QoS-based method for compensating multimedia objects

Distributed applications are manipulating multiple multimedia objects. QoS of an object is manipulated in addition to the state of the object. After objects are manipulated, they may need to be rolled back in order to undo the manipulation. It is not easy to take a checkpoint of the object because the state is larger and the data structure is more complex than traditional data. We discuss an approach in which the methods performed are logged instead of the states and compensating methods of the methods in the log are performed to undo the methods. In addition, it is sufficient for applications to restore a state which supports enough QoS even if the state is different from the previous one