Sachin Setiya <[email protected]> writes: > I have some question related to rpl_slave_state. Suppose A circular > async replication between A < -- > B (gtid_ignore_duplicates on)
Why do you set gtid_ignore_duplicates? This option is for multi-source replication: https://mariadb.com/kb/en/library/gtid/#gtid_ignore_duplicates "When set, different master connections in multi-source replication are allowed to receive and process event groups with the same GTID" But you are not using multi-source connection here, there is only one master connection (eg. connection to B on slave A). Thus, the option will do nothing in this case. > Now, we set some temp server_id on server A , lets say `X`. Now the > problem is each event group which > originates from A is executed 2 times. For example we insert into > table t1 and gtid is 0-X-2. The event goes to slave B > B applies it, And send it back to A, Since its server_is different I think here you mean that A has server_id=1 (eg), B has server_id=2, but on A you do SET server_id=3; INSERT INTO t1 VALUES (1); But there is no server with server_id=3 anywhere. In this case, you need to break the circle yourself somewhere. For example by CHANGE MASTER ... IGNORE_SERVER_IDS=3 on A. To my knowledge, this has always been so for ring replication. > Andrei suggested a solution of checking rpl_binlog_state in > check_duplicate_gtid, This solution solves some problem but creates It seems you think that --gtid-ignore-duplicates should magically ignore any apply of duplicate GTID. But that is not the case, as the documentation states (though admittedly rather briefly). --gtid-ignore-duplicates is _only_ for multi-source replication (so perhaps unfortunately named). In this case, the conflict is not between GTIDs replicated from different master connections. It is a conflict between a transaction originated on a master with a transaction replicated from another master. > write gtid_event in log. But this does not make sense. rpl_slave_state > should be used for slave replication usage. Agree. rpl_binlog_state should not be involved in slave GTID processing. There should be a clear separation: rpl_slave_state is what a slave has applied from another master. rpl_binlog state is what a master has originated. The gtid_ignore_duplicates option is already very difficult for users to understand and use correctly. It would be a mistake to make it even more complicated. Also, this seems to originate from some Galera issue. It is well known that Galera was merged prematurely into MariaDB with a broken design, and this was never fixed. Galera issues must never influence how non-galera replication (which at least attempts to have a proper design) works. Hope this helps, - Kristian. _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp
