MySQL 5.7 Reference Manual
MySQL 5.7 Release Notes
The following sections provide information about upgrading and downgrading NDB Cluster 7.5 and 7.6.
Schema operations, including SQL DDL statements, cannot be performed while any data nodes are restarting, and thus during an online upgrade or downgrade of the cluster. For other information regarding the rolling restart procedure used to perform an online upgrade, see Section 6.5, “Performing a Rolling Restart of an NDB Cluster”.
Important
Only compatibility between MySQL versions with regard to
NDBCLUSTER is taken into account in
this section, and there are likely other issues to be
considered. As with any other MySQL software upgrade
or downgrade, you are strongly encouraged to review the relevant
portions of the MySQL Manual for the MySQL versions from which
and to which you intend to migrate, before attempting an upgrade
or downgrade of the NDB Cluster software. See
Upgrading MySQL. For information about upgrades to
NDB 7.6, see
Section 3.7.2, “Upgrading and Downgrading NDB 7.6”.