Adding nodes
Postgres-XC allows you to add new servers to the setup at any point in the process. All you have to do is set up a node as we have seen before and call CREATE NODE
on the controller. The system will then be able to use this node.
However, there is one important point about this: if you have partitioned a table before adding a new node, this partitioned table will stay in its place. Some people may expect that Postgres-XC magically rebalances this data to new nodes. User intervention is necessary for rebalancing. It is your task to move new data there and make good use of the server.
It is necessary for Postgres-XC to behave in this way because adding a new node would lead to unexpected behavior otherwise.
Rebalancing data
Since Postgres-XC 1.2, there has been a new feature in Postgres-XC. It allows you to add a server to the infrastructure during normal operations. While adding the node itself is easy, rebalancing data is not so easy.
Basically, the following command is available...