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Pleiad is a research prototype providing object based shared memory abstraction across physically distributed computing resources. These resources include high performance clusters, networks of workstations, as well as mobile and embedded devices. Being based on the Java platform at library level, Pleiad forms a fully portable and interoperable middleware, targeting simultaneously on simplified multithreaded programming and efficient execution of highly concurrent applications. Pleiad incorporates the advances introduced with the Java major update 5, as well as the most recent version 6, having no native bindings in its code. At the same time it does not introduce any supplementary tools to alter the bytecode of the application nor it extends the semantics of the language. Its functionality can be utilized in the same way as it happens with every collection that is provided through the Java library.

Design Issues

Considering that the performance of higly concurrent applications is based on their ability to adapt during execution, especially when such applications are destined to run on diverse and mobile environments such as grids and clusters, we have designed Pleiad so that it incorporates the necessary features that will allow applications to adapt during run-time. In order to provide several alternative implementations for the various mechanisms, the architecture of Pleiad is quite modular and expandable in a straightforward way. It follows a layer architecture that is able to separate the building blocks of the middleware and provide the necessary abstraction to the programmer of the multithreaded application.

People Involved

Elefterios D. Polychronopoulos (Faculty)
Konstantinos I. Karantasis (PhD student)
Konstantinos I. Menychtas (MSc student)

Naming Trivia

The name Pleiad is derived from the Greek work Πλειάδα which is usually used to refer to a group of people with exceptional performance on a certain activity. In that spirit Pleiad was the name of a group of seven Alexandrian poets of the 3rd century B.C. and after them fourteen French poets of the Renaissance (7 men and 7 women) named also their group Pléiade. Accordingly, the current research project aims to deploy a "Πλειάδα" of threads with exceptional performance as well :)