Implementing Replica Placements: Feasibility and Cost Minimization
Thanasis Loukopoulos, Nikos Tziritas, Petros Lampsas, Spyros Lalis · 2007
Given two replication schemes Xoldand Xnew, the replica transfer scheduling problem (RTSP) aims at reaching Xnew, starting from Xold, with minimal implementation cost. In this paper we generalize the problem description to include special cases, where deadlocks can occur while in the process of implementing Xnew. We address this impediment by introducing artificial (dummy) transfers. We then prove that RTSP-decision is NP-complete and propose two kinds of heuristics. The first attempts to replace dummy transfers with valid ones, while the second minimizes the implementation cost. Experimental evaluation of the algorithms illustrates the merits of our approach.