Before druid-0.15 (if you are lucky and using an older version) you can give a try to insert-segment-to-db tool
This tool has been discontinued due to the reasons mentioned in the above doc since druid-0.15.
I don’t think we can read the segments consistently without corresponding metadatabase entries and I am not even sure if we can rebuild the metadata entries manually (it should be a lot of manual effort and tricky even if it’s doable ). Maybe someone, who has done this in the past can provide better details on “how to rebuild the metastore in this scenario”.
To Avoid this in future :
- Take regular snapshots of the metadata storage (very important).
- Back up new segments in deep storage when they appear. It isn’t important to take consistent snapshots, just to get every file eventually.
For , You can trust your deep storage (like S3/Azure/ etc ) but  is still very important .
Thanks and Regards,