Created ExceptionSubscriber.

framework/src/Volo.Abp.Core/Volo/Abp/DependencyInjection/ExposedServiceExplorer.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Reflection;
 
 namespace Volo.Abp.DependencyInjection
 {
@@ -17,10 +16,11 @@ namespace Volo.Abp.DependencyInjection
         public static List<Type> GetExposedServices(Type type)
         {
             return type
-                .GetCustomAttributes()
+                .GetCustomAttributes(true)
                 .OfType<IExposedServiceTypesProvider>()
                 .DefaultIfEmpty(DefaultExposeServicesAttribute)
                 .SelectMany(p => p.GetExposedServiceTypes(type))
+                .Distinct()
                 .ToList();
         }
     }

framework/src/Volo.Abp.Core/Volo/Abp/ExceptionHandling/ExceptionSubscriber.cs

@@ -0,0 +1,11 @@
+using System.Threading.Tasks;
+using Volo.Abp.DependencyInjection;
+
+namespace Volo.Abp.ExceptionHandling
+{
+    [ExposeServices(typeof(IExceptionSubscriber))]
+    public abstract class ExceptionSubscriber : IExceptionSubscriber, ITransientDependency
+    {
+        public abstract Task HandleAsync(ExceptionNotificationContext context);
+    }
+}