Druid merge segments

1、Kafka Indexing Service produces a large number of segments,Try to merge segments with bulk tasks (

Hadoop-based Batch Ingestion

),but it very slowly ,

Merge a few days of segements, takes about one day, sometimes not successful。

2、druid.coordinator.merge.on=true ,Use automatic merge task, the task is not executed?

2、

The automatic merge tasks controlled by “druid.coordinator.merge.on=true” don’t work on the segments generated by the Kafka indexing service, the docs mention the reason for that in the last section: “Note that the Merge Task and Append Task described here will not work as they require unsharded segments while Kafka indexing tasks always generated sharded segments.” (http://druid.io/docs/latest/development/extensions-core/kafka-ingestion.html)