Propagating Updates in Asymmetric Communication Environment
Anil Gurijala, Udo W. Pooch · 1996
In this paper, we study various issues associated with maintaining consistency in asymmetric communication environment. In this environment, the bandwidth available from clients to the server is very small compared to that in the opposite direction. Therefore, data pages are broadcast periodically by the server. To minimize the page access time, pages are frequently cached at clients. When these pages are updated at the server, inconsistency arises among these copies. To maintain consistency, the updated pages must be broadcast. The update pages are scheduled based on their demand. We derive condition for scheduling for the optimal mean access time. Propagation and invalidation are the two schemes that are used in the traditional client-server based systems. We study various issues that arise due to using these schemes in asymmetric environment. We propose a scheme to tolerate communication errors while propagating updates.