diff --git a/samples/Sample.RabbitMQ.SqlServer/Controllers/ValuesController.cs b/samples/Sample.RabbitMQ.SqlServer/Controllers/ValuesController.cs
index c7e32dc..bb75269 100644
--- a/samples/Sample.RabbitMQ.SqlServer/Controllers/ValuesController.cs
+++ b/samples/Sample.RabbitMQ.SqlServer/Controllers/ValuesController.cs
@@ -2,6 +2,7 @@
 using System.Threading.Tasks;
 using Dapper;
 using DotNetCore.CAP;
+using DotNetCore.CAP.Messages;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Data.SqlClient;
 
@@ -77,6 +78,8 @@ namespace Sample.RabbitMQ.SqlServer.Controllers
         [CapSubscribe("sample.rabbitmq.sqlserver", Group = "group.test2")]
         public void Subscriber2(Person p, [FromCap]CapHeader header)
         {
+            var id = header[Headers.MessageId];
+
             Console.WriteLine($@"{DateTime.Now} Subscriber invoked, Info: {p}");
         }
     }
diff --git a/src/DotNetCore.CAP/Processor/IDispatcher.Default.cs b/src/DotNetCore.CAP/Processor/IDispatcher.Default.cs
index 2139ee1..d2f21cc 100644
--- a/src/DotNetCore.CAP/Processor/IDispatcher.Default.cs
+++ b/src/DotNetCore.CAP/Processor/IDispatcher.Default.cs
@@ -34,10 +34,11 @@ namespace DotNetCore.CAP.Processor
             _sender = sender;
             _executor = executor;
 
-            _publishedChannel = Channel.CreateUnbounded<MediumMessage>(new UnboundedChannelOptions() { SingleReader = true, SingleWriter = true });
+            _publishedChannel = Channel.CreateUnbounded<MediumMessage>(new UnboundedChannelOptions() { SingleReader = false, SingleWriter = true });
             _receivedChannel = Channel.CreateUnbounded<(MediumMessage, ConsumerExecutorDescriptor)>();
 
-            Task.Factory.StartNew(Sending, _cts.Token, TaskCreationOptions.LongRunning, TaskScheduler.Default);
+            Task.WhenAll(Enumerable.Range(0, options.Value.ProducerThreadCount)
+                .Select(_ => Task.Factory.StartNew(Sending, _cts.Token, TaskCreationOptions.LongRunning, TaskScheduler.Default)).ToArray());
 
             Task.WhenAll(Enumerable.Range(0, options.Value.ConsumerThreadCount)
                 .Select(_ => Task.Factory.StartNew(Processing, _cts.Token, TaskCreationOptions.LongRunning, TaskScheduler.Default)).ToArray());