Fix Netty deprecation warnings in transport-netty4 module (opensearch-project#20233)

* Fix Netty deprecation warnings in transport-netty4 module

Signed-off-by: Sergei Ustimenko <fdesu@proton.me>

* Add the CHANGELOG entry and run spotless

Signed-off-by: Sergei Ustimenko <fdesu@proton.me>

---------

Signed-off-by: Sergei Ustimenko <fdesu@proton.me>

Author: fdesu

CHANGELOG.md

@@ -17,6 +17,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Fix bug of warm index: FullFileCachedIndexInput was closed error ([#20055](https://github.com/opensearch-project/OpenSearch/pull/20055))
 - Fix flaky test ClusterMaxMergesAtOnceIT.testClusterLevelDefaultUpdatesMergePolicy ([#18056](https://github.com/opensearch-project/OpenSearch/issues/18056))
 - Fix bug in Assertion framework(Yaml Rest test): numeric comparison fails when comparing Integer vs Long (or Float vs Double) ([#19376](https://github.com/opensearch-project/OpenSearch/pull/19376))
+- Fix Netty deprecation warnings in transport-netty4 module ([#20233](https://github.com/opensearch-project/OpenSearch/pull/20233))
 
 ### Dependencies
 - Bump `com.google.auth:google-auth-library-oauth2-http` from 1.38.0 to 1.41.0 ([#20183](https://github.com/opensearch-project/OpenSearch/pull/20183))

modules/transport-netty4/src/main/java/org/opensearch/http/netty4/Netty4HttpServerTransport.java

@@ -139,6 +139,11 @@ public class Netty4HttpServerTransport extends AbstractHttpServerTransport {
      */
     private static final ByteSizeValue MTU = new ByteSizeValue(Long.parseLong(System.getProperty("opensearch.net.mtu", "1500")));
 
+    /**
+     * The size of the http content decompressor buffer that is going to be used with the {@link #createDecompressor()}.
+     */
+    private static final int UNLIMITED_DECOMPRESSOR_BUFFER = 0;
+
     private static final String SETTING_KEY_HTTP_NETTY_MAX_COMPOSITE_BUFFER_COMPONENTS = "http.netty.max_composite_buffer_components";
 
     public static Setting<Integer> SETTING_HTTP_NETTY_MAX_COMPOSITE_BUFFER_COMPONENTS = new Setting<>(
@@ -310,8 +315,8 @@ protected void doStart() {
                 serverBootstrap.childOption(ChannelOption.SO_RCVBUF, Math.toIntExact(tcpReceiveBufferSize.getBytes()));
             }
 
-            serverBootstrap.option(ChannelOption.RCVBUF_ALLOCATOR, recvByteBufAllocator);
-            serverBootstrap.childOption(ChannelOption.RCVBUF_ALLOCATOR, recvByteBufAllocator);
+            serverBootstrap.option(ChannelOption.RECVBUF_ALLOCATOR, recvByteBufAllocator);
+            serverBootstrap.childOption(ChannelOption.RECVBUF_ALLOCATOR, recvByteBufAllocator);
 
             final boolean reuseAddress = SETTING_HTTP_TCP_REUSE_ADDRESS.get(settings);
             serverBootstrap.option(ChannelOption.SO_REUSEADDR, reuseAddress);
@@ -575,7 +580,7 @@ protected ChannelInboundHandlerAdapter createHeaderVerifier() {
      * Used in instances to conditionally decompress depending on the outcome from header verification
      */
     protected ChannelInboundHandlerAdapter createDecompressor() {
-        return new HttpContentDecompressor();
+        return new HttpContentDecompressor(UNLIMITED_DECOMPRESSOR_BUFFER);
     }
 
     /**

modules/transport-netty4/src/main/java/org/opensearch/transport/NettyAllocator.java

@@ -117,7 +117,6 @@ public class NettyAllocator {
                         maxOrder = 5;
                     }
                 }
-                int tinyCacheSize = PooledByteBufAllocator.defaultTinyCacheSize();
                 int smallCacheSize = PooledByteBufAllocator.defaultSmallCacheSize();
                 int normalCacheSize = PooledByteBufAllocator.defaultNormalCacheSize();
                 boolean useCacheForAllThreads = PooledByteBufAllocator.defaultUseCacheForAllThreads();
@@ -127,7 +126,6 @@ public class NettyAllocator {
                     0,
                     pageSize,
                     maxOrder,
-                    tinyCacheSize,
                     smallCacheSize,
                     normalCacheSize,
                     useCacheForAllThreads

modules/transport-netty4/src/main/java/org/opensearch/transport/SharedGroupFactory.java

@@ -44,7 +44,8 @@
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import io.netty.channel.EventLoopGroup;
-import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.MultiThreadIoEventLoopGroup;
+import io.netty.channel.nio.NioIoHandler;
 import io.netty.util.concurrent.Future;
 
 import static org.opensearch.common.util.concurrent.OpenSearchExecutors.daemonThreadFactory;
@@ -89,9 +90,10 @@ public synchronized SharedGroup getHttpGroup() {
             return getGenericGroup();
         } else {
             if (dedicatedHttpGroup == null) {
-                NioEventLoopGroup eventLoopGroup = new NioEventLoopGroup(
+                EventLoopGroup eventLoopGroup = new MultiThreadIoEventLoopGroup(
                     httpWorkerCount,
-                    daemonThreadFactory(settings, HttpServerTransport.HTTP_SERVER_WORKER_THREAD_NAME_PREFIX)
+                    daemonThreadFactory(settings, HttpServerTransport.HTTP_SERVER_WORKER_THREAD_NAME_PREFIX),
+                    NioIoHandler.newFactory()
                 );
                 dedicatedHttpGroup = new SharedGroup(new RefCountedGroup(eventLoopGroup));
             }
@@ -101,9 +103,10 @@ public synchronized SharedGroup getHttpGroup() {
 
     private SharedGroup getGenericGroup() {
         if (genericGroup == null) {
-            EventLoopGroup eventLoopGroup = new NioEventLoopGroup(
+            EventLoopGroup eventLoopGroup = new MultiThreadIoEventLoopGroup(
                 workerCount,
-                daemonThreadFactory(settings, TcpTransport.TRANSPORT_WORKER_THREAD_NAME_PREFIX)
+                daemonThreadFactory(settings, TcpTransport.TRANSPORT_WORKER_THREAD_NAME_PREFIX),
+                NioIoHandler.newFactory()
             );
             this.genericGroup = new RefCountedGroup(eventLoopGroup);
         } else {

modules/transport-netty4/src/main/java/org/opensearch/transport/netty4/Netty4Transport.java

@@ -218,7 +218,7 @@ private Bootstrap createClientBootstrap(SharedGroupFactory.SharedGroup sharedGro
             bootstrap.option(ChannelOption.SO_RCVBUF, Math.toIntExact(tcpReceiveBufferSize.getBytes()));
         }
 
-        bootstrap.option(ChannelOption.RCVBUF_ALLOCATOR, recvByteBufAllocator);
+        bootstrap.option(ChannelOption.RECVBUF_ALLOCATOR, recvByteBufAllocator);
 
         final boolean reuseAddress = TransportSettings.TCP_REUSE_ADDRESS.get(settings);
         bootstrap.option(ChannelOption.SO_REUSEADDR, reuseAddress);
@@ -288,8 +288,8 @@ private void createServerBootstrap(ProfileSettings profileSettings, SharedGroupF
             serverBootstrap.childOption(ChannelOption.SO_RCVBUF, Math.toIntExact(profileSettings.receiveBufferSize.bytesAsInt()));
         }
 
-        serverBootstrap.option(ChannelOption.RCVBUF_ALLOCATOR, recvByteBufAllocator);
-        serverBootstrap.childOption(ChannelOption.RCVBUF_ALLOCATOR, recvByteBufAllocator);
+        serverBootstrap.option(ChannelOption.RECVBUF_ALLOCATOR, recvByteBufAllocator);
+        serverBootstrap.childOption(ChannelOption.RECVBUF_ALLOCATOR, recvByteBufAllocator);
 
         serverBootstrap.option(ChannelOption.SO_REUSEADDR, profileSettings.reuseAddress);
         serverBootstrap.childOption(ChannelOption.SO_REUSEADDR, profileSettings.reuseAddress);