How to swap a replication and a master database with each other efficiently

On the master database

1. set the master database on read only

SET GLOBAL super_read_only = ON;
SET GLOBAL read_only = ON;

2. find the last bin log position and file to later make this the replica

SHOW MASTER STATUS;

mysql> SHOW MASTER STATUS;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.011112 |  5895164 | emplemdb     |                  |                   |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

Save this output to a text file

On slave database

stop the slave status and check the read only status. It should stop being read only

STOP SLAVE;

RESET SLAVE ALL;

Now this is your new master database

Change the app credentials to look at the slave database

On the old server setup the slave status and start slave