write log when message move to dead letter

framework/src/Volo.Abp.EventBus.Kafka/Volo/Abp/EventBus/Kafka/KafkaEventErrorHandler.cs

@@ -3,6 +3,8 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using Confluent.Kafka;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging.Abstractions;
 using Microsoft.Extensions.Options;
 using Volo.Abp.Data;
 using Volo.Abp.DependencyInjection;
@@ -11,9 +13,12 @@ namespace Volo.Abp.EventBus.Kafka
 {
     public class KafkaEventErrorHandler : EventErrorHandlerBase, ISingletonDependency
     {
+        protected ILogger<KafkaEventErrorHandler> Logger { get; set; }
+
         public KafkaEventErrorHandler(
             IOptions<AbpEventBusOptions> options) : base(options)
         {
+            Logger = NullLogger<KafkaEventErrorHandler>.Instance;
         }
 
         protected override async Task Retry(EventExecutionErrorContext context)
@@ -34,6 +39,10 @@ namespace Volo.Abp.EventBus.Kafka
 
         protected override async Task MoveToDeadLetter(EventExecutionErrorContext context)
         {
+            Logger.LogException(
+                context.Exceptions.Count == 1 ? context.Exceptions.First() : new AggregateException(context.Exceptions),
+                LogLevel.Error);
+
             await context.EventBus.As<KafkaDistributedEventBus>().PublishToDeadLetterAsync(
                 context.EventType,
                 context.EventData,