Fix a couple of bugs with retry query runner after testing it locally

processing/src/main/java/io/druid/query/RetryQueryRunner.java

@@ -27,6 +27,7 @@ import com.metamx.common.guava.Sequence;
 import com.metamx.common.guava.Yielder;
 import com.metamx.common.guava.YieldingAccumulator;
 import com.metamx.common.guava.YieldingSequenceBase;
+import com.metamx.emitter.EmittingLogger;
 import io.druid.query.spec.MultipleSpecificSegmentSpec;
 import io.druid.segment.SegmentMissingException;
 
@@ -36,6 +37,7 @@ import java.util.Map;
 public class RetryQueryRunner<T> implements QueryRunner<T>
 {
   public static String MISSING_SEGMENTS_KEY = "missingSegments";
+  private static final EmittingLogger log = new EmittingLogger(RetryQueryRunner.class);
 
   private final QueryRunner<T> baseRunner;
   private final RetryQueryRunnerConfig config;
@@ -73,6 +75,8 @@ public class RetryQueryRunner<T> implements QueryRunner<T>
         }
 
         for (int i = 0; i < config.numTries(); i++) {
+          log.info("[%,d] missing segments found. Retry attempt [%,d]", missingSegments.size(), i);
+
           context.put(MISSING_SEGMENTS_KEY, Lists.newArrayList());
           final Query<T> retryQuery = query.withQuerySegmentSpec(
               new MultipleSpecificSegmentSpec(

processing/src/main/java/io/druid/query/spec/SpecificSegmentQueryRunner.java

@@ -23,7 +23,6 @@ import com.google.common.base.Throwables;
 import com.google.common.collect.Lists;
 import com.metamx.common.guava.Accumulator;
 import com.metamx.common.guava.Sequence;
-import com.metamx.common.guava.Sequences;
 import com.metamx.common.guava.Yielder;
 import com.metamx.common.guava.YieldingAccumulator;
 import io.druid.query.Query;
@@ -68,20 +67,7 @@ public class SpecificSegmentQueryRunner<T> implements QueryRunner<T>
           @Override
           public Sequence<T> call() throws Exception
           {
-            Sequence<T> returningSeq;
+            return base.run(query, context);
-            try {
-              returningSeq = base.run(query, context);
-            }
-            catch (SegmentMissingException e) {
-              List<SegmentDescriptor> missingSegments = (List<SegmentDescriptor>) context.get(RetryQueryRunner.MISSING_SEGMENTS_KEY);
-              if (missingSegments == null) {
-                missingSegments = Lists.newArrayList();
-                context.put(RetryQueryRunner.MISSING_SEGMENTS_KEY, missingSegments);
-              }
-              missingSegments.add(specificSpec.getDescriptor());
-              returningSeq = Sequences.empty();
-            }
-            return returningSeq;
           }
         }
     );
@@ -97,8 +83,19 @@ public class SpecificSegmentQueryRunner<T> implements QueryRunner<T>
               @Override
               public OutType call() throws Exception
               {
+                try {
                   return baseSequence.accumulate(initValue, accumulator);
                 }
+                catch (SegmentMissingException e) {
+                  List<SegmentDescriptor> missingSegments = (List<SegmentDescriptor>) context.get(RetryQueryRunner.MISSING_SEGMENTS_KEY);
+                  if (missingSegments == null) {
+                    missingSegments = Lists.newArrayList();
+                    context.put(RetryQueryRunner.MISSING_SEGMENTS_KEY, missingSegments);
+                  }
+                  missingSegments.add(specificSpec.getDescriptor());
+                  return initValue;
+                }
+              }
             }
         );
       }

processing/src/main/java/io/druid/query/timeseries/TimeseriesQueryEngine.java

@@ -36,8 +36,6 @@ import java.util.List;
  */
 public class TimeseriesQueryEngine
 {
-  private static final int AGG_UNROLL_COUNT = 8;
-
   public Sequence<Result<TimeseriesResultValue>> process(final TimeseriesQuery query, final StorageAdapter adapter)
   {
     if (adapter == null) {

server/src/main/java/io/druid/server/QueryResource.java

@@ -153,8 +153,8 @@ public class QueryResource
         log.debug("Got query [%s]", query);
       }
 
-      final Map<String, Object> context = new MapMaker().makeMap();
+      final Map<String, Object> responseContext = new MapMaker().makeMap();
-      final Sequence res = query.run(texasRanger, context);
+      final Sequence res = query.run(texasRanger, responseContext);
       final Sequence results;
       if (res == null) {
         results = Sequences.empty();
@@ -212,7 +212,7 @@ public class QueryResource
                 isSmile ? APPLICATION_JSON : APPLICATION_SMILE
             )
             .header("X-Druid-Query-Id", queryId)
-            .header("X-Druid-Response-Context", jsonMapper.writeValueAsString(context))
+            .header("X-Druid-Response-Context", jsonMapper.writeValueAsString(responseContext))
             .build();
       }
       catch (Exception e) {