rht_del deletes a key from the specified replica. If an equivalent key exists in the replica, then the corresponding key-value pair will be removed.

Success (the return code) does not depend on whether or not an equivalent key already exists in the rht. The function generates an update to delete the specified key and it is unknown if the key match was found until the update comes back from the network and is applied. If is required to know if the delete was successful, us the on_update callback.

Remember that for RHT_UNION semantics no entry is left behind marking the key as deleted, whereas for RHT_INTERSECT semantics one is.

Also, the same note for rht_put applies to rht_del. If the delete of an entry is initiated around the same time as other updates to that entry, which update will eventually "win" and whether all those updates will be applied or not is determined by the LTSs (Lamport Time Stamp) of the updates.