Java communications for large-scale parallel computing

Java has many features of interest to developers of large-scale parallel applications. At the same time, there are currently several barriers to the effective use of Java in this area. In this article we present part of the results and proposed solutions to these problems. In particular, we report about the current status of the organized collaborations within the Java Grande Forum in the area of Message Passing for Java (MPJ) and faster Remote Method Invocation (RMI). An outline of the current MPJ specification is given along with a discussion of several open issues and performance results on different platforms - Linux cluster, IBM SP-2, and Sun E4000. These “proof-of-concept” results are quite encouraging for future developments and efforts in this area. We also demonstrate that a much faster drop-in RMI and an efficient serialization can be designed and implemented in pure Java. Our benchmark results show that this better serialization and improved RMI design and implementation save more than 50% of the runtime in comparison to the standard implementations available at the moment. Our results demonstrate that fast parallel and distributed computing in Java is indeed possible

Debugging MPI Grid applications using Net-dbx

Problem solving using grid computing environments has become very popular amongst research groups in computation-demanding fields. This is due to the ability of Grid technologies and middleware to enable large-scale resource sharing. Application-development in such environments is a challenging process, thus the need for grid enabled development tools is also one that has to be fulfilled. In our work we describe the development of a Grid Interface for the Net-dbx parallel debugger, that can be used to debug MPI grid applications. Net-dbx is a web-based debugger enabling users to use it for debugging from anywhere in the Internet. The proposed debugging architecture is platform independent, because it uses Java, and it is accessible from anywhere, anytime because it is web based. Our architecture provides an abstraction layer between the debugger and the grid middleware and MPI implementation used. This makes the debugger easily adaptable to different middlewares. The grid-enabled architecture of our debugger carries the portability and usability advantages of Net-dbx on which we have based our design. A prototype has be developed and tested