Currently, WATCH in a multi-exec transaction will ignore expired keys. So if a key that was previously being watched is expired and deleted from Redis, WATCH will not consider it at all... There is a TCL test for this behavior

https://github.com/redis/redis/blob/unstable/tests/unit/multi.tcl#L224

However, this behavior doesn't seem to make a lot of sense to me. If I am watching an item and the item gets deleted from Redis, I would want to be notified... Anyone know the reason behind this behavior in Redis?