Modify according to fjy's review, add reformatting according to eaclipse_formatting.xml

server/src/main/java/io/druid/segment/realtime/FireDepartmentMetrics.java

@@ -21,6 +21,8 @@ package io.druid.segment.realtime;
 
 import java.util.concurrent.atomic.AtomicLong;
 
+import com.google.common.base.Preconditions;
+
 /**
  */
 public class FireDepartmentMetrics
@@ -79,4 +81,19 @@ public class FireDepartmentMetrics
     retVal.rowOutputCount.set(rowOutputCount.get());
     return retVal;
   }
+  
+  /**
+   * merge other FireDepartmentMetrics, will modify this object's data
+   * @return this object
+   */
+	public FireDepartmentMetrics merge(FireDepartmentMetrics other)
+	{
+		Preconditions.checkNotNull(other, "Cannot merge a null FireDepartmentMetrics");
+		FireDepartmentMetrics otherSnapshot = other.snapshot();
+		processedCount.addAndGet(otherSnapshot.processed());
+		thrownAwayCount.addAndGet(otherSnapshot.thrownAway());
+		rowOutputCount.addAndGet(otherSnapshot.rowOutput());
+		unparseableCount.addAndGet(otherSnapshot.unparseable());
+		return this;
+	}
 }

server/src/main/java/io/druid/segment/realtime/RealtimeManager.java

@@ -19,6 +19,7 @@
 
 package io.druid.segment.realtime;
 
+import com.fasterxml.jackson.annotation.JacksonInject;
 import com.google.common.base.Function;
 import com.google.common.base.Preconditions;
 import com.google.common.base.Throwables;
@@ -33,6 +34,7 @@ import com.metamx.emitter.EmittingLogger;
 
 import io.druid.data.input.Firehose;
 import io.druid.data.input.InputRow;
+import io.druid.guice.annotations.Processing;
 import io.druid.query.FinalizeResultsQueryRunner;
 import io.druid.query.NoopQueryRunner;
 import io.druid.query.Query;
@@ -55,7 +57,7 @@ import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
-import java.util.concurrent.Executors;
+import java.util.concurrent.ExecutorService;
 
 /**
  */
@@ -65,20 +67,24 @@ public class RealtimeManager implements QuerySegmentWalker
 
   private final List<FireDepartment> fireDepartments;
   private final QueryRunnerFactoryConglomerate conglomerate;
+  private ExecutorService executorService;
 
 	/**
 	 * key=data source name,value=FireChiefs of all partition of that data source
 	 */
 	private final Map<String, List<FireChief>> chiefs;
 
+
   @Inject
   public RealtimeManager(
       List<FireDepartment> fireDepartments,
-      QueryRunnerFactoryConglomerate conglomerate
+      QueryRunnerFactoryConglomerate conglomerate,
+      @JacksonInject @Processing ExecutorService executorService
   )
   {
     this.fireDepartments = fireDepartments;
     this.conglomerate = conglomerate;
+		this.executorService = executorService;
 
     this.chiefs = Maps.newHashMap();
   }
@@ -90,12 +96,13 @@ public class RealtimeManager implements QuerySegmentWalker
       DataSchema schema = fireDepartment.getDataSchema();
 
 			final FireChief chief = new FireChief(fireDepartment);
-      List<FireChief> chiefsOfDataSource = chiefs.get(schema.getDataSource());
+			List<FireChief> chiefs = this.chiefs.get(schema.getDataSource());
-      if (chiefsOfDataSource == null){
+			if (chiefs == null)
-          chiefsOfDataSource = new ArrayList<RealtimeManager.FireChief>();
+			{
-          chiefs.put(schema.getDataSource(), chiefsOfDataSource);
+				chiefs = new ArrayList<RealtimeManager.FireChief>();
+				this.chiefs.put(schema.getDataSource(), chiefs);
 			}
-      chiefsOfDataSource.add(chief);
+			chiefs.add(chief);
 
 			chief.setName(String.format("chief-%s", schema.getDataSource()));
 			chief.setDaemon(true);
@@ -107,8 +114,10 @@ public class RealtimeManager implements QuerySegmentWalker
   @LifecycleStop
   public void stop()
   {
-    for (Iterable<FireChief> chiefOfDatasource : chiefs.values()) {
+		for (Iterable<FireChief> chiefs : this.chiefs.values())
-        for (FireChief chief: chiefOfDatasource) {
+		{
+			for (FireChief chief : chiefs)
+			{
 				CloseQuietly.close(chief);
 			}
 		}
@@ -116,11 +125,23 @@ public class RealtimeManager implements QuerySegmentWalker
 
   public FireDepartmentMetrics getMetrics(String datasource)
 	{
-    List<FireChief> chiefsOfDatasource = chiefs.get(datasource);
+		List<FireChief> chiefs = this.chiefs.get(datasource);
-    if (chiefsOfDatasource == null || chiefsOfDatasource.size() == 0) {
+		if (chiefs == null)
+		{
 			return null;
 		}
-    return chiefsOfDatasource.get(0).getMetrics();
+		FireDepartmentMetrics snapshot = null;
+		for (FireChief chief : chiefs)
+		{
+			if (snapshot == null)
+			{
+				snapshot = chief.getMetrics().snapshot();
+			} else
+			{
+				snapshot.merge(chief.getMetrics());
+			}
+		}
+		return snapshot;
   }
 
   @Override
@@ -134,14 +155,16 @@ public class RealtimeManager implements QuerySegmentWalker
 	{
 		QueryRunnerFactory<T, Query<T>> factory = conglomerate.findFactory(query);
 		Iterable<FireChief> chiefsOfDataSource = chiefs.get(getDataSourceName(query));
-    // the SindleThreadExecutor is only used to submit sub queries, instead of run them. 'cause can't find decent way to referrence the QueryExecutorService
 		return chiefsOfDataSource == null ? new NoopQueryRunner<T>() : factory.getToolchest().mergeResults(
-            factory.mergeRunners(Executors.newSingleThreadExecutor(),
+		    factory.mergeRunners(executorService,
-                    Iterables.transform(chiefsOfDataSource, new Function<FireChief, QueryRunner<T>>() {
+		        Iterables.transform(chiefsOfDataSource, new Function<FireChief, QueryRunner<T>>()
+		        {
 			        @Override
-                        public QueryRunner<T> apply(FireChief input) {
+			        public QueryRunner<T> apply(FireChief input)
+			        {
 				        return input.getQueryRunner(query);
-                        }})));
+			        }
+		        })));
 	}
 
   private <T> String getDataSourceName(Query<T> query)

server/src/test/java/io/druid/segment/realtime/RealtimeManagerTest.java

@@ -118,6 +118,7 @@ public class RealtimeManagerTest
                 tuningConfig
             )
         ),
+        null,
         null
     );
   }