ROBUST COMMUNICATION SYSTEM FOR GUARANTEED MESSAGE SEQUENCING WITH THE DETECTION OF DUPLICATE SENDERS

Guaranteed message sequencing between a first and second database is described. An example method includes maintaining first state information associated with the first database at the first database, where second state information associated with the first database is maintained at the second database. The client sends, to the second database, a message describing changed rows between the first database and the second database since a last synchronization and the first state information. The client subsequently receives, from the second database, status of the last synchronization, where the status is determined by the second database based on the first state information and the second state information.