stop group_replication;
show global variables like 'gtid_purged';
set global gtid_purged='37e853da-8247-11e8-bce2-0242ac110001:1-138816383';
stop group_replication;
reset master;
flush logs;
start group_replication;
stop group_replication;
show global variables like 'gtid_purged';
set global gtid_purged='37e853da-8247-11e8-bce2-0242ac110001:1-138816383';
stop group_replication;
reset master;
flush logs;
start group_replication;