From db0871ce8b82763c934ca88428589ecb00cd882a Mon Sep 17 00:00:00 2001
From: Edward <edwardchuconnect@gmail.com>
Date: Fri, 10 Jul 2026 18:15:23 +0100
Subject: [PATCH] Don't increment client metrics on messaging service
 connection unpause

patch by Edward Chu; reviewed by Aleksey Yeschenko for CASSANDRA-21491
---
 CHANGES.txt                                                | 1 +
 .../org/apache/cassandra/net/AbstractMessageHandler.java   | 7 +++++--
 .../org/apache/cassandra/transport/CQLMessageHandler.java  | 6 ++++++
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/CHANGES.txt b/CHANGES.txt
index d2bf6142c9..2ba83fed8b 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,4 +1,5 @@
 7.0
+ * Don't increment client metrics on messaging service connection unpause (CASSANDRA-21491)
  * Add nodetool getreplicas (CASSANDRA-17665)
  * Implementation of CEP-49: Hardware-accelerated compression (CASSANDRA-20975)
  * Avoid using ObjectUtils.getFirstNonNull in Schema (CASSANDRA-21394)
diff --git a/src/java/org/apache/cassandra/net/AbstractMessageHandler.java b/src/java/org/apache/cassandra/net/AbstractMessageHandler.java
index 0ef03990fd..abbd5c77b9 100644
--- a/src/java/org/apache/cassandra/net/AbstractMessageHandler.java
+++ b/src/java/org/apache/cassandra/net/AbstractMessageHandler.java
@@ -31,7 +31,6 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import org.apache.cassandra.concurrent.ManyToOneConcurrentLinkedQueue;
-import org.apache.cassandra.metrics.ClientMetrics;
 import org.apache.cassandra.net.FrameDecoder.CorruptFrame;
 import org.apache.cassandra.net.FrameDecoder.Frame;
 import org.apache.cassandra.net.FrameDecoder.FrameProcessor;
@@ -314,7 +313,7 @@ public abstract class AbstractMessageHandler extends ChannelInboundHandlerAdapte
                 decoder.reactivate();
 
                 if (decoder.isActive())
-                    ClientMetrics.instance.unpauseConnection();
+                    onConnectionUnpaused();
             }
         }
         catch (Throwable t)
@@ -323,6 +322,10 @@ public abstract class AbstractMessageHandler extends ChannelInboundHandlerAdapte
         }
     }
 
+    protected void onConnectionUnpaused()
+    {
+    }
+
     protected abstract void fatalExceptionCaught(Throwable t);
 
     // return true if the handler should be reactivated - if no new hurdles were encountered,
diff --git a/src/java/org/apache/cassandra/transport/CQLMessageHandler.java b/src/java/org/apache/cassandra/transport/CQLMessageHandler.java
index 2486497c2f..2f764660a8 100644
--- a/src/java/org/apache/cassandra/transport/CQLMessageHandler.java
+++ b/src/java/org/apache/cassandra/transport/CQLMessageHandler.java
@@ -159,6 +159,12 @@ public class CQLMessageHandler<M extends Message> extends AbstractMessageHandler
         return super.process(frame);
     }
 
+    @Override
+    protected void onConnectionUnpaused()
+    {
+        ClientMetrics.instance.unpauseConnection();
+    }
+
     /**
      * Checks limits on bytes in flight and the request rate limiter (if enabled), then takes one of three actions:
      *