Unified framework for policy-based metadata-driven storage services

Providing a service in a storage system includes using a predicate that corresponds to a subset of storage objects in a set of storage objects stored in the storage system. The predicate is used to select or reject the objects to which the service is to be provided. The predicate is applied to the set of storage objects to obtain the subset of storage objects. The service is then invoked for the subset of storage objects selected according to the predicate. A trigger event causes invocation of the service. The trigger event may be periodic and/or may be a storage object lifecycle event, a storage object access related event, an event corresponding to a state change of the storage system, or an event that is external to the storage system. The trigger event may include the predicate being modified.