Don't pass QueryMetrics down in concurrent and async QueryRunners (fixes #4279) (#4288)

* Don't pass QueryMetrics down in concurrent and async QueryRunners

* Rename QueryPlus.threadSafe() to withoutThreadUnsafeState(); Update QueryPlus.withQueryMetrics() Javadocs; Fix generics in MetricsEmittingQueryRunner and CpuTimeMetricQueryRunner; Make DefaultQueryMetrics to fail fast on modifications from concurrent threads

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

@@ -51,6 +51,7 @@ public class AsyncQueryRunner<T> implements QueryRunner<T>
   {
     final Query<T> query = queryPlus.getQuery();
     final int priority = QueryContexts.getPriority(query);
+    final QueryPlus<T> threadSafeQueryPlus = queryPlus.withoutThreadUnsafeState();
     final ListenableFuture<Sequence<T>> future = executor.submit(new AbstractPrioritizedCallable<Sequence<T>>(priority)
         {
           @Override
@@ -58,7 +59,7 @@ public class AsyncQueryRunner<T> implements QueryRunner<T>
           {
             //Note: this is assumed that baseRunner does most of the work eagerly on call to the
             //run() method and resulting sequence accumulate/yield is fast.
-            return baseRunner.run(queryPlus, responseContext);
+            return baseRunner.run(threadSafeQueryPlus, responseContext);
           }
         });
     queryWatcher.registerQuery(query, future);

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

@@ -33,14 +33,14 @@ import java.util.concurrent.atomic.AtomicLong;
 public class CPUTimeMetricQueryRunner<T> implements QueryRunner<T>
 {
   private final QueryRunner<T> delegate;
-  private final QueryToolChest<?, ? super Query<T>> queryToolChest;
+  private final QueryToolChest<T, ? extends Query<T>> queryToolChest;
   private final ServiceEmitter emitter;
   private final AtomicLong cpuTimeAccumulator;
   private final boolean report;
 
   private CPUTimeMetricQueryRunner(
       QueryRunner<T> delegate,
-      QueryToolChest<?, ? super Query<T>> queryToolChest,
+      QueryToolChest<T, ? extends Query<T>> queryToolChest,
       ServiceEmitter emitter,
       AtomicLong cpuTimeAccumulator,
       boolean report
@@ -60,8 +60,7 @@ public class CPUTimeMetricQueryRunner<T> implements QueryRunner<T>
   @Override
   public Sequence<T> run(final QueryPlus<T> queryPlus, final Map<String, Object> responseContext)
   {
-    final QueryPlus<T> queryWithMetrics =
-        queryPlus.withQueryMetrics((QueryToolChest<T, ? extends Query<T>>) queryToolChest);
+    final QueryPlus<T> queryWithMetrics = queryPlus.withQueryMetrics(queryToolChest);
     final Sequence<T> baseSequence = delegate.run(queryWithMetrics, responseContext);
     return Sequences.wrap(
         baseSequence,
@@ -94,7 +93,7 @@ public class CPUTimeMetricQueryRunner<T> implements QueryRunner<T>
 
   public static <T> QueryRunner<T> safeBuild(
       QueryRunner<T> delegate,
-      QueryToolChest<?, ? super Query<T>> queryToolChest,
+      QueryToolChest<T, ? extends Query<T>> queryToolChest,
       ServiceEmitter emitter,
       AtomicLong accumulator,
       boolean report

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

@@ -94,7 +94,7 @@ public class ChainedExecutionQueryRunner<T> implements QueryRunner<T>
     Query<T> query = queryPlus.getQuery();
     final int priority = QueryContexts.getPriority(query);
     final Ordering ordering = query.getResultOrdering();
-
+    final QueryPlus<T> threadSafeQueryPlus = queryPlus.withoutThreadUnsafeState();
     return new BaseSequence<T, Iterator<T>>(
         new BaseSequence.IteratorMaker<T, Iterator<T>>()
         {
@@ -122,7 +122,7 @@ public class ChainedExecutionQueryRunner<T> implements QueryRunner<T>
                                   public Iterable<T> call() throws Exception
                                   {
                                     try {
-                                      Sequence<T> result = input.run(queryPlus, responseContext);
+                                      Sequence<T> result = input.run(threadSafeQueryPlus, responseContext);
                                       if (result == null) {
                                         throw new ISE("Got a null result! Segments are missing!");
                                       }

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

@@ -31,17 +31,42 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.TimeUnit;
 
+/**
+ * DefaultQueryMetrics is unsafe for use from multiple threads. It fails with RuntimeException on access not from the
+ * thread where it was constructed. To "transfer" DefaultQueryMetrics from one thread to another {@link #ownerThread}
+ * field should be updated.
+ */
 public class DefaultQueryMetrics<QueryType extends Query<?>> implements QueryMetrics<QueryType>
 {
   protected final ObjectMapper jsonMapper;
   protected final ServiceMetricEvent.Builder builder = new ServiceMetricEvent.Builder();
   protected final Map<String, Number> metrics = new HashMap<>();
 
+  /** Non final to give subclasses ability to reassign it. */
+  protected Thread ownerThread = Thread.currentThread();
+
   public DefaultQueryMetrics(ObjectMapper jsonMapper)
   {
     this.jsonMapper = jsonMapper;
   }
 
+  protected void checkModifiedFromOwnerThread()
+  {
+    if (Thread.currentThread() != ownerThread) {
+      throw new IllegalStateException(
+          "DefaultQueryMetrics must not be modified from multiple threads. If it is needed to gather dimension or "
+          + "metric information from multiple threads or from an async thread, this information should explicitly be "
+          + "passed between threads (e. g. using Futures), or this DefaultQueryMetrics's ownerThread should be "
+          + "reassigned explicitly");
+    }
+  }
+
+  protected void setDimension(String dimension, String value)
+  {
+    checkModifiedFromOwnerThread();
+    builder.setDimension(dimension, value);
+  }
+
   @Override
   public void query(QueryType query)
   {
@@ -56,18 +81,19 @@ public class DefaultQueryMetrics<QueryType extends Query<?>> implements QueryMet
   @Override
   public void dataSource(QueryType query)
   {
-    builder.setDimension(DruidMetrics.DATASOURCE, DataSourceUtil.getMetricName(query.getDataSource()));
+    setDimension(DruidMetrics.DATASOURCE, DataSourceUtil.getMetricName(query.getDataSource()));
   }
 
   @Override
   public void queryType(QueryType query)
   {
-    builder.setDimension(DruidMetrics.TYPE, query.getType());
+    setDimension(DruidMetrics.TYPE, query.getType());
   }
 
   @Override
   public void interval(QueryType query)
   {
+    checkModifiedFromOwnerThread();
     builder.setDimension(
         DruidMetrics.INTERVAL,
         query.getIntervals().stream().map(Interval::toString).toArray(String[]::new)
@@ -77,32 +103,28 @@ public class DefaultQueryMetrics<QueryType extends Query<?>> implements QueryMet
   @Override
   public void hasFilters(QueryType query)
   {
-    builder.setDimension("hasFilters", String.valueOf(query.hasFilters()));
+    setDimension("hasFilters", String.valueOf(query.hasFilters()));
   }
 
   @Override
   public void duration(QueryType query)
   {
-    builder.setDimension("duration", query.getDuration().toString());
+    setDimension("duration", query.getDuration().toString());
   }
 
   @Override
   public void queryId(QueryType query)
   {
-    builder.setDimension(DruidMetrics.ID, Strings.nullToEmpty(query.getId()));
+    setDimension(DruidMetrics.ID, Strings.nullToEmpty(query.getId()));
   }
 
   @Override
   public void context(QueryType query)
   {
     try {
-      builder.setDimension(
+      setDimension(
           "context",
-          jsonMapper.writeValueAsString(
-              query.getContext() == null
-              ? ImmutableMap.of()
-              : query.getContext()
-          )
+          jsonMapper.writeValueAsString(query.getContext() == null ? ImmutableMap.of() : query.getContext())
       );
     }
     catch (JsonProcessingException e) {
@@ -113,111 +135,115 @@ public class DefaultQueryMetrics<QueryType extends Query<?>> implements QueryMet
   @Override
   public void server(String host)
   {
-    builder.setDimension("server", host);
+    setDimension("server", host);
   }
 
   @Override
   public void remoteAddress(String remoteAddress)
   {
-    builder.setDimension("remoteAddress", remoteAddress);
+    setDimension("remoteAddress", remoteAddress);
   }
 
   @Override
   public void status(String status)
   {
-    builder.setDimension(DruidMetrics.STATUS, status);
+    setDimension(DruidMetrics.STATUS, status);
   }
 
   @Override
   public void success(boolean success)
   {
-    builder.setDimension("success", String.valueOf(success));
+    setDimension("success", String.valueOf(success));
   }
 
   @Override
   public void segment(String segmentIdentifier)
   {
-    builder.setDimension("segment", segmentIdentifier);
+    setDimension("segment", segmentIdentifier);
   }
 
   @Override
   public void chunkInterval(Interval interval)
   {
-    builder.setDimension("chunkInterval", interval.toString());
+    setDimension("chunkInterval", interval.toString());
   }
 
   @Override
   public QueryMetrics<QueryType> reportQueryTime(long timeNs)
   {
-    return defaultTimeMetric("query/time", timeNs);
+    return reportMillisTimeMetric("query/time", timeNs);
   }
 
   @Override
   public QueryMetrics<QueryType> reportQueryBytes(long byteCount)
   {
-    metrics.put("query/bytes", byteCount);
-    return this;
+    return reportMetric("query/bytes", byteCount);
   }
 
   @Override
   public QueryMetrics<QueryType> reportWaitTime(long timeNs)
   {
-    return defaultTimeMetric("query/wait/time", timeNs);
+    return reportMillisTimeMetric("query/wait/time", timeNs);
   }
 
   @Override
   public QueryMetrics<QueryType> reportSegmentTime(long timeNs)
   {
-    return defaultTimeMetric("query/segment/time", timeNs);
+    return reportMillisTimeMetric("query/segment/time", timeNs);
   }
 
   @Override
   public QueryMetrics<QueryType> reportSegmentAndCacheTime(long timeNs)
   {
-    return defaultTimeMetric("query/segmentAndCache/time", timeNs);
+    return reportMillisTimeMetric("query/segmentAndCache/time", timeNs);
   }
 
   @Override
   public QueryMetrics<QueryType> reportIntervalChunkTime(long timeNs)
   {
-    return defaultTimeMetric("query/intervalChunk/time", timeNs);
+    return reportMillisTimeMetric("query/intervalChunk/time", timeNs);
   }
 
   @Override
   public QueryMetrics<QueryType> reportCpuTime(long timeNs)
   {
-    metrics.put("query/cpu/time", TimeUnit.NANOSECONDS.toMicros(timeNs));
-    return this;
+    return reportMetric("query/cpu/time", TimeUnit.NANOSECONDS.toMicros(timeNs));
   }
 
   @Override
   public QueryMetrics<QueryType> reportNodeTimeToFirstByte(long timeNs)
   {
-    return defaultTimeMetric("query/node/ttfb", timeNs);
+    return reportMillisTimeMetric("query/node/ttfb", timeNs);
   }
 
   @Override
   public QueryMetrics<QueryType> reportNodeTime(long timeNs)
   {
-    return defaultTimeMetric("query/node/time", timeNs);
+    return reportMillisTimeMetric("query/node/time", timeNs);
   }
 
-  private QueryMetrics<QueryType> defaultTimeMetric(String metricName, long timeNs)
+  private QueryMetrics<QueryType> reportMillisTimeMetric(String metricName, long timeNs)
   {
-    metrics.put(metricName, TimeUnit.NANOSECONDS.toMillis(timeNs));
+    return reportMetric(metricName, TimeUnit.NANOSECONDS.toMillis(timeNs));
+  }
+
+  protected QueryMetrics<QueryType> reportMetric(String metricName, Number value)
+  {
+    checkModifiedFromOwnerThread();
+    metrics.put(metricName, value);
     return this;
   }
 
   @Override
   public QueryMetrics<QueryType> reportNodeBytes(long byteCount)
   {
-    metrics.put("query/node/bytes", byteCount);
-    return this;
+    return reportMetric("query/node/bytes", byteCount);
   }
 
   @Override
   public void emit(ServiceEmitter emitter)
   {
+    checkModifiedFromOwnerThread();
     for (Map.Entry<String, Number> metric : metrics.entrySet()) {
       emitter.emit(builder.build(metric.getKey(), metric.getValue()));
     }

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

@@ -92,8 +92,8 @@ public class GroupByMergedQueryRunner<T> implements QueryRunner<T>
     final Pair<Queue, Accumulator<Queue, T>> bySegmentAccumulatorPair = GroupByQueryHelper.createBySegmentAccumulatorPair();
     final boolean bySegment = QueryContexts.isBySegment(query);
     final int priority = QueryContexts.getPriority(query);
-
-    ListenableFuture<List<Void>> futures = Futures.allAsList(
+    final QueryPlus<T> threadSafeQueryPlus = queryPlus.withoutThreadUnsafeState();
+    final ListenableFuture<List<Void>> futures = Futures.allAsList(
         Lists.newArrayList(
             Iterables.transform(
                 queryables,
@@ -114,10 +114,10 @@ public class GroupByMergedQueryRunner<T> implements QueryRunner<T>
                           {
                             try {
                               if (bySegment) {
-                                input.run(queryPlus, responseContext)
+                                input.run(threadSafeQueryPlus, responseContext)
                                      .accumulate(bySegmentAccumulatorPair.lhs, bySegmentAccumulatorPair.rhs);
                               } else {
-                                input.run(queryPlus, responseContext)
+                                input.run(threadSafeQueryPlus, responseContext)
                                      .accumulate(indexAccumulatorPair.lhs, indexAccumulatorPair.rhs);
                               }
 

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

@@ -34,19 +34,19 @@ import java.util.function.ObjLongConsumer;
 public class MetricsEmittingQueryRunner<T> implements QueryRunner<T>
 {
   private final ServiceEmitter emitter;
-  private final QueryToolChest<?, ? super Query<T>> queryToolChest;
+  private final QueryToolChest<T, ? extends Query<T>> queryToolChest;
   private final QueryRunner<T> queryRunner;
   private final long creationTimeNs;
-  private final ObjLongConsumer<? super QueryMetrics<? super Query<T>>> reportMetric;
-  private final Consumer<QueryMetrics<? super Query<T>>> applyCustomDimensions;
+  private final ObjLongConsumer<? super QueryMetrics<?>> reportMetric;
+  private final Consumer<QueryMetrics<?>> applyCustomDimensions;
 
   private MetricsEmittingQueryRunner(
       ServiceEmitter emitter,
-      QueryToolChest<?, ? super Query<T>> queryToolChest,
+      QueryToolChest<T, ? extends Query<T>> queryToolChest,
       QueryRunner<T> queryRunner,
       long creationTimeNs,
-      ObjLongConsumer<? super QueryMetrics<? super Query<T>>> reportMetric,
-      Consumer<QueryMetrics<? super Query<T>>> applyCustomDimensions
+      ObjLongConsumer<? super QueryMetrics<?>> reportMetric,
+      Consumer<QueryMetrics<?>> applyCustomDimensions
   )
   {
     this.emitter = emitter;
@@ -59,10 +59,10 @@ public class MetricsEmittingQueryRunner<T> implements QueryRunner<T>
 
   public MetricsEmittingQueryRunner(
       ServiceEmitter emitter,
-      QueryToolChest<?, ? super Query<T>> queryToolChest,
+      QueryToolChest<T, ? extends Query<T>> queryToolChest,
       QueryRunner<T> queryRunner,
-      ObjLongConsumer<? super QueryMetrics<? super Query<T>>> reportMetric,
-      Consumer<QueryMetrics<? super Query<T>>> applyCustomDimensions
+      ObjLongConsumer<? super QueryMetrics<?>> reportMetric,
+      Consumer<QueryMetrics<?>> applyCustomDimensions
   )
   {
     this(emitter, queryToolChest, queryRunner, -1, reportMetric, applyCustomDimensions);
@@ -83,8 +83,8 @@ public class MetricsEmittingQueryRunner<T> implements QueryRunner<T>
   @Override
   public Sequence<T> run(final QueryPlus<T> queryPlus, final Map<String, Object> responseContext)
   {
-    QueryPlus<T> queryWithMetrics = queryPlus.withQueryMetrics((QueryToolChest<T, ? extends Query<T>>) queryToolChest);
-    final QueryMetrics<? super Query<T>> queryMetrics = (QueryMetrics<? super Query<T>>) queryWithMetrics.getQueryMetrics();
+    QueryPlus<T> queryWithMetrics = queryPlus.withQueryMetrics(queryToolChest);
+    final QueryMetrics<?> queryMetrics = queryWithMetrics.getQueryMetrics();
 
     applyCustomDimensions.accept(queryMetrics);
 

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

@@ -66,6 +66,11 @@ public final class QueryPlus<T>
    * Returns the same QueryPlus object, if it already has {@link QueryMetrics} ({@link #getQueryMetrics()} returns not
    * null), or returns a new QueryPlus object with {@link Query} from this QueryPlus and QueryMetrics created using the
    * given {@link QueryToolChest}, via {@link QueryToolChest#makeMetrics(Query)} method.
+   *
+   * By convention, callers of {@code withQueryMetrics()} must also call .getQueryMetrics().emit() on the returned
+   * QueryMetrics object, regardless if this object is the same as the object on which .withQueryMetrics() was initially
+   * called (i. e. it already had non-null QueryMetrics), or if it is a new QueryPlus object. See {@link
+   * MetricsEmittingQueryRunner} for example.
    */
   public QueryPlus<T> withQueryMetrics(QueryToolChest<T, ? extends Query<T>> queryToolChest)
   {
@@ -76,6 +81,31 @@ public final class QueryPlus<T>
     }
   }
 
+  /**
+   * Returns a QueryPlus object without the components which are unsafe for concurrent use from multiple threads,
+   * therefore couldn't be passed down in concurrent or async {@link QueryRunner}s.
+   *
+   * Currently the only unsafe component is {@link QueryMetrics}, i. e. {@code withoutThreadUnsafeState()} call is
+   * equivalent to {@link #withoutQueryMetrics()}.
+   */
+  public QueryPlus<T> withoutThreadUnsafeState()
+  {
+    return withoutQueryMetrics();
+  }
+
+  /**
+   * Returns the same QueryPlus object, if it doesn't have {@link QueryMetrics} ({@link #getQueryMetrics()} returns
+   * null), or returns a new QueryPlus object with {@link Query} from this QueryPlus and null as QueryMetrics.
+   */
+  private QueryPlus<T> withoutQueryMetrics()
+  {
+    if (queryMetrics == null) {
+      return this;
+    } else {
+      return new QueryPlus<>(query, null);
+    }
+  }
+
   /**
    * Equivalent of withQuery(getQuery().withQuerySegmentSpec(spec)).
    */

processing/src/main/java/io/druid/query/groupby/DefaultGroupByQueryMetrics.java

@@ -43,19 +43,19 @@ public class DefaultGroupByQueryMetrics extends DefaultQueryMetrics<GroupByQuery
   @Override
   public void numDimensions(GroupByQuery query)
   {
-    builder.setDimension("numDimensions", String.valueOf(query.getDimensions().size()));
+    setDimension("numDimensions", String.valueOf(query.getDimensions().size()));
   }
 
   @Override
   public void numMetrics(GroupByQuery query)
   {
-    builder.setDimension("numMetrics", String.valueOf(query.getAggregatorSpecs().size()));
+    setDimension("numMetrics", String.valueOf(query.getAggregatorSpecs().size()));
   }
 
   @Override
   public void numComplexMetrics(GroupByQuery query)
   {
     int numComplexAggs = DruidMetrics.findNumComplexAggs(query.getAggregatorSpecs());
-    builder.setDimension("numComplexMetrics", String.valueOf(numComplexAggs));
+    setDimension("numComplexMetrics", String.valueOf(numComplexAggs));
   }
 }

processing/src/main/java/io/druid/query/groupby/epinephelinae/GroupByMergingQueryRunnerV2.java

@@ -119,9 +119,11 @@ public class GroupByMergingQueryRunnerV2 implements QueryRunner<Row>
         CTX_KEY_MERGE_RUNNERS_USING_CHAINED_EXECUTION,
         false
     );
-    final QueryPlus<Row> queryPlusForRunners = queryPlus.withQuery(
-        query.withOverriddenContext(ImmutableMap.<String, Object>of(CTX_KEY_MERGE_RUNNERS_USING_CHAINED_EXECUTION, true))
-    );
+    final QueryPlus<Row> queryPlusForRunners = queryPlus
+        .withQuery(
+            query.withOverriddenContext(ImmutableMap.<String, Object>of(CTX_KEY_MERGE_RUNNERS_USING_CHAINED_EXECUTION, true))
+        )
+        .withoutThreadUnsafeState();
 
     if (QueryContexts.isBySegment(query) || forceChainedExecution) {
       ChainedExecutionQueryRunner<Row> runner = new ChainedExecutionQueryRunner<>(exec, queryWatcher, queryables);

processing/src/main/java/io/druid/query/metadata/SegmentMetadataQueryRunnerFactory.java

@@ -205,14 +205,18 @@ public class SegmentMetadataQueryRunnerFactory implements QueryRunnerFactory<Seg
                   {
                     final Query<SegmentAnalysis> query = queryPlus.getQuery();
                     final int priority = QueryContexts.getPriority(query);
-                    ListenableFuture<Sequence<SegmentAnalysis>> future = queryExecutor.submit(
+                    final QueryPlus<SegmentAnalysis> threadSafeQueryPlus = queryPlus.withoutThreadUnsafeState();
+                    final ListenableFuture<Sequence<SegmentAnalysis>> future = queryExecutor.submit(
                         new AbstractPrioritizedCallable<Sequence<SegmentAnalysis>>(priority)
                         {
                           @Override
                           public Sequence<SegmentAnalysis> call() throws Exception
                           {
                             return Sequences.simple(
-                                Sequences.toList(input.run(queryPlus, responseContext), new ArrayList<>())
+                                Sequences.toList(
+                                    input.run(threadSafeQueryPlus, responseContext),
+                                    new ArrayList<>()
+                                )
                             );
                           }
                         }

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

@@ -42,13 +42,13 @@ public class DefaultTimeseriesQueryMetrics extends DefaultQueryMetrics<Timeserie
   @Override
   public void numMetrics(TimeseriesQuery query)
   {
-    builder.setDimension("numMetrics", String.valueOf(query.getAggregatorSpecs().size()));
+    setDimension("numMetrics", String.valueOf(query.getAggregatorSpecs().size()));
   }
 
   @Override
   public void numComplexMetrics(TimeseriesQuery query)
   {
     int numComplexAggs = DruidMetrics.findNumComplexAggs(query.getAggregatorSpecs());
-    builder.setDimension("numComplexMetrics", String.valueOf(numComplexAggs));
+    setDimension("numComplexMetrics", String.valueOf(numComplexAggs));
   }
 }

processing/src/main/java/io/druid/query/topn/DefaultTopNQueryMetrics.java

@@ -44,25 +44,25 @@ public class DefaultTopNQueryMetrics extends DefaultQueryMetrics<TopNQuery> impl
   @Override
   public void threshold(TopNQuery query)
   {
-    builder.setDimension("threshold", String.valueOf(query.getThreshold()));
+    setDimension("threshold", String.valueOf(query.getThreshold()));
   }
 
   @Override
   public void dimension(TopNQuery query)
   {
-    builder.setDimension("dimension", query.getDimensionSpec().getDimension());
+    setDimension("dimension", query.getDimensionSpec().getDimension());
   }
 
   @Override
   public void numMetrics(TopNQuery query)
   {
-    builder.setDimension("numMetrics", String.valueOf(query.getAggregatorSpecs().size()));
+    setDimension("numMetrics", String.valueOf(query.getAggregatorSpecs().size()));
   }
 
   @Override
   public void numComplexMetrics(TopNQuery query)
   {
     int numComplexAggs = DruidMetrics.findNumComplexAggs(query.getAggregatorSpecs());
-    builder.setDimension("numComplexMetrics", String.valueOf(numComplexAggs));
+    setDimension("numComplexMetrics", String.valueOf(numComplexAggs));
   }
 }

server/src/main/java/io/druid/segment/realtime/appenderator/SinkQuerySegmentWalker.java

@@ -275,7 +275,7 @@ public class SinkQuerySegmentWalker implements QuerySegmentWalker
    */
   private <T> QueryRunner<T> withPerSinkMetrics(
       final QueryRunner<T> sinkRunner,
-      final QueryToolChest<?, ? super Query<T>> queryToolChest,
+      final QueryToolChest<T, ? extends Query<T>> queryToolChest,
       final String sinkSegmentIdentifier,
       final AtomicLong cpuTimeAccumulator
   )