Replication in Synchronous Mode This mode guarantees that all writing operations performed on the site where they were generated are recorded on the backup sites. As long as the writing has not been acknowledged by the replication service, the application can send no other record. Performances are based on the slowest writing speed of each site. The delays of data propagation including on long distances should be properly evaluated.
Replication in Asynchronous Mode Local and remote writing operations are separate in this mode. The replication service does not wait for the acknowledge of the remote writing to validate it in the application and accept the writing operations which follow. This mode more or less penalizes the application for writing, but is inconvenient as it has different datasets at a given time and does not guarantee data consistency.

Read More... Replication mode

Related articles