#26701 Close TcpTransport on RST in some Spots to Prevent Leaking TIME_WAIT Sockets (#26764)

 #26701 Added option to RST instead of FIN to TcpTransport#closeChannels

core/src/main/java/org/elasticsearch/transport/TcpTransport.java

@@ -442,7 +442,7 @@ public abstract class TcpTransport<Channel> extends AbstractLifecycleComponent i
         public void close() throws IOException {
             if (closed.compareAndSet(false, true)) {
                 try {
-                    closeChannels(Arrays.stream(channels).filter(Objects::nonNull).collect(Collectors.toList()), false);
+                    closeChannels(Arrays.stream(channels).filter(Objects::nonNull).collect(Collectors.toList()), false, true);
                 } finally {
                     transportService.onConnectionClosed(this);
                 }
@@ -640,7 +640,7 @@ public abstract class TcpTransport<Channel> extends AbstractLifecycleComponent i
     protected final void closeChannelWhileHandlingExceptions(final Channel channel) {
         if (isOpen(channel)) {
             try {
-                closeChannels(Collections.singletonList(channel), false);
+                closeChannels(Collections.singletonList(channel), false, false);
             } catch (IOException e) {
                 logger.warn("failed to close channel", e);
             }
@@ -902,7 +902,7 @@ public abstract class TcpTransport<Channel> extends AbstractLifecycleComponent i
                 // first stop to accept any incoming connections so nobody can connect to this transport
                 for (Map.Entry<String, List<Channel>> entry : serverChannels.entrySet()) {
                     try {
-                        closeChannels(entry.getValue(), true);
+                        closeChannels(entry.getValue(), true, true);
                     } catch (Exception e) {
                         logger.debug(
                             (Supplier<?>) () -> new ParameterizedMessage(
@@ -975,7 +975,7 @@ public abstract class TcpTransport<Channel> extends AbstractLifecycleComponent i
                     @Override
                     protected void innerInnerOnResponse(Channel channel) {
                         try {
-                            closeChannels(Collections.singletonList(channel), false);
+                            closeChannels(Collections.singletonList(channel), false, false);
                         } catch (IOException e1) {
                             logger.debug("failed to close httpOnTransport channel", e1);
                         }
@@ -984,7 +984,7 @@ public abstract class TcpTransport<Channel> extends AbstractLifecycleComponent i
                     @Override
                     protected void innerOnFailure(Exception e) {
                         try {
-                            closeChannels(Collections.singletonList(channel), false);
+                            closeChannels(Collections.singletonList(channel), false, false);
                         } catch (IOException e1) {
                             e.addSuppressed(e1);
                             logger.debug("failed to close httpOnTransport channel", e1);
@@ -1021,8 +1021,9 @@ public abstract class TcpTransport<Channel> extends AbstractLifecycleComponent i
      *
      * @param channels the channels to close
      * @param blocking whether the channels should be closed synchronously
+     * @param closingTransport whether we abort the connection on RST instead of FIN
      */
-    protected abstract void closeChannels(List<Channel> channels, boolean blocking) throws IOException;
+    protected abstract void closeChannels(List<Channel> channels, boolean blocking, boolean closingTransport) throws IOException;
 
     /**
      * Sends message to channel. The listener's onResponse method will be called when the send is complete unless an exception

core/src/test/java/org/elasticsearch/transport/TCPTransportTests.java

@@ -191,7 +191,7 @@ public class TCPTransportTests extends ESTestCase {
                 }
 
                 @Override
-                protected void closeChannels(List channel, boolean blocking) throws IOException {
+                protected void closeChannels(List channel, boolean blocking, boolean closingTransport) throws IOException {
 
                 }
 

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

@@ -331,7 +331,12 @@ public class Netty4Transport extends TcpTransport<Channel> {
     }
 
     @Override
-    protected void closeChannels(final List<Channel> channels, boolean blocking) throws IOException {
+    protected void closeChannels(final List<Channel> channels, boolean blocking, boolean closingTransport) throws IOException {
+        if (closingTransport) {
+            for (Channel channel : channels) {
+                channel.config().setOption(ChannelOption.SO_LINGER, 0);
+            }
+        }
         if (blocking) {
             Netty4Utils.closeChannels(channels);
         } else {

test/framework/src/main/java/org/elasticsearch/transport/MockTcpTransport.java

@@ -117,12 +117,12 @@ public class MockTcpTransport extends TcpTransport<MockTcpTransport.MockChannel>
     @Override
     protected MockChannel bind(final String name, InetSocketAddress address) throws IOException {
         MockServerSocket socket = new MockServerSocket();
-        socket.bind(address);
         socket.setReuseAddress(TCP_REUSE_ADDRESS.get(settings));
         ByteSizeValue tcpReceiveBufferSize = TCP_RECEIVE_BUFFER_SIZE.get(settings);
         if (tcpReceiveBufferSize.getBytes() > 0) {
             socket.setReceiveBufferSize(tcpReceiveBufferSize.bytesAsInt());
         }
+        socket.bind(address);
         MockChannel serverMockChannel = new MockChannel(socket, name);
         CountDownLatch started = new CountDownLatch(1);
         executor.execute(new AbstractRunnable() {
@@ -242,8 +242,15 @@ public class MockTcpTransport extends TcpTransport<MockTcpTransport.MockChannel>
     }
 
     @Override
-    protected void closeChannels(List<MockChannel> channel, boolean blocking) throws IOException {
-        IOUtils.close(channel);
+    protected void closeChannels(List<MockChannel> channels, boolean blocking, boolean closingTransport) throws IOException {
+        if (closingTransport) {
+            for (MockChannel channel : channels) {
+                if (channel.activeChannel != null) {
+                    channel.activeChannel.setSoLinger(true, 0);
+                }
+            }
+        }
+        IOUtils.close(channels);
     }
 
     @Override

test/framework/src/main/java/org/elasticsearch/transport/nio/NioTransport.java

@@ -19,6 +19,7 @@
 
 package org.elasticsearch.transport.nio;
 
+import java.net.StandardSocketOptions;
 import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.ExceptionsHelper;
 import org.elasticsearch.action.ActionListener;
@@ -28,7 +29,6 @@ import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
 import org.elasticsearch.common.network.NetworkService;
 import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Settings;
-import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.common.util.BigArrays;
 import org.elasticsearch.common.util.concurrent.EsExecutors;
 import org.elasticsearch.indices.breaker.CircuitBreakerService;
@@ -99,7 +99,12 @@ public class NioTransport extends TcpTransport<NioChannel> {
     }
 
     @Override
-    protected void closeChannels(List<NioChannel> channels, boolean blocking) throws IOException {
+    protected void closeChannels(List<NioChannel> channels, boolean blocking, boolean closingTransport) throws IOException {
+        if (closingTransport) {
+            for (NioChannel channel : channels) {
+                channel.getRawChannel().setOption(StandardSocketOptions.SO_LINGER, 0);
+            }
+        }
         ArrayList<CloseFuture> futures = new ArrayList<>(channels.size());
         for (final NioChannel channel : channels) {
             if (channel != null && channel.isOpen()) {