Greetings, I've had this issue before and never quite got to the bottom of it. It keeps biting me and I'm hoping I can figure out how to definitively solve it. In brief, my replica server has this for gtid_slave_pos: 0-303-67739600,1-303-7360639083,100-303-4337869 And my primary server has: gtid_binlog_pos 0-303-67739600,1-303-7363061243,100-303-4338582 gtid_binlog_state 0-302-67690294,0-301-67719794,0-303-67739600,1-301-7350472534,1-302-7350381758,1-303-7363061243,100-302-4242958,100-301-4332195,100-303-4338582 That's all well and good and I can connect that way. But if I do this on the replica server: stop slave; select @@global.gtid_slave_pos; 0-303-67739600,1-303-7360639083,100-303-4337869 set global gtid_slave_pos = '1-303-7360639083,100-303-4337869'; start slave; I get: Got fatal error 1236 from master when reading data from binary log: 'Could not find GTID state requested by slave in any binlog files. Probably the slave state is too old and required binlog files have been purged. Even though I'm positive there are no domain 0 transactions (again, hasn't been in service for years). If I add the `0-303-67739600` back in to gtid_slave_pos I can reconnect. At this point, I have only one server of a four server chain that I can actually connect to with gtid (as above). So I'm a little reluctant to do too much experimenting. But just to ask the question, if I: FLUSH BINARY LOGS DELETE_DOMAIN_ID=(0) on the master, would I then be able to connect to it via set global gtid_slave_pos = '1-303-7360639083,100-303-4337869'; from the replica? At this point, I cannot connect any of my other servers (which currently are all replicating from the same master) to each other, even the ones that don't show the 0- domain in the gtid-binlog vars. I'm hoping if I can figure out the above scenario it might help me deal with the rest, but I just keep feeling like I'm missing something. TIA, Dan