From 5ded050f7bb0b046892623194291b1ab021a5510 Mon Sep 17 00:00:00 2001
From: Dmitriy Dumanskiy <doom369@gmail.com>
Date: Mon, 1 Jul 2019 21:38:59 +0300
Subject: [PATCH] #7285 Improved "Discarded inbound message" warning (#9286)

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
---
 .../io/netty/channel/DefaultChannelPipeline.java  | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/transport/src/main/java/io/netty/channel/DefaultChannelPipeline.java b/transport/src/main/java/io/netty/channel/DefaultChannelPipeline.java
index 9017f14e6c..f40c6ddc01 100644
--- a/transport/src/main/java/io/netty/channel/DefaultChannelPipeline.java
+++ b/transport/src/main/java/io/netty/channel/DefaultChannelPipeline.java
@@ -1198,6 +1198,19 @@ public class DefaultChannelPipeline implements ChannelPipeline {
         }
     }
 
+    /**
+     * Called once a message hit the end of the {@link ChannelPipeline} without been handled by the user
+     * 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(ChannelHandlerContext ctx, Object msg) {
+        onUnhandledInboundMessage(msg);
+        if (logger.isDebugEnabled()) {
+            logger.debug("Discarded message pipeline : {}. Channel : {}.",
+                         ctx.pipeline().names(), ctx.channel());
+        }
+    }
+
     /**
      * Called once the {@link ChannelInboundHandler#channelReadComplete(ChannelHandlerContext)} event hit
      * the end of the {@link ChannelPipeline}.
@@ -1291,7 +1304,7 @@ public class DefaultChannelPipeline implements ChannelPipeline {
 
         @Override
         public void channelRead(ChannelHandlerContext ctx, Object msg) {
-            onUnhandledInboundMessage(msg);
+            onUnhandledInboundMessage(ctx, msg);
         }
 
         @Override