The Global Mailbox system uses a replication server for payload replication. The replication server transfers files at high speeds.
There is at least one replicator process in each data center that is responsible for replicating payloads. A table in Cassandra tracks the replication status of each payload file in each data center. The replicator processes use this table to find new payloads that exist in other data centers. The table provides a consolidated view of the state of all payloads in the system. This database table is also used when raising events. For example, the Message Add event is recorded when the payload exists in all data centers.