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 (provider.GetService<DashboardOptions>() != null)
+            {
+                if (provider.GetService<DiscoveryOptions>() != null)
                 {
-            if (app == null) throw new ArgumentNullException(nameof(app));
-
-            CheckRequirement(app);
-
                     app.UseMiddleware<GatewayProxyMiddleware>();
+                }
                 app.UseMiddleware<DashboardMiddleware>();
+            }
 
             return app;
         }

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

@@ -25,9 +25,9 @@ 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;
@@ -65,10 +65,5 @@ namespace DotNetCore.CAP
                 context.Request.Path = path;
             }
         }
-            else
-            {
-                return _next(context);
-            }
-        }
     }
 }

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

@@ -46,11 +46,18 @@ namespace DotNetCore.CAP.Dashboard.GatewayProxy
             var request = context.Request;
             var pathMatch = discoveryOptions.MatchPath;
             var isCapRequest = request.Path.StartsWithSegments(new PathString(pathMatch));
-
+            if (!isCapRequest)
+            {
+                await _next.Invoke(context);
+            }
+            else
+            {
+                //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 (!isCapRequest || !isSwitchNode || isCurrentNode)
+                if (!isSwitchNode || isCurrentNode || isNodesPage)
                 {
                     await _next.Invoke(context);
                 }
@@ -70,7 +77,7 @@ namespace DotNetCore.CAP.Dashboard.GatewayProxy
 
                             await SetResponseOnHttpContext(context, response);
                         }
-                    catch(Exception ex)
+                        catch (Exception ex)
                         {
                             _logger.LogError(ex.Message);
                         }
@@ -82,6 +89,7 @@ namespace DotNetCore.CAP.Dashboard.GatewayProxy
                     }
                 }
             }
+        }
 
         public async Task SetResponseOnHttpContext(HttpContext context, HttpResponseMessage response)
         {
@@ -90,7 +98,6 @@ namespace DotNetCore.CAP.Dashboard.GatewayProxy
                 AddHeaderIfDoesntExist(context, httpResponseHeader);
             }
 
-            var stringContent = await response.Content.ReadAsStringAsync();
             var content = await response.Content.ReadAsByteArrayAsync();
 
             AddHeaderIfDoesntExist(context,

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)
             {