How to atomic execute getData and delete in distributed system

[fengguang gong]

Hi all：
when a znode is updated, there are four processes(1.2.3.4)can access the znode. 
Two cases:
(1)what i need is that there is only one process execute getData and delete 
atomically.
(2)what i need is that process4 execute getData and delete atomically.
In case (1), EPHEMERAL_SEQUENTIAL will be used.
In case (2), what should i do?