The data node is the standard vRealize Operations role, and is the default when adding a new node into an existing cluster. It provides the core functionality of collecting and processing data and data queries, as well as extending the vRealize Operations cluster by being a member of the GemFire Federation that, in turn, provides the horizontal scaling of the platform.
As shown in the following diagram, a data node is almost identical to a master/master replica node, with the exception of the Central vPostgres database, NTP server, and GemFire locator:
