To support scaling of existing clusters into large clusters and improve control message performance, Vertica delegates control message responsibilities to a subset of Vertica nodes, called control nodes. Control nodes communicate with each other. Other cluster nodes are assigned to a control node, which they use for control message communications.
Control nodes on large clusters
On clusters of 120 or more nodes, a large cluster layout is necessary and enabled by default. Vertica makes automatic control node assignments unless you use one of the following options:
|If you want to ...||Do this|
|Install a new cluster before you create a database||
Run the Vertica installation script with the
||Use cluster management functions described in Defining and Realigning Control Nodes on an Existing Cluster.|
|Influence the placement of control nodes in your cluster's physical layout||Define fault groups to configure Vertica for your cluster. See Fault Groups for details.|
Control nodes on small clusters
If your cluster has fewer than 120 nodes, large cluster is neither necessary nor automatically applied. As a result, all nodes are control nodes. However, Vertica lets you define control nodes on any sized cluster. Some environments, such as cloud deployments that might have higher network latency, could benefit from a smaller number of control nodes.