Peter Laursen
I wonder if it will be possible to use replication with GTID's on a 'mixed pool' or MariaDB and MySQL5.6 machines? Is this a concern or not? I see a problem with the CLOUD where users may not be able to choose the server as they want. But if it is *plain impossible* to have both server versions in a setup, that's it of course. However if so this would then be MariaDB's first 'major break-off' from Oracle/MySQL.
There will be no problem replicating from MySQL -> MariaDB, or from MariaDB -> MySQL. Just as it will be possible to replicate between eg. MySQL 5.6 and MySQL 5.5. But such replication will use the old-style file-name-and-position mechanism, not global transaction IDs. Rest asured that maintaining replication compatibility between different versions remain a top priority! About using MySQL-style global transaction IDs on a MariaDB slave, or supplying a MySQL slave with MySQL-style global transaction IDs from a MariaDB master, this is not something I plan on doing. Their design is just too awkward and the implementation too lousy for me to want to support it. But think about it: Global transaction ID is really about being able to do automated scripting of failover to a new master, on production-critical systems. Do we really want to have a mixed setup of MariaDB and MySQL slaves, and automatically fail-over between them at random? I think this is an unlikely scenario, and not worth the effort to try to make work (if even possible). It might be more useful to have eg. a MariaDB slave, and be able to use MySQL-style global transaction IDs to automatically switch the MariaDB slave among a pool of MySQL masters. This may be possible, but I have not thought much about it yet. - Kristian.