I'm running a MySQL server 5.5.44, and I'd need to sync its data to a new server running MySQL 5.7.13 using master-slave. The idea is to bring both DBs synced until we migrate to the second, newer server, achieving a close to zero downtime.
The issue is not about how to prepare the master-slave. The issue comes when I want to sync the data, but change the engine of many tables in our slave server. Specifically, moving them from MyISAM to InnoDB.
These tables are larger than 1Gb, one being 14Gb, which would lead in a lock for more than 8 hours. My idea was to do any structural optimisation in the slave server, but I'm afraid this might compromise the whole master-slave thing.
Do you know if this is possible?