[druid-user] Data segments still remaining in the deep storage after being merged

Druid uses versioning for segments and for any interval segments with latest version gets loaded on the historical nodes.
When merge task completes, older segments get dropped from historical nodes and new merged one gets loaded.

However, by default druid is designed not to delete the segments from deep storage.

The default behavior can be changed by setting druid.coordinator.kill.on to true.

Other related configs can be found here http://druid.io/docs/latest/configuration/index.html