The Aleph Toolkit: Support for Scalable Distributed Shared Objects

The shared object model is an appealing programming abstraction for distributed computing. By hiding the details of the network and data distribution, it allows the programmer to focus on higher-level concerns, and makes the program structure robust in the presence of changes in distribution patterns or environment. Nevertheless, it is not at all clear that the distributed shared object model can be adapted to the needs of modern large-scale distributed applications. The Aleph Toolkit is a collection of Java packages intended to support the construction of distributed shared objects in a way that addresses networking-related performance issues. This paper describes the design and rationale for the Aleph API, as well as our preliminary experience implementing a distributed shared object system in Java. This work is supported by AFOSR Agreement F30602-96-2-0228, DARPA Order D885.