Add BrokerClient implementation

server/src/main/java/org/apache/druid/rpc/guice/ServiceClientModule.java

@@ -47,8 +47,8 @@
 
 public class ServiceClientModule implements DruidModule
 {
+  public static final int CLIENT_MAX_ATTEMPTS = 6;
   private static final int CONNECT_EXEC_THREADS = 4;
-  protected static final int CLIENT_MAX_ATTEMPTS = 6;
 
   @Override
   public void configure(Binder binder)
@@ -61,9 +61,7 @@ public void configure(Binder binder)
   @EscalatedGlobal
   public ServiceClientFactory makeServiceClientFactory(@EscalatedGlobal final HttpClient httpClient)
   {
-    final ScheduledExecutorService connectExec =
-        ScheduledExecutors.fixed(CONNECT_EXEC_THREADS, "ServiceClientFactory-%d");
-    return new ServiceClientFactoryImpl(httpClient, connectExec);
+    return getServiceClientFactory(httpClient);
   }
 
   @Provides
@@ -117,4 +115,11 @@ public CoordinatorClient makeCoordinatorClient(
         jsonMapper
     );
   }
+
+  public static ServiceClientFactory getServiceClientFactory(@EscalatedGlobal final HttpClient httpClient)
+  {
+    final ScheduledExecutorService connectExec =
+        ScheduledExecutors.fixed(CONNECT_EXEC_THREADS, "ServiceClientFactory-%d");
+    return new ServiceClientFactoryImpl(httpClient, connectExec);
+  }
 }

sql/src/main/java/org/apache/druid/sql/guice/BrokerServiceModule.java

@@ -20,13 +20,16 @@
 package org.apache.druid.sql.guice;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.google.inject.Binder;
 import com.google.inject.Provides;
 import org.apache.druid.discovery.DruidNodeDiscoveryProvider;
 import org.apache.druid.discovery.NodeRole;
 import org.apache.druid.guice.LazySingleton;
 import org.apache.druid.guice.ManageLifecycle;
 import org.apache.druid.guice.annotations.EscalatedGlobal;
 import org.apache.druid.guice.annotations.Json;
+import org.apache.druid.initialization.DruidModule;
+import org.apache.druid.java.util.http.client.HttpClient;
 import org.apache.druid.rpc.DiscoveryServiceLocator;
 import org.apache.druid.rpc.ServiceClientFactory;
 import org.apache.druid.rpc.ServiceLocator;
@@ -37,14 +40,28 @@
 import org.apache.druid.sql.client.BrokerClientImpl;
 
 /**
- * Module that processes can bind to if they require a {@link BrokerClient}.
+ * Module that processes can install if they require a {@link BrokerClient}.
  * <p>
- * This extend {@link ServiceClientModule} because the {@link BrokerClient} requires
- * classes present in the sql module.
+ * Similar to {@link ServiceClientModule}, but since {@link BrokerClient} depends
+ * on classes from the sql module, this is a separate module within the sql package.
  * </p>
  */
-public class BrokerServiceModule extends ServiceClientModule
+public class BrokerServiceModule implements DruidModule
 {
+  @Override
+  public void configure(Binder binder)
+  {
+    // Nothing to do.
+  }
+
+  @Provides
+  @LazySingleton
+  @EscalatedGlobal
+  public ServiceClientFactory makeServiceClientFactory(@EscalatedGlobal final HttpClient httpClient)
+  {
+    return ServiceClientModule.getServiceClientFactory(httpClient);
+  }
+
   @Provides
   @ManageLifecycle
   @Broker
@@ -65,7 +82,7 @@ public BrokerClient makeBrokerClient(
         clientFactory.makeClient(
             NodeRole.BROKER.getJsonName(),
             serviceLocator,
-            StandardRetryPolicy.builder().maxAttempts(CLIENT_MAX_ATTEMPTS).build()
+            StandardRetryPolicy.builder().maxAttempts(ServiceClientModule.CLIENT_MAX_ATTEMPTS).build()
         ),
         jsonMapper
     );

sql/src/test/java/org/apache/druid/sql/calcite/planner/ExplainAttributesTest.java

@@ -37,13 +37,7 @@ public class ExplainAttributesTest
   @Test
   public void testGetters()
   {
-    final ExplainAttributes selectAttributes = new ExplainAttributes(
-        "SELECT",
-        null,
-        null,
-        null,
-        null
-    );
+    final ExplainAttributes selectAttributes = new ExplainAttributes("SELECT", null, null, null, null);
     Assert.assertEquals("SELECT", selectAttributes.getStatementType());
     Assert.assertNull(selectAttributes.getTargetDataSource());
     Assert.assertNull(selectAttributes.getPartitionedBy());