A Garbage Collection of Message Logs without Additional Messages on Causal Message Logging Protocol

This paper presents a garbage collection protocol for message content logs and message determinant logs which are saved on the stable storage for fault tolerance, The previous works of garbage collections in causal message logging protocol try to solve the garbage collection of message determinant log. In order to avoid the sympathetic rollback, the process has to maintain the message content logs. But the previous works, in order to solve the garbage collection of message content logs,they needed additional messages.We propose new definitions for garbage collections conditions for message determinant logs and message content logs and the garbage collection algorithm based on the definitions, Since the proposed algorithm uses MAG(Modified Antecednce Graph), the additional messages for garbage collection is not needed. The proposed garbage collection algorithm makes'the lazy garbage collection effect',because relying on the piggy backed check point information in send/receive message. But'the lazy garbage collection effect'does not break the consistency of the whole systems and does not need additional messages for the garbage collections.