MySQL 5.6 Release Notes
Each replica connects to the source using a MySQL user name and
password, so there must be a user account on the source server
that the replica can use to connect. Any account can be used for
this operation, providing it has been granted the
REPLICATION SLAVE privilege. You
can choose to create a different account for each replica, or
connect to the source using the same account for each replica.
Although you do not have to create an account specifically for replication, you should be aware that the replication user name and password are stored in plain text in the replica's connection metadata repository file or table (see Section 17.2.2.2, “Replication Metadata Repositories”). Therefore, you may want to create a separate account that has privileges only for the replication process, to minimize the possibility of compromise to other accounts.
To create a new account, use CREATE
USER. To grant this account the privileges required
for replication, use the GRANT
statement. If you create an account solely for the purposes of
replication, that account needs only the
REPLICATION SLAVE privilege. For
example, to set up a new user, repl, that can
connect for replication from any host within the
example.com domain, issue these statements on
the source:
mysql> CREATE USER 'repl'@'%.example.com' IDENTIFIED BY 'password';
mysql> GRANT REPLICATION SLAVE ON *.* TO 'repl'@'%.example.com';See Section 13.7.1, “Account Management Statements”, for more information on statements for manipulation of user accounts.