Decentralized Replication Mechanisms in Deno

We are currently finalizing the design of Deno, a new shared-object system intended for use with repli-cated mobile and wide-area data. The broad aim of our research is to develop a framework for highly-available, decentralized shared-object protocols. The key idea is that our protocols will support high availability through a distributed voting scheme. Specifically, we will investigate (a) peer-to-peer up-dates, which will allow incremental progress to be made in the absence of full connectivity between com-ponent servers, (b) voting rather than centralized schemes for committing updates, ensuring that no sin-gle point of failure can prevent updates from being committed, and (c) application-specific consistency control, allowing applications to relax coherency constraints in ways that do not break the application's notion of consistency. Distribution and multiple connectivity modes are becoming the norm rather than the exception in current computing environments. Thus, we expect the impact of our research to be felt in areas as disparate as mobile computing and collaborative data warehousing on the Internet. (Also cross-referenced as UMIACS-TR-98-54