Geographical replication zones in MySQL Cluster?

Question

In a default installation, data is shared indiscriminately across all data nodes.

Is it possible to specify that certain tables can only be replicated across a specific group of data nodes?

If so, do the tables need to be created on those nodes, or can they be migrated from other nodes?

Answer 1

In MySQL Cluster tables are spread among all nodes by default. It is possible to specify a table to only reside on a subset of the node groups by either setting the number of partitions or by setting PARTITION_BALANCE (in 7.5). It is not intended to use this for geographic replication.

It is not possible to specify exactly on which node group these partitions will reside (at least I don't think, there was some work in 5.1 to provide NODEGROUP when creating partitions, but this is not fully supported, so a bit unsure what works here and what doesn't).

For geographic replication MySQL Cluster supports replication from one cluster to another cluster. This is using MySQL Replication and can thus be done selective for certain tables. It is possible to replicate different tables to different clusters by using multiple MySQL replication servers inside one MySQL Cluster.