MySQL 5.7 Reference Manual
MySQL 5.7 Release Notes
The following sections describe how to set up replicas. Before you proceed, ensure that you have:
Configured the source with the necessary configuration properties. See Section 2.2.1, “Setting the Replication Source Configuration”.
Obtained the source's status information, or a copy of the source's binary log index file made during a shutdown for the data snapshot. See Section 2.2.3, “Obtaining the Replication Source's Binary Log Coordinates”.
On the source, released the read lock:
mysql> UNLOCK TABLES;