Two new approaches for orphan detection

In distributed systems which use RPC, if a failed process sent a request before failing, the receiver of this request becomes an orphan process and must roll back to undo the effects of receiving the message. There are two types of orphan: one of them mostly called "crash- orphan" in which client crashes. Another which causes orphan process is called abort-orphan in which parent\´s process is aborted (Baumann and Rothermel). Orphans are undesirable because they waste system resources and can make inconsistent data (Herlihy and Mckendry, 1990). In this paper initially we present two novel methods for orphan detection. Finally we compare our new methods with the older ones.