Methods, apparatus and computer programs are described for monitoring resources within a data processing network. Monitoring entities can be selected, and a set of active monitoring functions can be modified, based on the requirements of consumers of monitored data. A first method involves monitoring resources on behalf of consumer entities within the network. A description of the consumer entity's monitoring requirements are published by the consumer entity and stored in a repository. The monitoring requirements of the consumer entity are compared with the monitoring capabilities of a plurality of monitoring entities, to identify a monitoring entity capable of satisfying the monitoring requirements of the consumer entity. An identified monitoring entity is selected, and a connection is established between the selected monitoring entity and the consumer entity. A second method involves modifying an active set of monitoring functions in response to changes to monitoring requirements of a currently active set of consumer entities.