Advanced MySQL 8

Highly available shards

Group replication has a limitation: it can work with, at most, nine servers in a group. So, if you have a higher requirement for resources, then it can be a problem. So, you can breakdown your schema in multiple shards, and each shard itself can represent a group.

Sharding is a popular approach to achieving write scale-out. Users can use MySQL group replication to implement highly available shards, and each shard can map into a replication group. This way, you can infinitely scale your system. In this case, multiple shards are responsible for taking care of the disjoint dataset.