A method is provided for asynchronously tracking the replication of data
writes from an application that is subject to system and network failure,
to a standby data processing unit located at a standby site. The method
includes the step of enabling access to sequence numbers created for use
in replication of the data writes. Another step is sending the data writes
to a remote mirroring module. Next is assigning sequence numbers to each
data write accepted. It can then be determined when data writes at a local
site have been successfully replicated at the standby site by correlating
the most recent local write sequence number and most recent replication
sequence number. An additional step is initiating replication of the data
writes for which replication has not taken place.
