Sang Boem Lim

GridFTP and parallel TCP support in naradabrokering

Many of the key features of file transfer mechanisms like reliable file transferring and parallel transferring are developed as part of the service. It makes very hard to re–use the same code for the different systems. We are trying to overcome this disadvantage by decoupling useful features of file transfer mechanisms from the implementation of the service and protocol, and instead placed into the messaging substrate. We may thus treat file transfer operations as a specific usage case for a more general messaging environment. This will allow us to provide file transfer quality of service to other file transfer tools that does not have same features.

Collective communications for scalable programming

HPJava is an environment for scientific and parallel programming using Java. It is based on an extended version of the Java language. One feature that HPJava adds to Java is a multi-dimensional array, or multiarray, with properties similar to the arrays of Fortran. We are using Adlib as our high-level collective communication library. Adlib was originally developed using C++ by the Parallel Compiler Runtime Consortium (PCRC). Many functionalities of this high-level communication library is following its predecessor. However, many design issues are reconsidered and re-implemented according to Java environment. Detailed functionalities and implementation issues of this collective library will be described.

A low–level communication library for java HPC

Designing a simple but powerful low-level communication library for Java HPC environments is an important task. We introduce new low-level communication library for Java HPC, called mpjdev. The mpjdev API is designed with the goal that it can be implemented portably on network platforms and efficiently on parallel hardware. Unlike MPI which is intended for the application developer, mpjdev is meant for library developers. Application level communication may be implemented on top of mpjdev. The mpjdev API itself might be implemented on top of Java sockets in a portable network implementation, or-on HPC platforms-through a JNI (Java Native Interface) to a subset of MPI.

Applications of HPJava

We describe two applications of our HPJava language for parallel computing. The first is a multigrid solver for a Poisson equation, and the second is a CFD application that solves the Euler equations for inviscid flow. We illustrate how the features of the HPJava language allow these algorithms to be expressed in a straightforward and convenient way. Performance results on an IBM SP3 are presented.

Runtime support for scalable programming in Java

Abstract The paper research is concerned with enabling parallel, high-performance computation—in particular development of scientific software in the network-aware programming language, Java. Traditionally, this kind of computing was done in Fortran. Arguably, Fortran is becoming a marginalized language, with limited economic incentive for vendors to produce modern development environments, optimizing compilers for new hardware, or other kinds of associated software expected of by today’s programmers. Hence, Java looks like a very promising alternative for the future. The paper will discuss in detail a particular environment called HPJava. HPJava is the environment for parallel programming—especially data-parallel scientific programming—in Java. Our HPJava is based around a small set of language extensions designed to support parallel computation with distributed arrays, plus a set of communication libraries. A high-level communication API, Adlib, is developed as an application level communication library suitable for our HPJava. This communication library supports collective operations on distributed arrays. We include Java Object as one of the Adlib communication data types. So we fully support communication of intrinsic Java types, including primitive types, and Java object types.

Collective communication for the HPJava programming language

This paper addresses functionality and implementation of a HPJava version of the Adlib collective communication library for data parallel programming. We begin by illustrating typical use of the library, through an example multigrid application. Then we describe implementation issues for the high‐level library. At a software engineering level, we illustrate how the primitives of the HPJava language assist in writing library methods whose implementation can be largely independent of the distribution format of the argument arrays. We also describe a low‐level API called mpjdev, which handles basic communication underlying the Adlib implementation. Finally we present some benchmark results, and some conclusions. Copyright