If possible, the local version is a fragment of the master, containing only the subset needed for typical local operations. Copies of the local updates are forwarded asynchronously to a master copy of the data at a central location. Updates are posted to the master version of the data, possibly in batches, depending upon the appropriate balance of data currency and update efficiency. Updates destined for the dependent copies at the local nodes are later redistributed asynchronously. Updates are applied to the data fragment at the local node.
Users see the updated data.
Today's middleware products will eventually evolve into message brokers designed to support this processing style. Off-line transaction processing software is also appearing, to support mobile clients that demand a similar processing style.