Integrating Coherency and Recoverability in Distributed Systems
Michael J. Feeley, Jeffrey S. Chase, Vivek R. Narasayya, and Henry M. Lev
Department of Computer Science and Engineering, FR-35
University of Washington
Seattle, WA 98195
{feeley,chase,nara,levy}@cs.washington.edu
Abstract
We propose a technique for maintaining coherency of a transactional
distributed shared memory, used by applications accessing a shared
persistent store. Our goal is to improve support for fine-grained
distributed data sharing in collaborative design applications, such
as CAD systems and software development environments. In contrast,
traditional research in distributed shared memory has focused on
supporting parallel programs; in this paper, we show how distributed
programs can benefit from this shared-memory abstraction as well.
Our approach, called log-based coherency, integrates coherency support
with a standard mechanism for ensuring recoverability of persistent
data. In our system, transaction logs are the basis of both
recoverability and coherency. We have prototyped log-based coherency
as a set of extensions to RVM [Satyanarayanan et al. 94], a runtime
package supporting recoverable virtual memory. Our prototype adds
coherency support to RVM in a simple way that does not require changes
to existing RVM applications. We report on our prototype and its
performance, and discuss its relationship to other DSM systems.
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