Positional is the old style of tracking replication positions. It is deprecated in all our supported databases major releases.
replication-manager <=1.1 does not support MariaDB versions lower than 10.0, or MySQL versions lower than 5.6 and need MySQL GTID.
replication-manager 2.0 support positional replication
For MariaDB Server 10.0 and upper replication-manager always uses GTID positions for failover or switchover regardless of using GTID in the replication stream definition. In MariaDB, GTID are always present in the binary logs of MariaDB and can be used to point a slave to his master.
For MariaDB Server 10.0 and upper replication-manager can force positional replication back after a failover or a switchover but this will disable crash safe slave and usage of concurrency in replication streams.
|Automatically disable gtid mode on slave.
Positional replication will be used for pointing replication on MySQL or Percona Servers when no GTID replication is set.
In this scenario replication-manager is working in best effort mode as it was designed to work agent less. replication-manager does not parse binary logs to try to match correct position based on the content of replication EVENTS. GTID are here for fixing this requirement and we state that using them is the correct way to go.
replication-manager 2.0 can correct the database lack of unique EVENT identifier via PSEUDO GTID it find positions by reversing binary log via SQL command.
|Inject PseudoGTID and use them to rejoin extra slaves.
replication-manager design choices have implications:
On MariaDB 10.0 and later, positional replication will be lost after first switchover in favor of using GTID POS.
For other non-GTID databases extra slaves are staying under the old master. They are later moved on elected master by fixing invalid relay architectures. That means that the old master needs to rejoin the cluster first and we can't give insurance that this will succeed, if does not, you may have to reseed all slaves.
One can be inventive like having tree topology with slaves not monitored by the same replication-manager cluster so that the new elected master already gets available extra slaves.