Summary: Fine­Grained Mobility in the Emerald System
Eric Jul, Henry Levy, Norman Hutchinson, and Andrew Black
Department of Computer Science
University of Washington
Seattle, WA 98195
Abstract
Emerald is an object­based language and system designed for the construction of dis­
tributed programs. An explicit goal of Emerald is support for object mobility; objects in
Emerald can freely move within the system to take advantage of distribution and dynamically
changing environments. We say that Emerald has fine­grained mobility because Emerald ob­
jects can be small data objects as well as process objects. Fine­grained mobility allows us to
apply mobility in new ways but presents implementation problems as well. This paper dis­
cusses the benefits of fine­grained mobility, the Emerald language and run­time mechanisms
that support mobility, and techniques for implementing mobility that do not degrade the
performance of local operations. Performance measurements of the current implementation
are included.
1 Introduction
Process migration has been implemented or described as a goal of several distributed systems
[19, 13, 15, 18, 7, 23, 8]. In these systems, entire address spaces are moved from node to node.
For example, a process manager might initiate a move to share processor load more evenly, or

Source: Anderson, Richard - Department of Computer Science and Engineering, University of Washington at Seattle

Collections: Computer Technologies and Information Sciences