This is a good primer for tombstones: How to recover tombstones faster
It isn’t a fixed amount of time, it depends on many factors which include how many copies of the deleted record are still on the disk in live blocks or free blocks that haven’t been overwritten.
The “Tomb Raider” is a periodic device scan that does a mark and sweep style GC of tombstones. Only when the disk scan finds that a digest no longer exists on any device does Aerospike know that the record is truly removed from the local machine. At which time the tombstone may be removed if eligible based on
If a node was taken offline prior to a record being deleted and that node returns to the cluster after
tomb-raider-eligible-age seconds then that returning node could resurrect the record. To prevent this, you should zeroize a node when it has been down for more then