A global transaction identifier (GTID) is a unique identifier created and associated with each transaction committed on the server of origin (master). This identifier is unique, not only to the server on which it originated, but also across all servers in a given replication setup. There is a one-to-one mapping between all transactions and all GTIDs.
A GTID is represented as a pair of coordinates, separated by a colon character (:):
GTID = source_id:transaction_id
The source_id option identifies the originating server. Normally, the server's server_uuid option is used for this purpose. The transaction_id option is a sequence number determined by the order in which the transaction was committed on this server. For ...
