Update netty version to the latest.

In the updated netty pool,
`ChannelPoolHandler#channelCreated` is called at channel creation, and then `ChannelPoolHandler#channelAcquired` is called when the connection is borrowed out of the pool. When acquiring a connection from a newly created pool, a new connection will be created and then acquired. In previous netty version, when a connection is created, then it is directly lent out of the pool without being acquired. Thus we need to change some logic regarding how to count in use and idle connections.

Author: Zhen Li

driver/src/main/java/org/neo4j/driver/internal/async/pool/NettyChannelTracker.java

@@ -91,9 +91,8 @@ public void channelCreated( Channel channel, ListenerEvent creatingEvent )
         log.debug( "Channel [0x%s] created. Local address: %s, remote address: %s",
                 channel.id(), channel.localAddress(), channel.remoteAddress() );
 
-        incrementInUse( channel );
+        incrementIdle( channel ); // when it is created, we count it as idle as it has not been acquired out of the pool
         metricsListener.afterCreated( poolId( channel ), creatingEvent );
-
         allChannels.add( channel );
     }
 

driver/src/test/java/org/neo4j/driver/internal/async/pool/ConnectionPoolImplIT.java

@@ -123,7 +123,7 @@ void shouldFailToAcquireConnectionWhenPoolIsClosed()
                 assertThrows( ServiceUnavailableException.class, () -> await( pool.acquire( neo4j.address() ) ) );
         assertThat( error.getMessage(), containsString( "closed while acquiring a connection" ) );
         assertThat( error.getCause(), instanceOf( IllegalStateException.class ) );
-        assertThat( error.getCause().getMessage(), containsString( "FixedChannelPooled was closed" ) );
+        assertThat( error.getCause().getMessage(), containsString( "FixedChannelPool was closed" ) );
     }
 
     private ConnectionPoolImpl newPool() throws Exception

driver/src/test/java/org/neo4j/driver/internal/async/pool/NettyChannelTrackerTest.java

@@ -49,15 +49,15 @@ class NettyChannelTrackerTest
     private final NettyChannelTracker tracker = new NettyChannelTracker( DEV_NULL_METRICS, mock( ChannelGroup.class ), DEV_NULL_LOGGING );
 
     @Test
-    void shouldIncrementInUseCountWhenChannelCreated()
+    void shouldIncrementIdleCountWhenChannelCreated()
     {
         Channel channel = newChannel();
         assertEquals( 0, tracker.inUseChannelCount( address ) );
         assertEquals( 0, tracker.idleChannelCount( address ) );
 
         tracker.channelCreated( channel, null );
-        assertEquals( 1, tracker.inUseChannelCount( address ) );
-        assertEquals( 0, tracker.idleChannelCount( address ) );
+        assertEquals( 0, tracker.inUseChannelCount( address ) );
+        assertEquals( 1, tracker.idleChannelCount( address ) );
     }
 
     @Test
@@ -68,33 +68,45 @@ void shouldIncrementInUseCountWhenChannelAcquired()
         assertEquals( 0, tracker.idleChannelCount( address ) );
 
         tracker.channelCreated( channel, null );
+        assertEquals( 0, tracker.inUseChannelCount( address ) );
+        assertEquals( 1, tracker.idleChannelCount( address ) );
+
+        tracker.channelAcquired( channel );
         assertEquals( 1, tracker.inUseChannelCount( address ) );
         assertEquals( 0, tracker.idleChannelCount( address ) );
+    }
 
-        tracker.channelReleased( channel );
+    @Test
+    void shouldIncrementIdleCountWhenChannelReleased()
+    {
+        Channel channel = newChannel();
         assertEquals( 0, tracker.inUseChannelCount( address ) );
-        assertEquals( 1, tracker.idleChannelCount( address ) );
+        assertEquals( 0, tracker.idleChannelCount( address ) );
 
-        tracker.channelAcquired( channel );
+        channelCreatedAndAcquired( channel );
         assertEquals( 1, tracker.inUseChannelCount( address ) );
         assertEquals( 0, tracker.idleChannelCount( address ) );
+
+        tracker.channelReleased( channel );
+        assertEquals( 0, tracker.inUseChannelCount( address ) );
+        assertEquals( 1, tracker.idleChannelCount( address ) );
     }
 
     @Test
-    void shouldIncrementInuseCountForAddress()
+    void shouldIncrementIdleCountForAddress()
     {
         Channel channel1 = newChannel();
         Channel channel2 = newChannel();
         Channel channel3 = newChannel();
 
-        assertEquals( 0, tracker.inUseChannelCount( address ) );
+        assertEquals( 0, tracker.idleChannelCount( address ) );
         tracker.channelCreated( channel1, null );
-        assertEquals( 1, tracker.inUseChannelCount( address ) );
+        assertEquals( 1, tracker.idleChannelCount( address ) );
         tracker.channelCreated( channel2, null );
-        assertEquals( 2, tracker.inUseChannelCount( address ) );
+        assertEquals( 2, tracker.idleChannelCount( address ) );
         tracker.channelCreated( channel3, null );
-        assertEquals( 3, tracker.inUseChannelCount( address ) );
-        assertEquals( 0, tracker.idleChannelCount( address ) );
+        assertEquals( 3, tracker.idleChannelCount( address ) );
+        assertEquals( 0, tracker.inUseChannelCount( address ) );
     }
 
     @Test
@@ -104,9 +116,9 @@ void shouldDecrementCountForAddress()
         Channel channel2 = newChannel();
         Channel channel3 = newChannel();
 
-        tracker.channelCreated( channel1, null );
-        tracker.channelCreated( channel2, null );
-        tracker.channelCreated( channel3, null );
+        channelCreatedAndAcquired( channel1 );
+        channelCreatedAndAcquired( channel2 );
+        channelCreatedAndAcquired( channel3 );
         assertEquals( 3, tracker.inUseChannelCount( address ) );
         assertEquals( 0, tracker.idleChannelCount( address ) );
 
@@ -126,7 +138,7 @@ void shouldDecreaseIdleWhenClosedOutsidePool() throws Throwable
     {
         // Given
         Channel channel = newChannel();
-        tracker.channelCreated( channel, null );
+        channelCreatedAndAcquired( channel );
         assertEquals( 1, tracker.inUseChannelCount( address ) );
         assertEquals( 0, tracker.idleChannelCount( address ) );
 
@@ -147,7 +159,7 @@ void shouldDecreaseIdleWhenClosedInsidePool() throws Throwable
     {
         // Given
         Channel channel = newChannel();
-        tracker.channelCreated( channel, null );
+        channelCreatedAndAcquired( channel );
         assertEquals( 1, tracker.inUseChannelCount( address ) );
         assertEquals( 0, tracker.idleChannelCount( address ) );
 
@@ -160,7 +172,6 @@ void shouldDecreaseIdleWhenClosedInsidePool() throws Throwable
         // Then
         assertEquals( 0, tracker.inUseChannelCount( address ) );
         assertEquals( 0, tracker.idleChannelCount( address ) );
-
     }
 
     @Test
@@ -226,4 +237,10 @@ private EmbeddedChannel newChannelWithProtocolV3()
         setMessageDispatcher( channel, mock( InboundMessageDispatcher.class ) );
         return channel;
     }
+
+    private void channelCreatedAndAcquired( Channel channel )
+    {
+        tracker.channelCreated( channel, null );
+        tracker.channelAcquired( channel );
+    }
 }

driver/src/test/java/org/neo4j/driver/internal/cluster/loadbalancing/RoutingTableAndConnectionPoolTest.java

@@ -407,7 +407,10 @@ private static class PooledConnection implements Connection
             this.channel = channel;
             this.pool = pool;
 
-            this.channel.attr( AttributeKey.valueOf( "channelPool" ) ).setIfAbsent( pool );
+            // This is needed to make netty connection pool to believe this channel is created by the pool.
+            // Otherwise the netty connection pool will refuse to release the channel back to the pool.
+            AttributeKey<ExtendedChannelPool> poolKey = AttributeKey.valueOf( "channelPool." + System.identityHashCode( pool ) );
+            this.channel.attr( poolKey ).setIfAbsent( pool );
         }
 
         @Override

pom.xml

@@ -64,7 +64,7 @@
       <dependency>
         <groupId>io.netty</groupId>
         <artifactId>netty-handler</artifactId>
-        <version>4.1.22.Final</version>
+        <version>4.1.41.Final</version>
       </dependency>
       <dependency>
         <groupId>io.projectreactor</groupId>