PAPER Special Issue on Next Generation Photonic Network Technologies Proposal and Evaluation of Realization Approach for a Shared Memory System in λ Computing Environment

SUMMARY In this paper, we propose a new computing en-vironment (which we will refer to λ computing environment) that provides a base for parallel computing among nodes distributed in the wide area. In our concept, virtual channels are provided utilizing optical networks connecting computing nodes. It can of-fer high-speed and reliable connection pipe among nodes, so that it is efficiently applicable to SAN (Storage Area Network) and/or Grid computing. In the environment, shared memory is consti-tuted on a virtual ring of the photonic network. Consequently, it is not necessary to distinguish shared memory in a wide-area distributed system from a communication channel; thus high-speed data exchange between computing nodes on the ring can be achieved. The key to realizing such a computing environment is how to construct a shared memory system on the photonic ring. In this paper, we propose and evaluate a shared memory system suitable to the virtual optical ring network, which takes into account contention resolution, cache coherency, and synchro-nization methods because the propagation delays among nodes are much larger than the conventional shared memory system. Through simulation experiments of using three benchmark pro-grams as representative parallel computing applications, we show the applicability of our shared memory system on the wide-area virtual photonic ring