diff --git a/processing/src/main/java/io/druid/query/AbstractPrioritizedCallable.java b/processing/src/main/java/io/druid/query/AbstractPrioritizedCallable.java
new file mode 100644
index 00000000000..e3371d1210f
--- /dev/null
+++ b/processing/src/main/java/io/druid/query/AbstractPrioritizedCallable.java
@@ -0,0 +1,36 @@
+/*
+ * Druid - a distributed column store.
+ * Copyright (C) 2012, 2013, 2014  Metamarkets Group Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+package io.druid.query;
+
+public abstract class AbstractPrioritizedCallable<V> implements PrioritizedCallable<V>
+{
+  private final int priority;
+
+  public AbstractPrioritizedCallable(int priority)
+  {
+    this.priority = priority;
+  }
+
+  @Override
+  public int getPriority()
+  {
+    return priority;
+  }
+}
diff --git a/processing/src/main/java/io/druid/query/ChainedExecutionQueryRunner.java b/processing/src/main/java/io/druid/query/ChainedExecutionQueryRunner.java
index 6d7d1ea25b5..31eac12702e 100644
--- a/processing/src/main/java/io/druid/query/ChainedExecutionQueryRunner.java
+++ b/processing/src/main/java/io/druid/query/ChainedExecutionQueryRunner.java
@@ -103,7 +103,7 @@ public class ChainedExecutionQueryRunner<T> implements QueryRunner<T>
                       public Future<List<T>> apply(final QueryRunner<T> input)
                       {
                         return exec.submit(
-                            new PrioritizedCallable<List<T>>(priority)
+                            new AbstractPrioritizedCallable<List<T>>(priority)
                             {
                               @Override
                               public List<T> call() throws Exception
diff --git a/processing/src/main/java/io/druid/query/DelegatingExecutorService.java b/processing/src/main/java/io/druid/query/DelegatingExecutorService.java
deleted file mode 100644
index 5a6be3f854c..00000000000
--- a/processing/src/main/java/io/druid/query/DelegatingExecutorService.java
+++ /dev/null
@@ -1,127 +0,0 @@
-/*
- * Druid - a distributed column store.
- * Copyright (C) 2012, 2013  Metamarkets Group Inc.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
- */
-
-package io.druid.query;
-
-import java.util.Collection;
-import java.util.List;
-import java.util.concurrent.Callable;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Future;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;
-
-/**
- */
-public class DelegatingExecutorService implements ExecutorService
-{
-  private final ExecutorService delegate;
-
-  public DelegatingExecutorService(ExecutorService delegate)
-  {
-    this.delegate = delegate;
-  }
-
-  @Override
-  public void shutdown()
-  {
-    delegate.shutdown();
-  }
-
-  @Override
-  public List<Runnable> shutdownNow()
-  {
-    return delegate.shutdownNow();
-  }
-
-  @Override
-  public boolean isShutdown()
-  {
-    return delegate.isShutdown();
-  }
-
-  @Override
-  public boolean isTerminated()
-  {
-    return delegate.isTerminated();
-  }
-
-  @Override
-  public boolean awaitTermination(long l, TimeUnit timeUnit) throws InterruptedException
-  {
-    return delegate.awaitTermination(l, timeUnit);
-  }
-
-  @Override
-  public <T> Future<T> submit(Callable<T> tCallable)
-  {
-    return delegate.submit(tCallable);
-  }
-
-  @Override
-  public <T> Future<T> submit(Runnable runnable, T t)
-  {
-    return delegate.submit(runnable, t);
-  }
-
-  @Override
-  public Future<?> submit(Runnable runnable)
-  {
-    return delegate.submit(runnable);
-  }
-
-  @Override
-  public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> callables) throws InterruptedException
-  {
-    return delegate.invokeAll(callables);
-  }
-
-  @Override
-  public <T> List<Future<T>> invokeAll(
-      Collection<? extends Callable<T>> callables,
-      long l,
-      TimeUnit timeUnit
-  ) throws InterruptedException
-  {
-    return delegate.invokeAll(callables, l, timeUnit);
-  }
-
-  @Override
-  public <T> T invokeAny(Collection<? extends Callable<T>> callables) throws InterruptedException, ExecutionException
-  {
-    return delegate.invokeAny(callables);
-  }
-
-  @Override
-  public <T> T invokeAny(
-      Collection<? extends Callable<T>> callables,
-      long l,
-      TimeUnit timeUnit
-  ) throws InterruptedException, ExecutionException, TimeoutException
-  {
-    return delegate.invokeAny(callables, l, timeUnit);
-  }
-
-  @Override
-  public void execute(Runnable runnable)
-  {
-    delegate.execute(runnable);
-  }
-}
diff --git a/processing/src/main/java/io/druid/query/GroupByParallelQueryRunner.java b/processing/src/main/java/io/druid/query/GroupByParallelQueryRunner.java
index 20817a772e5..51c663c6a2e 100644
--- a/processing/src/main/java/io/druid/query/GroupByParallelQueryRunner.java
+++ b/processing/src/main/java/io/druid/query/GroupByParallelQueryRunner.java
@@ -97,7 +97,7 @@ public class GroupByParallelQueryRunner implements QueryRunner<Row>
               public Future<Boolean> apply(final QueryRunner<Row> input)
               {
                 return exec.submit(
-                    new PrioritizedCallable<Boolean>(priority)
+                    new AbstractPrioritizedCallable<Boolean>(priority)
                     {
                       @Override
                       public Boolean call() throws Exception
diff --git a/processing/src/main/java/io/druid/query/MetricsEmittingExecutorService.java b/processing/src/main/java/io/druid/query/MetricsEmittingExecutorService.java
index 37ed9e81e12..e581e77399d 100644
--- a/processing/src/main/java/io/druid/query/MetricsEmittingExecutorService.java
+++ b/processing/src/main/java/io/druid/query/MetricsEmittingExecutorService.java
@@ -19,51 +19,57 @@
 
 package io.druid.query;
 
+import com.google.common.util.concurrent.ForwardingListeningExecutorService;
+import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.ListeningExecutorService;
 import com.metamx.emitter.service.ServiceEmitter;
 import com.metamx.emitter.service.ServiceMetricEvent;
 
 import java.util.concurrent.Callable;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Future;
-import java.util.concurrent.ThreadPoolExecutor;
 
-public class MetricsEmittingExecutorService extends DelegatingExecutorService
+public class MetricsEmittingExecutorService extends ForwardingListeningExecutorService
 {
-  private final ExecutorService base;
+  private final ListeningExecutorService delegate;
   private final ServiceEmitter emitter;
   private final ServiceMetricEvent.Builder metricBuilder;
 
   public MetricsEmittingExecutorService(
-      ExecutorService base,
+      ListeningExecutorService delegate,
       ServiceEmitter emitter,
       ServiceMetricEvent.Builder metricBuilder
   )
   {
-    super(base);
+    super();
 
-    this.base = base;
+    this.delegate = delegate;
     this.emitter = emitter;
     this.metricBuilder = metricBuilder;
   }
 
   @Override
-  public <T> Future<T> submit(Callable<T> tCallable)
+  protected ListeningExecutorService delegate()
+  {
+    return delegate;
+  }
+
+  @Override
+  public <T> ListenableFuture<T> submit(Callable<T> tCallable)
   {
     emitMetrics();
-    return base.submit(tCallable);
+    return delegate.submit(tCallable);
   }
 
   @Override
   public void execute(Runnable runnable)
   {
     emitMetrics();
-    base.execute(runnable);
+    delegate.execute(runnable);
   }
 
   private void emitMetrics()
   {
-    if (base instanceof PrioritizedExecutorService) {
-      emitter.emit(metricBuilder.build("exec/backlog", ((PrioritizedExecutorService) base).getQueueSize()));
+    if (delegate instanceof PrioritizedExecutorService) {
+      emitter.emit(metricBuilder.build("exec/backlog", ((PrioritizedExecutorService) delegate).getQueueSize()));
     }
   }
 }
diff --git a/processing/src/main/java/io/druid/query/PrioritizedCallable.java b/processing/src/main/java/io/druid/query/PrioritizedCallable.java
index e664a8d682b..fb61da9f70c 100644
--- a/processing/src/main/java/io/druid/query/PrioritizedCallable.java
+++ b/processing/src/main/java/io/druid/query/PrioritizedCallable.java
@@ -21,19 +21,7 @@ package io.druid.query;
 
 import java.util.concurrent.Callable;
 
-/**
- */
-public abstract class PrioritizedCallable<T> implements Callable<T>
+public interface PrioritizedCallable<V> extends Callable<V>
 {
-  final int priority;
-
-  public PrioritizedCallable(int priority)
-  {
-    this.priority = priority;
-  }
-
-  public int getPriority()
-  {
-    return priority;
-  }
+  public int getPriority();
 }
diff --git a/processing/src/main/java/io/druid/query/PrioritizedExecutorService.java b/processing/src/main/java/io/druid/query/PrioritizedExecutorService.java
index 95f465a4edf..c0dd98b6718 100644
--- a/processing/src/main/java/io/druid/query/PrioritizedExecutorService.java
+++ b/processing/src/main/java/io/druid/query/PrioritizedExecutorService.java
@@ -19,23 +19,30 @@
 
 package io.druid.query;
 
+import com.google.common.base.Preconditions;
 import com.google.common.primitives.Ints;
+import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.ListenableFutureTask;
+import com.google.common.util.concurrent.ListeningExecutorService;
+import com.google.common.util.concurrent.MoreExecutors;
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
 import com.metamx.common.concurrent.ExecutorServiceConfig;
 import com.metamx.common.lifecycle.Lifecycle;
 
+import javax.annotation.Nullable;
 import java.util.List;
 import java.util.concurrent.AbstractExecutorService;
+import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.Callable;
-import java.util.concurrent.FutureTask;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executor;
 import java.util.concurrent.PriorityBlockingQueue;
 import java.util.concurrent.RunnableFuture;
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
 
-/**
- */
-public class PrioritizedExecutorService extends AbstractExecutorService
+public class PrioritizedExecutorService extends AbstractExecutorService implements ListeningExecutorService
 {
   public static PrioritizedExecutorService create(Lifecycle lifecycle, ExecutorServiceConfig config)
   {
@@ -69,95 +76,180 @@ public class PrioritizedExecutorService extends AbstractExecutorService
     return service;
   }
 
-  private static final int DEFAULT_PRIORITY = 0;
-
-
-  private final ThreadPoolExecutor threadPoolExecutor;
+  private final ListeningExecutorService delegate;
+  private final BlockingQueue<Runnable> delegateQueue;
+  private final boolean allowRegularTasks;
+  private final int defaultPriority;
 
   public PrioritizedExecutorService(
       ThreadPoolExecutor threadPoolExecutor
   )
   {
-    this.threadPoolExecutor = threadPoolExecutor;
+    this(threadPoolExecutor, false, 0);
+  }
+
+  public PrioritizedExecutorService(
+      ThreadPoolExecutor threadPoolExecutor,
+      boolean allowRegularTasks,
+      int defaultPriority
+  )
+  {
+    this.delegate = MoreExecutors.listeningDecorator(Preconditions.checkNotNull(threadPoolExecutor));
+    this.delegateQueue = threadPoolExecutor.getQueue();
+    this.allowRegularTasks = allowRegularTasks;
+    this.defaultPriority = defaultPriority;
+  }
+
+  @Override protected <T> PrioritizedListenableFutureTask<T> newTaskFor(Runnable runnable, T value) {
+    Preconditions.checkArgument(allowRegularTasks || runnable instanceof PrioritizedRunnable, "task does not implement PrioritizedRunnable");
+    return PrioritizedListenableFutureTask.create(ListenableFutureTask.create(runnable, value),
+                                                  runnable instanceof PrioritizedRunnable
+                                                  ? ((PrioritizedRunnable) runnable).getPriority()
+                                                  : defaultPriority
+    );
+  }
+
+  @Override protected <T> PrioritizedListenableFutureTask<T> newTaskFor(Callable<T> callable) {
+    Preconditions.checkArgument(allowRegularTasks || callable instanceof PrioritizedCallable, "task does not implement PrioritizedCallable");
+    return PrioritizedListenableFutureTask.create(
+        ListenableFutureTask.create(callable), callable instanceof PrioritizedCallable
+                                               ? ((PrioritizedCallable) callable).getPriority()
+                                               : defaultPriority
+    );
+  }
+
+  @Override public ListenableFuture<?> submit(Runnable task) {
+    return (ListenableFuture<?>) super.submit(task);
+  }
+
+  @Override public <T> ListenableFuture<T> submit(Runnable task, @Nullable T result) {
+    return (ListenableFuture<T>) super.submit(task, result);
+  }
+
+  @Override public <T> ListenableFuture<T> submit(Callable<T> task) {
+    return (ListenableFuture<T>) super.submit(task);
   }
 
   @Override
   public void shutdown()
   {
-    threadPoolExecutor.shutdown();
+    delegate.shutdown();
   }
 
   @Override
   public List<Runnable> shutdownNow()
   {
-    return threadPoolExecutor.shutdownNow();
+    return delegate.shutdownNow();
   }
 
   @Override
   public boolean isShutdown()
   {
-    return threadPoolExecutor.isShutdown();
+    return delegate.isShutdown();
   }
 
   @Override
   public boolean isTerminated()
   {
-    return threadPoolExecutor.isTerminated();
+    return delegate.isTerminated();
   }
 
   @Override
   public boolean awaitTermination(long l, TimeUnit timeUnit) throws InterruptedException
   {
-    return threadPoolExecutor.awaitTermination(l, timeUnit);
+    return delegate.awaitTermination(l, timeUnit);
   }
 
   @Override
-  public void execute(Runnable runnable)
+  public void execute(final Runnable runnable)
   {
-    threadPoolExecutor.execute(runnable);
-  }
-
-  @Override
-  protected <T> RunnableFuture<T> newTaskFor(final Callable<T> tCallable)
-  {
-    Callable<T> theCallable = tCallable;
-    if (!(tCallable instanceof PrioritizedCallable)) {
-      theCallable = new PrioritizedCallable<T>(DEFAULT_PRIORITY)
-      {
-        @Override
-        public T call() throws Exception
-        {
-          return tCallable.call();
-        }
-      };
-    }
-    return new PrioritizedFuture<T>((PrioritizedCallable) theCallable);
+    delegate.execute(runnable);
   }
 
   public int getQueueSize()
   {
-    return threadPoolExecutor.getQueue().size();
+    return delegateQueue.size();
   }
 
-  private static class PrioritizedFuture<V> extends FutureTask<V> implements Comparable<PrioritizedFuture>
-  {
-    private final PrioritizedCallable<V> callable;
 
-    public PrioritizedFuture(PrioritizedCallable<V> callable)
+  public static class PrioritizedListenableFutureTask<V> implements RunnableFuture<V>, ListenableFuture<V>, PrioritizedRunnable, Comparable<PrioritizedListenableFutureTask>
+  {
+    public static <V> PrioritizedListenableFutureTask<V> create(PrioritizedRunnable task, @Nullable V result)
     {
-      super(callable);
-      this.callable = callable;
+      return new PrioritizedListenableFutureTask<>(ListenableFutureTask.create(task, result), task.getPriority());
     }
 
-    public int getPriority()
+    public static <V> PrioritizedListenableFutureTask<?> create(PrioritizedCallable<V> callable)
     {
-      return callable.getPriority();
+      return new PrioritizedListenableFutureTask<>(ListenableFutureTask.create(callable), callable.getPriority());
+    }
+
+    public static <V> PrioritizedListenableFutureTask<V> create(ListenableFutureTask<V> task, int priority)
+    {
+      return new PrioritizedListenableFutureTask<>(task, priority);
+    }
+
+    private final ListenableFutureTask<V> delegate;
+    private final int priority;
+
+    PrioritizedListenableFutureTask(ListenableFutureTask<V> delegate, int priority)
+    {
+      this.delegate = delegate;
+      this.priority = priority;
     }
 
     @Override
-    public int compareTo(PrioritizedFuture future)
+    public void run()
     {
-      return -Ints.compare(getPriority(), future.getPriority());
+      delegate.run();
+    }
+
+    @Override
+    public boolean cancel(boolean mayInterruptIfRunning)
+    {
+      return delegate.cancel(mayInterruptIfRunning);
+    }
+
+    @Override
+    public boolean isCancelled()
+    {
+      return delegate.isCancelled();
+    }
+
+    @Override
+    public boolean isDone()
+    {
+      return delegate.isDone();
+    }
+
+    @Override
+    public V get() throws InterruptedException, ExecutionException
+    {
+      return delegate.get();
+    }
+
+    @Override
+    public V get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException
+    {
+      return delegate.get(timeout, unit);
+    }
+
+    @Override
+    public void addListener(Runnable listener, Executor executor)
+    {
+      delegate.addListener(listener, executor);
+    }
+
+    @Override
+    public int getPriority()
+    {
+      return priority;
+    }
+
+    @Override
+    public int compareTo(PrioritizedListenableFutureTask otherTask)
+    {
+      return -Ints.compare(getPriority(), otherTask.getPriority());
     }
   }
 }
diff --git a/processing/src/main/java/io/druid/query/PrioritizedRunnable.java b/processing/src/main/java/io/druid/query/PrioritizedRunnable.java
new file mode 100644
index 00000000000..6e277b20423
--- /dev/null
+++ b/processing/src/main/java/io/druid/query/PrioritizedRunnable.java
@@ -0,0 +1,25 @@
+/*
+ * Druid - a distributed column store.
+ * Copyright (C) 2012, 2013, 2014  Metamarkets Group Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+package io.druid.query;
+
+public interface PrioritizedRunnable extends Runnable
+{
+  public int getPriority();
+}
diff --git a/processing/src/test/java/io/druid/query/PrioritizedExecutorServiceTest.java b/processing/src/test/java/io/druid/query/PrioritizedExecutorServiceTest.java
index 0209fafa5ec..1d6f8a2ae07 100644
--- a/processing/src/test/java/io/druid/query/PrioritizedExecutorServiceTest.java
+++ b/processing/src/test/java/io/druid/query/PrioritizedExecutorServiceTest.java
@@ -27,6 +27,7 @@ import org.junit.Before;
 import org.junit.Test;
 
 import java.util.List;
+import java.util.concurrent.Callable;
 import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutorService;
@@ -76,7 +77,7 @@ public class PrioritizedExecutorServiceTest
     final ConcurrentLinkedQueue<Integer> order = new ConcurrentLinkedQueue<Integer>();
 
     exec.submit(
-        new PrioritizedCallable<Void>(0)
+        new AbstractPrioritizedCallable<Void>(0)
         {
           @Override
           public Void call() throws Exception
@@ -88,7 +89,7 @@ public class PrioritizedExecutorServiceTest
     );
 
     exec.submit(
-        new PrioritizedCallable<Void>(-1)
+        new AbstractPrioritizedCallable<Void>(-1)
         {
           @Override
           public Void call() throws Exception
@@ -100,7 +101,7 @@ public class PrioritizedExecutorServiceTest
         }
     );
     exec.submit(
-        new PrioritizedCallable<Void>(0)
+        new AbstractPrioritizedCallable<Void>(0)
         {
           @Override
           public Void call() throws Exception
@@ -112,7 +113,7 @@ public class PrioritizedExecutorServiceTest
         }
     );
     exec.submit(
-        new PrioritizedCallable<Void>(2)
+        new AbstractPrioritizedCallable<Void>(2)
         {
           @Override
           public Void call() throws Exception