A grid middleware for distributed Java computing with MPI binding and process migration supports

"Grid" computing has emerged as an important new research field. With years of efforts, grid researchers have successfully developed grid technologies including security solutions, resource management protocols, information query protocols, and data management services. However, as the ultimate goal of grid computing is to design an infrastructure which supports dynamic, cross-organizational resource sharing, there is a need of solutions for efficient and transparent task re-scheduling in the grid. In this research, a new grid middleware is proposed, called G-JavaMPI. This middleware adds the parallel computing capability of Java to the grid with the support of a Grid-enabled message passing interface (MPI) for inter-process communication between Java processes executed at different grid points. A special feature of the proposed G-JavaMPI is the support of Java process migration with post-migration message redirection. With these supports, it is possible to migrate executing Java process from site to site for continuous computation, if some site is scheduled to be turned down for system reconfiguration. Moreover, the proposed G-JavaMPI middleware is very portable since it requires no modification of underlying OS, Java virtual machine, and MPI package. Preliminary performance tests have been conducted. The proposed mechanisms have shown good migration efficiency in a simulated grid environment.postprin

A Grid Middleware for Distributed Java Computing with MPI Binding and Process Migration Supports

The maintenance of infrastructure subject to aging in harsh environments demands the highest level of confidence in nondestructive evaluation. One of the most critical issues in the inspection of gas transmission pipelines remains the detection of stress corrosion cracking (SCC). The magnetic flux leakage (MFL) method [1] is widely used to detect cracks in steel. Numerical simulation using the finite element method (FEM) has been proven to be an efficient and inexpensive means of studying the interaction and redistribution of electromagnetic fields [2]. This article describes a stress corrosion crack model and its implementation in a finite element code for simulation of magnetic flux leakage inspection. For a complicated, minimal density of the mesh is desired to implement a code with reasonable requirements of computer memory and computation time. On the other hand, simulations need to be accurate enough to be experimentally validated. Traditional FEM assumes, that all the properties of materials are constants within each element. An approach with conductivity and permeability, varying within elements around a crack, is developed in this paper