Abstract
We discuss how to take checkpoints in object-based systems. Object-based checkpoints are consistent in the object-based system but may be inconsistent according to the traditional message-based definition.We present an asynchronous protocol for taking object-based checkpoints among objects. An object to take a checkpoint in the traditional protocol does not take a checkpoint if the current checkpoint is object-based consistent with the other objects. The number of checkpoints can be reduced by the protocol.