DoublesSketchAggregatorFactory doesn't implement makeAggregateCombiner

[jon-wei]

In 0.13.0-incubating, using a quantilesDoubleSketch aggregator at ingestion will result in the following exception during index merging:

2019-01-16T02:51:54,693 ERROR [publish-0] org.apache.druid.indexing.kafka.IncrementalPublishingKafkaIndexTaskRunner - Error while publishing segments for sequence[SequenceMetadata{sequenceName='index_kafka_BRS_PAGE_MIN_0361b88dfbdfe35_0', sequenceId=0, startOffsets={0=10213925, 1=10824117}, endOffsets={0=10480548, 1=11090740}, assignments=[], sentinel=false, checkpointed=true}]
org.apache.druid.java.util.common.UOE: [org.apache.druid.query.aggregation.datasketches.quantiles.DoublesSketchAggregatorFactory] does not implement makeAggregateCombiner()
	at org.apache.druid.query.aggregation.AggregatorFactory.makeAggregateCombiner(AggregatorFactory.java:79) ~[druid-processing-0.13.0-incubating.jar:0.13.0-incubating]
	at org.apache.druid.query.aggregation.AggregatorFactory.makeNullableAggregateCombiner(AggregatorFactory.java:93) ~[druid-processing-0.13.0-incubating.jar:0.13.0-incubating]
	at org.apache.druid.segment.RowCombiningTimeAndDimsIterator.lambda$new$1(RowCombiningTimeAndDimsIterator.java:120) ~[druid-processing-0.13.0-incubating.jar:0.13.0-incubating]
	at java.util.Arrays.setAll(Arrays.java:4698) ~[?:1.8.0_60]
	at org.apache.druid.segment.RowCombiningTimeAndDimsIterator.<init>(RowCombiningTimeAndDimsIterator.java:120) ~[druid-processing-0.13.0-incubating.jar:0.13.0-incubating]
	at org.apache.druid.segment.IndexMergerV9.lambda$merge$2(IndexMergerV9.java:909) ~[druid-processing-0.13.0-incubating.jar:0.13.0-incubating]
	at org.apache.druid.segment.IndexMergerV9.makeMergedTimeAndDimsIterator(IndexMergerV9.java:1031) ~[druid-processing-0.13.0-incubating.jar:0.13.0-incubating]
	at org.apache.druid.segment.IndexMergerV9.makeIndexFiles(IndexMergerV9.java:179) ~[druid-processing-0.13.0-incubating.jar:0.13.0-incubating]
	at org.apache.druid.segment.IndexMergerV9.merge(IndexMergerV9.java:914) ~[druid-processing-0.13.0-incubating.jar:0.13.0-incubating]
	at org.apache.druid.segment.IndexMergerV9.mergeQueryableIndex(IndexMergerV9.java:832) ~[druid-processing-0.13.0-incubating.jar:0.13.0-incubating]
	at org.apache.druid.segment.IndexMergerV9.mergeQueryableIndex(IndexMergerV9.java:810) ~[druid-processing-0.13.0-incubating.jar:0.13.0-incubating]
	at org.apache.druid.segment.realtime.appenderator.AppenderatorImpl.mergeAndPush(AppenderatorImpl.java:719) ~[druid-server-0.13.0-incubating.jar:0.13.0-incubating]
	at org.apache.druid.segment.realtime.appenderator.AppenderatorImpl.lambda$push$1(AppenderatorImpl.java:623) ~[druid-server-0.13.0-incubating.jar:0.13.0-incubating]
	at com.google.common.util.concurrent.Futures$1.apply(Futures.java:713) ~[guava-16.0.1.jar:?]
	at com.google.common.util.concurrent.Futures$ChainingListenableFuture.run(Futures.java:861) [guava-16.0.1.jar:?]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_60]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_60]
	at java.lang.Thread.run(Thread.java:745) [?:1.8.0_60]

As reported here: #6853 (comment)

It looks like the sketch agg was added before #5335 was merged and doesn't have makeAggregateCombiner().