Apache Druid

Do you have <https://druid.apache.org/docs/latest/operations/clean-metadata-store.html#segment-records-and-segments-in-deep-storage-kill-task|automated cleanup> enabled?  (I think it might be on by default lately, but don't remember for sure.)

You can shut down, clear the cache, restart.  But also make sure you're not just growing and need more historicals or disk space, so it doesn't just repeat.

`druid.coordinator.kill.on` needs to be true.
To clean the directory after that setting is turned on, you can actually just delete the unwanted folders under segment-cache folder and then roll restart historical one by one.

if druid is not clearing the old files from historicals, then it seems like a bug. Historicals also shouldn't be loading more than the size of configured segment cache. So if you see a historical not honoring that setting, it could be some bug.

you should file a GH issue if you suspect the same