A much requested feature has made it to MySQL 5.7.6: Global Transaction Identifiers (GTIDs) can now be enabled online, without stopping writes, synchronizing servers, or restarting servers.
We introduced GTIDs in MySQL 5.6.6. GTIDs allow, among other things, seamless fail-over after a master has crashed. This enables highly available applications, since service can continue without interruption even if the master crashes. For new deployments, you could easily enable GTIDs right away – just set gtid-mode=ON in the configuration files. For deployments that accept a certain amount of downtime, you could switch from off to on too. However, for big deployments with strict limitations on downtime, this was more problematic, since you had to stop updates, sync all servers, and restart all servers simultaneously with GTIDs enabled, and this would lead to several minutes of downtime.
In MySQL 5.7.6, we have now made it possible to enable …
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