In this paper we discuss the behavior of the replacement mechanism of well-known COMA protocols applied to a loosely-coupled multicomputer system sharing a common bus. We also present VSRCOMA, a COMA protocol that uses an advanced replacement mechanism in order to select the destination node of a replacement transaction without introducing penalties due to the increase of the network traffic. Our comparative study of the behavior of different replacement mechanisms in the execution of Splash-2 programs confirm the effectiveness of the VSR-COMA protocol for this kind of systems.
Diego R. Llanos Ferraris, Benjamín Sahelice