fix according to code review

client/src/main/java/com/metamx/druid/client/CachingClusteredClient.java

@@ -125,25 +125,21 @@ public class CachingClusteredClient<T> implements QueryRunner<T>
     final boolean populateCache = Boolean.parseBoolean(query.getContextValue("populateCache", "true"))
                                   && strategy != null;
     final boolean isBySegment = Boolean.parseBoolean(query.getContextValue("bySegment", "false"));
-    final String priority = query.getContextValue("priority", Queries.Priority.NORMAL.name());
 
-    final Query<T> prioritizedQuery = query.withOverriddenContext(ImmutableMap.of("priority", priority));
 
-    final Query<T> rewrittenQuery;
+    ImmutableMap.Builder<String, String> contextBuilder = new ImmutableMap.Builder<String, String>();
+
+    final String priority = query.getContextValue("priority", "0");
+    contextBuilder.put("priority", priority);
+
     if (populateCache) {
-      rewrittenQuery = prioritizedQuery.withOverriddenContext(
+      contextBuilder.put("bySegment", "true");
-          ImmutableMap.of(
-              "bySegment",
-              "true",
-              "intermediate",
-              "true"
-          )
-      );
-    } else {
-      rewrittenQuery = prioritizedQuery.withOverriddenContext(ImmutableMap.of("intermediate", "true"));
     }
+    contextBuilder.put("intermediate", "true");
 
-    VersionedIntervalTimeline<String, ServerSelector> timeline = serverView.getTimeline(prioritizedQuery.getDataSource());
+    final Query<T> rewrittenQuery = query.withOverriddenContext(contextBuilder.build());
+
+    VersionedIntervalTimeline<String, ServerSelector> timeline = serverView.getTimeline(query.getDataSource());
     if (timeline == null) {
       return Sequences.empty();
     }
@@ -159,7 +155,7 @@ public class CachingClusteredClient<T> implements QueryRunner<T>
 
     // Let tool chest filter out unneeded segments
     final List<TimelineObjectHolder<String, ServerSelector>> filteredServersLookup =
-        toolChest.filterSegments(prioritizedQuery, serversLookup);
+        toolChest.filterSegments(query, serversLookup);
 
     for (TimelineObjectHolder<String, ServerSelector> holder : filteredServersLookup) {
       for (PartitionChunk<ServerSelector> chunk : holder.getObject()) {
@@ -174,7 +170,7 @@ public class CachingClusteredClient<T> implements QueryRunner<T>
 
     final byte[] queryCacheKey;
     if (strategy != null) {
-      queryCacheKey = strategy.computeCacheKey(prioritizedQuery);
+      queryCacheKey = strategy.computeCacheKey(query);
     } else {
       queryCacheKey = null;
     }

client/src/main/java/com/metamx/druid/query/ChainedExecutionQueryRunner.java

@@ -24,6 +24,7 @@ import com.google.common.base.Throwables;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Ordering;
+import com.google.common.primitives.Ints;
 import com.metamx.common.guava.BaseSequence;
 import com.metamx.common.guava.MergeIterable;
 import com.metamx.common.guava.Sequence;
@@ -82,6 +83,7 @@ public class ChainedExecutionQueryRunner<T> implements QueryRunner<T>
   @Override
   public Sequence<T> run(final Query<T> query)
   {
+    final int priority = Ints.tryParse(query.getContextValue("priority", "0"));
     return new BaseSequence<T, Iterator<T>>(
         new BaseSequence.IteratorMaker<T, Iterator<T>>()
         {
@@ -103,12 +105,7 @@ public class ChainedExecutionQueryRunner<T> implements QueryRunner<T>
                               @Override
                               public int getPriority()
                               {
-                                return Queries.Priority.valueOf(
+                                return priority;
-                                    query.getContextValue(
-                                        "priority",
-                                        Queries.Priority.NORMAL.name()
-                                    )
-                                ).ordinal();
                               }
 
                               @Override

client/src/main/java/com/metamx/druid/query/PrioritizedExecutorService.java

@@ -36,11 +36,11 @@ import java.util.concurrent.TimeUnit;
 
 /**
  */
-public class PriorityExecutorService extends AbstractExecutorService
+public class PrioritizedExecutorService extends AbstractExecutorService
 {
   public static ExecutorService create(Lifecycle lifecycle, ExecutorServiceConfig config)
   {
-    final ExecutorService service = new PriorityExecutorService(
+    final ExecutorService service = new PrioritizedExecutorService(
         new ThreadPoolExecutor(
             config.getNumThreads(),
             config.getNumThreads(),
@@ -69,10 +69,12 @@ public class PriorityExecutorService extends AbstractExecutorService
 
     return service;
   }
+  private static final int DEFAULT_PRIORITY = 0;
+
 
   private final ThreadPoolExecutor threadPoolExecutor;
 
-  public PriorityExecutorService(
+  public PrioritizedExecutorService(
       ThreadPoolExecutor threadPoolExecutor
   )
   {
@@ -125,7 +127,7 @@ public class PriorityExecutorService extends AbstractExecutorService
         @Override
         public int getPriority()
         {
-          return Queries.Priority.NORMAL.ordinal();
+          return DEFAULT_PRIORITY;
         }
 
         @Override
@@ -156,7 +158,7 @@ public class PriorityExecutorService extends AbstractExecutorService
     @Override
     public int compareTo(PrioritizedFuture future)
     {
-      return Ints.compare(getPriority(), future.getPriority());
+      return -Ints.compare(getPriority(), future.getPriority());
     }
   }
 }

client/src/main/java/com/metamx/druid/query/Queries.java

@@ -34,11 +34,6 @@ import java.util.Set;
  */
 public class Queries
 {
-  public static enum Priority
-  {
-    HIGH, NORMAL, LOW
-  }
-
   public static void verifyAggregations(
       List<AggregatorFactory> aggFactories,
       List<PostAggregator> postAggs

client/src/test/java/com/metamx/druid/query/PrioritizedExecutorServiceTest.java

@@ -19,7 +19,7 @@
 
 package com.metamx.druid.query;
 
-import com.google.common.collect.Lists;
+import com.google.common.collect.ImmutableList;
 import com.metamx.common.concurrent.ExecutorServiceConfig;
 import com.metamx.common.lifecycle.Lifecycle;
 import junit.framework.Assert;
@@ -33,7 +33,7 @@ import java.util.concurrent.ExecutorService;
 
 /**
  */
-public class PriorityExecutorServiceTest
+public class PrioritizedExecutorServiceTest
 {
   private ExecutorService exec;
   private CountDownLatch latch;
@@ -42,7 +42,7 @@ public class PriorityExecutorServiceTest
   @Before
   public void setUp() throws Exception
   {
-    exec = PriorityExecutorService.create(
+    exec = PrioritizedExecutorService.create(
         new Lifecycle(),
         new ExecutorServiceConfig()
         {
@@ -73,7 +73,7 @@ public class PriorityExecutorServiceTest
   @Test
   public void testSubmit() throws Exception
   {
-    final ConcurrentLinkedQueue<Queries.Priority> order = new ConcurrentLinkedQueue<Queries.Priority>();
+    final ConcurrentLinkedQueue<Integer> order = new ConcurrentLinkedQueue<Integer>();
 
     exec.submit(
         new PrioritizedCallable<Void>()
@@ -81,7 +81,7 @@ public class PriorityExecutorServiceTest
           @Override
           public int getPriority()
           {
-            return Queries.Priority.NORMAL.ordinal();
+            return 0;
           }
 
           @Override
@@ -99,13 +99,13 @@ public class PriorityExecutorServiceTest
           @Override
           public int getPriority()
           {
-            return Queries.Priority.LOW.ordinal();
+            return -1;
           }
 
           @Override
           public Void call() throws Exception
           {
-            order.add(Queries.Priority.LOW);
+            order.add(-1);
             finishLatch.countDown();
             return null;
           }
@@ -117,13 +117,13 @@ public class PriorityExecutorServiceTest
           @Override
           public int getPriority()
           {
-            return Queries.Priority.HIGH.ordinal();
+            return 0;
           }
 
           @Override
           public Void call() throws Exception
           {
-            order.add(Queries.Priority.HIGH);
+            order.add(0);
             finishLatch.countDown();
             return null;
           }
@@ -135,13 +135,13 @@ public class PriorityExecutorServiceTest
           @Override
           public int getPriority()
           {
-            return Queries.Priority.NORMAL.ordinal();
+            return 2;
           }
 
           @Override
           public Void call() throws Exception
           {
-            order.add(Queries.Priority.NORMAL);
+            order.add(2);
             finishLatch.countDown();
             return null;
           }
@@ -153,16 +153,7 @@ public class PriorityExecutorServiceTest
 
     Assert.assertTrue(order.size() == 3);
 
-    List<Queries.Priority> expected = Lists.newArrayList(
+    List<Integer> expected = ImmutableList.of(2, 0, -1);
-        Queries.Priority.HIGH,
+    Assert.assertEquals(expected, ImmutableList.copyOf(order));
-        Queries.Priority.NORMAL,
-        Queries.Priority.LOW
-    );
-
-    int i = 0;
-    for (Queries.Priority priority : order) {
-      Assert.assertEquals(expected.get(i), priority);
-      i++;
-    }
   }
 }

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

@@ -39,7 +39,7 @@ import com.metamx.druid.jackson.DefaultObjectMapper;
 import com.metamx.druid.loading.SegmentLoader;
 import com.metamx.druid.metrics.ServerMonitor;
 import com.metamx.druid.query.MetricsEmittingExecutorService;
-import com.metamx.druid.query.PriorityExecutorService;
+import com.metamx.druid.query.PrioritizedExecutorService;
 import com.metamx.druid.query.QueryRunnerFactoryConglomerate;
 import com.metamx.emitter.service.ServiceEmitter;
 import com.metamx.emitter.service.ServiceMetricEvent;
@@ -97,11 +97,11 @@ public class ComputeNode extends BaseServerNode<ComputeNode>
     final List<Monitor> monitors = getMonitors();
     final QueryRunnerFactoryConglomerate conglomerate = getConglomerate();
 
-    final ExecutorService innerExecutorService = PriorityExecutorService.create(
+    final ExecutorService innerExecutorService = PrioritizedExecutorService.create(
         getLifecycle(),
         getConfigFactory().buildWithReplacements(
             ExecutorServiceConfig.class, ImmutableMap.of("base_path", "druid.processing")
-        )
+        ), callable2
     );
 
     final ExecutorService executorService = new MetricsEmittingExecutorService(