Hi Kristian, Monty asked me to connect with you regarding global transaction IDs in MariaDB. I reviewed some time ago the MySQL 5.6 global transaction ID design and implementation. Unfortunately I really did not like what I found, to the point that I decided this was not something we would want to have or support in MariaDB (see https://lists.launchpad.net/maria-developers/msg04837.html for an ealier mail on this). Both you and Giuseppe also had critisisms about it. Instead I came up with a (in my opinion) better design. I have now written this up in (great) detail here: https://mariadb.atlassian.net/browse/MDEV-26 It would be great if you (/your team) could comment on this and how it relates to what you need or any comments/suggestions etc. I know it is a long text, and a complex problem, so also feel free to just ask me for any clarifications or explanations you would like, even without digging through the whole text. The basic idea is to keep the existing concept of a stream of replication events and a slave's current position within this stream, but in a way that is uniform across the whole multi-level replication topology (global transaction ID), and that facilitates simple scripting of automated promotion of a new master. I have thought for a long time over this problem and how to best approach it and make it work well both with existing replication usage and with new features like multi-source and parallel replication. It is hard to get right, but I am fairly pleased with what I have ended up with so far. I am hopeful that this will be a good way forward, but I very much welcome any comments or alternate suggestions. Regards, - (the other) Kristian.