Lazy replication: exploiting the semantics of distributed services

摘要: The need for high availability in distributed services requires that the data managed by service be replicated. A major challenge managing replicated is ensuring consistency among copies of data. One way to guarantee force operations take effect same order at all sites. This approach, however, often expensive. novel method designed constructing logically centralized, highly available used a environment. intended appear clients centralized: spite service's implementation, it has observable behavior as single copy. semantics application implemented taken into account weaken implementation constraints and thus improve response time increase availability; can relaxed long cannot observe difference. To illustrate how relax on operation orders, an electronic mail system considered. based partially ordered discussed. >