Re: moving binlog_format in M-M while running

[Rick James]

Perhaps this will make it safe for live change:
Both machines: Stop all writes
Both machines: STOP SLAVE;
Both machines: SET @@global.binlog_format = ...;
Both machines: START SLAVE;

Alternatively:
Direct all writes to machine A.
Wait for B to be quite.
B: STOP SLAVE;
B: SET @@global.binlog_format = ...;
B: START SLAVE;
Failover so that all writes are going to B.
Repeat on A.