Tài liệu High Availability MySQL Cookbook phần 3

Congratulations! The cluster works, and you have created a table in it. You can repeat these
tests while powering off the storage nodes and watch the cluster continue to work. With a
single-cluster storage node powered off, everything will continue to work (except for the SQL
node that was previously running on the powered-off mode, of course!).
One of the key aspects of a highly-available system is that routine maintenance can be carried
out without any service interruption to users. MySQL Cluster achieves this through its shared
nothing architecture, and in this recipe we will show how to restart the three types of nodes
online (without taking the cluster down as a whole).