DotNetCore.CAP/Dashboard/GatewayProxy/GatewayProxyMiddleware.cs

@@ -46,40 +46,48 @@ namespace DotNetCore.CAP.Dashboard.GatewayProxy
             var request = context.Request;
             var pathMatch = discoveryOptions.MatchPath;
             var isCapRequest = request.Path.StartsWithSegments(new PathString(pathMatch));
-
-            var isSwitchNode = request.Cookies.TryGetValue(NodeCookieName, out string requestNodeId);
-            var isCurrentNode = discoveryOptions.NodeId.ToString() == requestNodeId;
-
-            if (!isCapRequest || !isSwitchNode || isCurrentNode)
+            if (!isCapRequest)
             {
                 await _next.Invoke(context);
             }
             else
             {
-                _logger.LogDebug("started calling gateway proxy middleware");
+                //For performance reasons, we need to put this functionality in the else
+                var isSwitchNode = request.Cookies.TryGetValue(NodeCookieName, out string requestNodeId);
+                var isCurrentNode = discoveryOptions.NodeId.ToString() == requestNodeId;
+                var isNodesPage = request.Path.StartsWithSegments(new PathString(pathMatch + "/nodes"));
 
-                if (TryGetRemoteNode(requestNodeId, out Node node))
+                if (!isSwitchNode || isCurrentNode || isNodesPage)
+                {
+                    await _next.Invoke(context);
+                }
+                else
                 {
-                    try
+                    _logger.LogDebug("started calling gateway proxy middleware");
+
+                    if (TryGetRemoteNode(requestNodeId, out Node node))
                     {
-                        DownstreamRequest = await _requestMapper.Map(request);
+                        try
+                        {
+                            DownstreamRequest = await _requestMapper.Map(request);
 
-                        SetDownStreamRequestUri(node, request.Path.Value);
+                            SetDownStreamRequestUri(node, request.Path.Value);
 
-                        var response = await _requester.GetResponse(DownstreamRequest);
+                            var response = await _requester.GetResponse(DownstreamRequest);
 
-                        await SetResponseOnHttpContext(context, response);
+                            await SetResponseOnHttpContext(context, response);
+                        }
+                        catch (Exception ex)
+                        {
+                            _logger.LogError(ex.Message);
+                        }
                     }
-                    catch(Exception ex)
+                    else
                     {
-                        _logger.LogError(ex.Message);
+                        context.Response.Cookies.Delete(NodeCookieName);
+                        await _next.Invoke(context);
                     }
                 }
-                else
-                {
-                    context.Response.Cookies.Delete(NodeCookieName);
-                    await _next.Invoke(context);
-                }
             }
         }
 
@@ -90,10 +98,9 @@ namespace DotNetCore.CAP.Dashboard.GatewayProxy
                 AddHeaderIfDoesntExist(context, httpResponseHeader);
             }
 
-            var stringContent = await response.Content.ReadAsStringAsync();
             var content = await response.Content.ReadAsByteArrayAsync();
 
-            AddHeaderIfDoesntExist(context, 
+            AddHeaderIfDoesntExist(context,
                 new KeyValuePair<string, IEnumerable<string>>("Content-Length", new[] { content.Length.ToString() }));
 
             context.Response.OnStarting(state =>
@@ -128,7 +135,7 @@ namespace DotNetCore.CAP.Dashboard.GatewayProxy
             DownstreamRequest.RequestUri = uriBuilder.Uri;
         }
 
-        private static void AddHeaderIfDoesntExist(HttpContext context, 
+        private static void AddHeaderIfDoesntExist(HttpContext context,
             KeyValuePair<string, IEnumerable<string>> httpResponseHeader)
         {
             if (!context.Response.Headers.ContainsKey(httpResponseHeader.Key))

src/DotNetCore.CAP/Dashboard/JsonDispatcher.cs

@@ -42,7 +42,7 @@ namespace DotNetCore.CAP.Dashboard
             }
 
             context.Response.ContentType = "application/json";
-            await context.Response.WriteAsync(serialized);
+            await context.Response.WriteAsync(serialized ?? string.Empty);
         }
     }
 }
\ No newline at end of file

src/DotNetCore.CAP/IQueueExecutor.Subscibe.cs

@@ -124,7 +124,6 @@ namespace DotNetCore.CAP
         {
             var retryBehavior = RetryBehavior.DefaultRetry;
 
-            var now = DateTime.Now;
             var retries = ++message.Retries;
             if (retries >= retryBehavior.RetryCount)
             {