Motivation:

On servers with many pipelines or dynamic pipelines, it is easy for end user to make mistake during pipeline configuration. Current message:

`Discarded inbound message PooledUnsafeDirectByteBuf(ridx: 0, widx: 2, cap: 2) that reached at the tail of the pipeline. Please check your pipeline configuration.`

Is not always meaningful and doesn't allow to find the wrong pipeline quickly.

Modification:

Added additional log placeholder that identifies pipeline handlers and channel info. This will allow for the end users quickly find the problem pipeline.

Result:

Meaningful warning when the message reaches the end of the pipeline. Fixes #7285

transport/src/main/java/io/netty/channel/DefaultChannelPipeline.java

@@ -1043,11 +1043,12 @@ public class DefaultChannelPipeline implements ChannelPipeline {
      * in {@link ChannelInboundHandler#channelRead(ChannelHandlerContext, Object)}. This method is responsible
      * to call {@link ReferenceCountUtil#release(Object)} on the given msg at some point.
      */
-    protected void onUnhandledInboundMessage(Object msg) {
+    protected void onUnhandledInboundMessage(ChannelHandlerContext ctx, Object msg) {
         try {
             logger.debug(
                     "Discarded inbound message {} that reached at the tail of the pipeline. " +
-                            "Please check your pipeline configuration.", msg);
+                            "Please check your pipeline configuration. Discarded message pipeline : {}. Channel : {}.",
+                    msg, ctx.pipeline().names(), ctx.channel());
         } finally {
             ReferenceCountUtil.release(msg);
         }
@@ -1136,7 +1137,7 @@ public class DefaultChannelPipeline implements ChannelPipeline {
 
         @Override
         public void channelRead(ChannelHandlerContext ctx, Object msg) {
-            ((DefaultChannelPipeline) ctx.pipeline()).onUnhandledInboundMessage(msg);
+            ((DefaultChannelPipeline) ctx.pipeline()).onUnhandledInboundMessage(ctx, msg);
         }
 
         @Override

transport/src/main/java/io/netty/channel/embedded/EmbeddedChannel.java

@@ -28,6 +28,7 @@ import io.netty.channel.ChannelConfig;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandler;
+import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelId;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelMetadata;
@@ -870,7 +871,7 @@ public class EmbeddedChannel extends AbstractChannel {
         }
 
         @Override
-        protected void onUnhandledInboundMessage(Object msg) {
+        protected void onUnhandledInboundMessage(ChannelHandlerContext ctx, Object msg) {
           handleInboundMessage(msg);
         }
     }

transport/src/test/java/io/netty/channel/DefaultChannelPipelineTailTest.java

@@ -313,7 +313,7 @@ public class DefaultChannelPipelineTailTest {
             }
 
             @Override
-            protected void onUnhandledInboundMessage(Object msg) {
+            protected void onUnhandledInboundMessage(ChannelHandlerContext ctx, Object msg) {
                 MyChannel.this.onUnhandledInboundMessage(msg);
             }