dCache: from Resilience to Quality of Service

A major goal of future dCache development will be to allow users define file Quality Service (QoS) in a more flexible way than currently available. This mean implementing what might called QoS rule engine responsible for registering and managing time-bound transitions files or storage units. In anticipation this extension existing capabilities, the Resilience service, which maintains on-disk replica state, needs undergo both structural modification generalization. paper describes ongoing work transform into new architecture eventually support broadly defined QoS.