use num processing threads for realtime query execution

realtime/src/main/java/com/metamx/druid/realtime/RealtimeNode.java

@@ -189,6 +189,7 @@ public class RealtimeNode extends BaseServerNode<RealtimeNode>
     injectables.put("segmentPublisher", getSegmentPublisher());
     injectables.put("serverView", getServerView());
     injectables.put("serviceEmitter", getEmitter());
+    injectables.put("queryExecutorService", getQueryExecutorService());
 
     getJsonMapper().setInjectableValues(
         new InjectableValues()

realtime/src/main/java/com/metamx/druid/realtime/plumber/RealtimePlumberSchool.java

@@ -25,7 +25,6 @@ import com.fasterxml.jackson.annotation.JsonProperty;
 import com.google.common.base.Function;
 import com.google.common.base.Joiner;
 import com.google.common.base.Preconditions;
-import com.google.common.base.Predicates;
 import com.google.common.base.Throwables;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
@@ -92,7 +91,6 @@ import java.util.concurrent.ScheduledExecutorService;
 public class RealtimePlumberSchool implements PlumberSchool
 {
   private static final EmittingLogger log = new EmittingLogger(RealtimePlumberSchool.class);
-  private static final ListeningExecutorService EXEC = MoreExecutors.sameThreadExecutor();
 
   private final Period windowPeriod;
   private final File basePersistDirectory;
@@ -108,6 +106,7 @@ public class RealtimePlumberSchool implements PlumberSchool
   private volatile DataSegmentAnnouncer segmentAnnouncer = null;
   private volatile SegmentPublisher segmentPublisher = null;
   private volatile ServerView serverView = null;
+  private volatile ExecutorService queryExecutorService = null;
 
   @JsonCreator
   public RealtimePlumberSchool(
@@ -175,6 +174,12 @@ public class RealtimePlumberSchool implements PlumberSchool
     this.emitter = emitter;
   }
 
+  @JacksonInject("queryExecutorService")
+  public void setQueryExecutorService(ExecutorService queryExecutorService)
+  {
+    this.queryExecutorService = queryExecutorService;
+  }
+
   @Override
   public Plumber findPlumber(final Schema schema, final FireDepartmentMetrics metrics)
   {
@@ -262,7 +267,7 @@ public class RealtimePlumberSchool implements PlumberSchool
 
         return toolchest.mergeResults(
             factory.mergeRunners(
-                EXEC,
+                queryExecutorService,
                 FunctionalIterable
                     .create(querySinks)
                     .transform(
@@ -277,7 +282,7 @@ public class RealtimePlumberSchool implements PlumberSchool
                                     emitter,
                                     builderFn,
                                     factory.mergeRunners(
-                                        EXEC,
+                                        MoreExecutors.sameThreadExecutor(),
                                         Iterables.transform(
                                             theSink,
                                             new Function<FireHydrant, QueryRunner<T>>()

server/src/main/java/com/metamx/druid/BaseServerNode.java

@@ -23,19 +23,24 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Maps;
+import com.metamx.common.concurrent.ExecutorServiceConfig;
 import com.metamx.common.lifecycle.Lifecycle;
 import com.metamx.common.logger.Logger;
 import com.metamx.druid.collect.StupidPool;
 import com.metamx.druid.initialization.ServerInit;
 import com.metamx.druid.query.DefaultQueryRunnerFactoryConglomerate;
+import com.metamx.druid.query.MetricsEmittingExecutorService;
+import com.metamx.druid.query.PrioritizedExecutorService;
 import com.metamx.druid.query.QueryRunnerFactory;
 import com.metamx.druid.query.QueryRunnerFactoryConglomerate;
 
+import com.metamx.emitter.service.ServiceMetricEvent;
 import org.skife.config.ConfigurationObjectFactory;
 
 import java.nio.ByteBuffer;
 import java.util.Map;
 import java.util.Properties;
+import java.util.concurrent.ExecutorService;
 
 /**
  */
@@ -45,6 +50,7 @@ public abstract class BaseServerNode<T extends QueryableNode> extends QueryableN
   private DruidProcessingConfig processingConfig = null;
   private QueryRunnerFactoryConglomerate conglomerate = null;
   private StupidPool<ByteBuffer> computeScratchPool = null;
+  private ExecutorService queryExecutorService = null;
 
   public BaseServerNode(
       String nodeType,
@@ -77,6 +83,12 @@ public abstract class BaseServerNode<T extends QueryableNode> extends QueryableN
     return processingConfig;
   }
 
+  public ExecutorService getQueryExecutorService()
+  {
+    initializeQueryExecutorService();
+    return queryExecutorService;
+  }
+
   @SuppressWarnings("unchecked")
   public T setConglomerate(QueryRunnerFactoryConglomerate conglomerate)
   {
@@ -98,6 +110,13 @@ public abstract class BaseServerNode<T extends QueryableNode> extends QueryableN
     return (T) this;
   }
 
+  @SuppressWarnings("unchecked")
+  public T setQueryExecutorService(ExecutorService queryExecutorService)
+  {
+    checkFieldNotSetAndSet("queryExecutorService", queryExecutorService);
+    return (T) this;
+  }
+
   @SuppressWarnings("unchecked")
   public T registerQueryRunnerFactory(Class<? extends Query> queryClazz, QueryRunnerFactory factory)
   {
@@ -144,4 +163,24 @@ public abstract class BaseServerNode<T extends QueryableNode> extends QueryableN
       );
     }
   }
+
+  private void initializeQueryExecutorService()
+  {
+    if (queryExecutorService == null) {
+      final PrioritizedExecutorService innerExecutorService = PrioritizedExecutorService.create(
+          getLifecycle(),
+          getConfigFactory().buildWithReplacements(
+              ExecutorServiceConfig.class, ImmutableMap.of("base_path", "druid.processing")
+          )
+      );
+
+      setQueryExecutorService(
+          new MetricsEmittingExecutorService(
+              innerExecutorService,
+              getEmitter(),
+              new ServiceMetricEvent.Builder()
+          )
+      );
+    }
+  }
 }

server/src/main/java/com/metamx/druid/http/ComputeNode.java

@@ -97,21 +97,13 @@ public class ComputeNode extends BaseServerNode<ComputeNode>
     final List<Monitor> monitors = getMonitors();
     final QueryRunnerFactoryConglomerate conglomerate = getConglomerate();
 
-    final PrioritizedExecutorService innerExecutorService = PrioritizedExecutorService.create(
-        getLifecycle(),
-        getConfigFactory().buildWithReplacements(
-            ExecutorServiceConfig.class, ImmutableMap.of("base_path", "druid.processing")
-        )
-    );
-
-    final ExecutorService executorService = new MetricsEmittingExecutorService(
-        innerExecutorService,
+    final ServerManager serverManager = new ServerManager(
+        getSegmentLoader(),
+        conglomerate,
         emitter,
-        new ServiceMetricEvent.Builder()
+        getQueryExecutorService()
     );
 
-    final ServerManager serverManager = new ServerManager(getSegmentLoader(), conglomerate, emitter, executorService);
-
     final ZkCoordinator coordinator = new ZkCoordinator(
         getJsonMapper(),
         getConfigFactory().build(ZkCoordinatorConfig.class),
@@ -206,5 +198,4 @@ public class ComputeNode extends BaseServerNode<ComputeNode>
       return new ComputeNode(props, lifecycle, jsonMapper, smileMapper, configFactory);
     }
   }
-
-}
+}