Remove some Dead Code in o.e.transport (#44653)

* None of this is used

Author: original-brownbear

server/src/main/java/org/elasticsearch/transport/RemoteClusterConnection.java

@@ -92,7 +92,7 @@ final class RemoteClusterConnection implements TransportConnectionListener, Clos
     private volatile boolean skipUnavailable;
     private final ConnectHandler connectHandler;
     private final TimeValue initialConnectionTimeout;
-    private SetOnce<ClusterName> remoteClusterName = new SetOnce<>();
+    private final SetOnce<ClusterName> remoteClusterName = new SetOnce<>();
 
     /**
      * Creates a new {@link RemoteClusterConnection}

server/src/main/java/org/elasticsearch/transport/Transport.java

@@ -22,13 +22,12 @@
 import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.cluster.node.DiscoveryNode;
-import org.elasticsearch.common.breaker.CircuitBreaker;
-import org.elasticsearch.common.breaker.NoopCircuitBreaker;
 import org.elasticsearch.common.component.LifecycleComponent;
 import org.elasticsearch.common.transport.BoundTransportAddress;
 import org.elasticsearch.common.transport.TransportAddress;
 import org.elasticsearch.common.util.concurrent.ConcurrentCollections;
 import org.elasticsearch.common.util.concurrent.ConcurrentMapLong;
+
 import java.io.Closeable;
 import java.io.IOException;
 import java.net.UnknownHostException;
@@ -74,10 +73,6 @@ public interface Transport extends LifecycleComponent {
      */
     List<String> getDefaultSeedAddresses();
 
-    default CircuitBreaker getInFlightRequestBreaker() {
-        return new NoopCircuitBreaker("in-flight-noop");
-    }
-
     /**
      * Opens a new connection to the given node. When the connection is fully connected, the listener is called.
      * The ActionListener will be called on the calling thread or the generic thread pool.

server/src/main/java/org/elasticsearch/transport/TransportChannelResponseHandler.java

@@ -723,7 +723,7 @@ protected void doRun() throws Exception {
     }
 
     private void sendLocalRequest(long requestId, final String action, final TransportRequest request, TransportRequestOptions options) {
-        final DirectResponseChannel channel = new DirectResponseChannel(logger, localNode, action, requestId, this, threadPool);
+        final DirectResponseChannel channel = new DirectResponseChannel(localNode, action, requestId, this, threadPool);
         try {
             onRequestSent(localNode, requestId, action, request, options);
             onRequestReceived(requestId, action);
@@ -1131,16 +1131,13 @@ void setTimeoutHandler(TimeoutHandler handler) {
     }
 
     static class DirectResponseChannel implements TransportChannel {
-        final Logger logger;
         final DiscoveryNode localNode;
         private final String action;
         private final long requestId;
         final TransportService service;
         final ThreadPool threadPool;
 
-        DirectResponseChannel(Logger logger, DiscoveryNode localNode, String action, long requestId, TransportService service,
-                              ThreadPool threadPool) {
-            this.logger = logger;
+        DirectResponseChannel(DiscoveryNode localNode, String action, long requestId, TransportService service, ThreadPool threadPool) {
             this.localNode = localNode;
             this.action = action;
             this.requestId = requestId;

server/src/main/java/org/elasticsearch/transport/TransportService.java

@@ -119,9 +119,4 @@ public final class TransportSettings {
 
     private TransportSettings() {
     }
-
-    private static  <T> Setting<T> fallback(String key, Setting.AffixSetting<T> affixSetting, String regex, String replacement) {
-        return "_na_".equals(key) ? affixSetting.getConcreteSettingForNamespace(key)
-            : affixSetting.getConcreteSetting(key.replaceAll(regex, replacement));
-    }
 }