Thierry Delaitre

GEMLCA: Running Legacy Code Applications as Grid Services

There are many legacy code applications that cannot be run in a Grid environment without significant modification. To avoid re-engineering of legacy code, we developed the Grid Execution Management for Legacy Code Architecture (GEMLCA) that enables deployment of legacy code applications as Grid services. GEMLCA implements a general architecture for deploying legacy applications as Grid services without the need for code re-engineering, or even access to the source files. With GEMLCA, only a user-level understanding is required to run a legacy application from a standard Grid service client. The legacy code runs in its native environment using the GEMLCA resource layer to communicate with the Grid client, thus hiding the legacy nature of the application and presenting it as a Grid service. GEMLCA as a Grid service layer supports submitting jobs, getting their results and status back. The paper introduces the GEMLCA concept, its life cycle, design and implementation. It also presents as an example a legacy simulation code that has been successfully transformed into a Grid service using GEMLCA.

High-level grid application environment to use legacy codes as OGSA grid services

One of the biggest obstacles in the wide-spread industrial take-up of grid technology is the existence of a large amount of legacy code that is not accessible as grid services. The paper describes a new approach (GEMLCA: grid execution management for legacy code architecture) to deploy legacy codes as grid services without modifying the original code. Moreover, we show a workflow execution oriented grid portal technology (P-GRADE portal) by which such legacy code based grid services can be applied in complex business processes. GEMLCA has been implemented as GT-3 services but can be easily ported into the new WSRF grid standards.

GEMLCA: grid execution management for legacy code architecture design

The grid execution management for legacy code architecture (GEMLCA) describes a solution for exposing and executing legacy applications through an OGSI grid service. This architecture has been introduced in a previous paper by the same authors where the general concept was demonstrated by creating an OGSI/GT3 version of the MadCity traffic simulator. The class structure of the architecture is described presenting each component and describing the relationships between them. Also, the current architecture implementation is evaluated through test results gained by running the MadCity traffic simulator as a C/PVM legacy application.

Automatic Service Deployment Using Virtualisation

Manual deployment of the application usually requires expertise both about the underlying system and the application. Automatic service deployment can improve deployment significantly by using on-demand deployment and self-healing services. To support these features this paper describes an extension the globus workspace service. This extension includes creating virtual appliances for grid services, service deployment from a repository, and influencing the service schedules by altering execution planning services, candidate set generators or information systems.

A graphical toolset for simulation modelling of parallel systems

In this paper, a simulation model for incorporation within a performance-oriented parallel software development environment is presented. This development environment is composed of a graphical design tool, a simulation facility, and a visualisation tool. Simulation allows parallel program performance to be predicted and design alternatives to be compared. The target parallel system models a virtual machine composed of a cluster of workstations interconnected by a local area network. The simulation model architecture is modular and extensible which allows re-configuration of the platform. The model description and the validation experiments which have been conducted to assess the correctness and the accuracy of the model are also presented.

Traffic Simulation in P-Grade as a Grid Service

Grid Execution Management for Legacy Code Architecture (GEMLCA) is a general architecture to deploy existing legacy applications as Grid services without re-engineering the original code. Using GEMLCA from the P-Grade portal, legacy code programs can be accessed as Grid services and even participate in complex Grid workflows. The parallel version of MadCity, a discrete time-based traffic simulator, was created using P-Grade. This paper describes how MadCity is offered as a Grid service using GEMLCA and how this solution is embedded into the P-Grade portal.

Publishing and Executing Parallel Legacy Code Using an OGSI Grid Service

This paper describes an architecture for publishing and executing parallel legacy code using an OGSI Grid service. A framework is presented that aids existing legacy applications to be deployed as OGSI Grid services and the concept is demonstrated by creating an OGSI/GT3 version of the Westminster MadCity traffic simulator application. This paper presents the Grid Execution Management for Legacy Code Architecture (GEMLCA), and describes the progress and achievements of its implementation.

Application of Grid computing for designing a class of optimal periodic nonuniform sampling sequences

Designing periodic nonuniform sampling sequences for digital alias free signal processing is a computationally extensive problem where sequential single computer based solutions could easily run for days or even weeks. In order to reduce computation time, the sequential algorithm needed to be parallelized making it possible to execute parts of the calculations on different nodes of a computational Grid at the same time, reducing the overall runtime of the application. This paper presents and compares two different Grid based implementations representing the two main Grid approaches at the moment. The first solution utilizes a production Grid environment based on GEMLCA and the P-Grade Grid portal, and the second represents a BOINC desktop Grid-based solution.

Experiences with deploying legacy code applications as grid services using GEMLCA

One of the biggest obstacles in the wide-spread industrial take-up of Grid technology is the existence of a large amount of legacy code programs that is not accessible as Grid Services. On top of that, Grid technology challenges the user in order to intuitively interconnect and utilize resources in a friendly environment. This paper describes how legacy code applications were transformed into Grid Services using GEMLCA providing a user-friendly high-level Grid environment for deployment, and running them through the P-GRADE Grid portal. GEMLCA enables the use of legacy code programs as Grid services without modifying the original code. Using the P-GRADE Grid portal with GEMLCA it is possible to deploy legacy code applications as Grid services and use them in the creation and execution of complex workflows. This environment is tested by deploying and executing several legacy code applications on different sites of the UK e-Science OGSA testbed.

EDPEPPS: A Toolset for the Design and Performance Evaluation of Parallel Applications

This paper describes a performance-oriented environment for the design of portable parallel software. The environment consists of a graphical design tool based on the PVM communication library for building parallel algorithms, a state-of-the-art simulation engine, a CPU characteriser and a visualisation tool for animation of program execution and visualisation of platform and network performance measures and statistics. The toolset is used to model a virtual machine composed of a cluster of workstations interconnected by a local area network. The simulation model used is modular and its components are interchangeable which allows easy re-configuration of the platform. Both communication and CPU models are validated.