Abstract

Implementation of a Portable Software DSM in Java
Yukihiko Sohda - Tokyo Institute of Technology Hidemoto Nakada - Electrotechnical Laboratory Satoshi Matsuoka - Tokyo Institute of Technology Hirotaka Ogawa - Tokyo Institute of Technology
Rapid commoditization of advanced hardware and progress of networking technology is now making wide area high-performance computing a.k.a. the `Grid' Computing a reality. Since a Grid will consist of vastly heterogeneous sets of compute nodes, especially commodity clusters, some have articulated the use of Java as a suitable technology to satisfy portability across different machines. Since Java's natural model of parallelism is shared memory multithreading, one will have to support distributed shared memory (DSM) in a portable manner; however, none of the previous work on implementing Java on DSM has been a portable solution. Instead, we propose a software architecture whose goal is to achieve portability of DSM implementations across different commodity clustering platforms, while restricting the programming model somewhat, and implemented a prototype system, JDSM. Benchmark results show that the current implementation on Java incurs increased memory coherency maintenance cost compared to C-based DSMs, thus limiting scalability to some degree, and we are currently working on a solution to alleviate this cost.

Implementation of a Portable Software DSM in Java

Yukihiko Sohda - Tokyo Institute of Technology
Hidemoto Nakada - Electrotechnical Laboratory
Satoshi Matsuoka - Tokyo Institute of Technology
Hirotaka Ogawa - Tokyo Institute of Technology

Rapid commoditization of advanced hardware and progress of networking
technology is now making wide area high-performance computing a.k.a. the
`Grid' Computing a reality. Since a Grid will consist of vastly
heterogeneous
sets of compute nodes, especially commodity clusters, some have articulated
the use of Java as a suitable technology to satisfy portability across
different machines. Since Java's natural model of parallelism is shared
memory multithreading, one will have to support distributed shared memory
(DSM) in a portable manner; however, none of the previous work on
implementing Java on DSM has been a portable solution. Instead, we propose a
software architecture whose goal is to achieve portability of DSM
implementations across different commodity clustering platforms, while
restricting the programming model somewhat, and implemented a prototype
system, JDSM. Benchmark results show that the current implementation on Java
incurs increased memory coherency maintenance cost compared to C-based DSMs,
thus limiting scalability to some degree, and we are currently working on a
solution to alleviate this cost.