The 7-day default splits the retention policy into 7-day windows. The expiry time is the time when the data is actually deleted.
The database will only drop whole shards at a time. If you use the influx cli to run SHOW SHARDS you should see a listing of your database with their respective shards. Each of those shards has an expiry_time . Each check-interval the database will drop any of the shards who’s expiry times are older than time.Now() .
