Described are data replication techniques. Y cycles of writes directed to a first storage device of a first data storage system are collected, Y>2. Each of the Y cycles denotes writes directed to the first storage device at an occurrence of a fixed time interval. Writes of cycle N−1 directed to the first storage device are transmitted from the first data storage system to a second data storage system. Writes of cycle N−2 are applied to a second storage device. An acknowledgement regarding cycle N−1 is sent from the second data storage system to the first data storage system responsive to determining that the writes of cycle N−1 directed to the first storage device have been received by the second data storage system and that the writes of cycle N−2 directed to the first storage device have been applied to the second storage device.