System nodes

The system runs with multiple nodes. Nodes are assigned different roles, labels, and their state might change.

Physical nodes are contained in enclosures, hence their location in the system is presented as enclosureX.nodeY. The system can be configured with one node size (large) that has 64 TB of raw storage. Each enclosure contains four nodes of the same size. If you buy the base Lenovo system, it contains two enclosures, four nodes each.

Three nodes in a system are always assigned a control role and these three nodes are designated as a Control Plane. Another three nodes are assigned a worker role and they are used to run the services in your cluster. The remaining two nodes in the base system do not have any role assigned by default.

Worker nodes can also be assigned a label, which might then be used by Cloud Pak for Data to define which service to run on a labeled node.

The combination of a role and a label is called node personality. Nodes can have the following personalities:

Table 1. Node personalities
Node personality	Personality reported by platform manager	Description
Control Node	`control`	Three servers in a system are always assigned a control role and these three nodes are designated as a Control Plane. These servers are candidates for a Platform Manager hub. They host one Control Virtual Machine. The control plane nodes manage your cluster and your Cloud Pak for Data deployment. At least two of the three control nodes must be operational for the system to work.
Worker Node - Universal	`worker`	Compute node. Can host one or more Cloud Pak for Data Worker Virtual Machines. Can host any service, container, or pod as designated by Cloud Pak for Data.
Worker Node - Labeled	`worker <labelX>`	Compute node. A dedicated VM to host only a specific pod or application designated by Label.
Db2® Warehouse Node	`DB2WH`	A node dedicated to host Db2 Warehouse SMP in Red Hat® OpenShift®.
NPS Node	`NPS`	Compute node dedicated to Netezza Performance Server Note: Nodes in this role are not managed by Platform Manager, hence their state is always UNMANAGED.
Unset Node	`Unset`	A node with no personality assigned.

Nodes are monitored by Platform Manager, which informs you of the state that the node is in. Node state can be changed manually, or automatically by Platform Manager.

The nodes are named after their enclosure and index. The first four nodes are e1n1, e1n2, e1n3, and e1n4. The second enclosure contains the next four nodes: e2n1, e2n2, e2n3, and e2n4. The index portion of the node names are always relative to their enclosure.

Two virtual machines are hosted on the control plane nodes: e1n1-master and e1n1-ldap.

You can use the ap node command to view information about the nodes in your system, manage the node states, and assign personalities.