Gábor Dózsa

P-GRADE: a grid programming environment

P-GRADE provides a high-level graphical environment to develop parallel applications transparently both for parallel systems and the Grid. P-GRADE supports the interactive execution of parallel programs as well as the creation of a Condor, Condor-G or Globus job to execute parallel programs in the Grid. In P-GRADE, the user can generate either PVM or MPI code according to the underlying Grid where the parallel application should be executed. PVM applications generated by P-GRADE can migrate between different Grid sites and as a result P-GRADE guarantees reliable, fault-tolerant parallel program execution in the Grid. The GRM/PROVE performance monitoring and visualisation toolset has been extended towards the Grid and connected to a general Grid monitor (Mercury) developed in the EU GridLab project. Using the Mercury/GRM/PROVE Grid application monitoring infrastructure any parallel application launched by P-GRADE can be remotely monitored and analysed at run time even if the application migrates among Grid sites. P-GRADE supports workflow definition and co-ordinated multi-job execution for the Grid. Such workflow management can provide parallel execution at both inter-job and intra-job level. Automatic checkpoint mechanism for parallel programs supports the migration of parallel jobs inside the workflow providing a fault-tolerant workflow execution mechanism. The paper describes all of these features of P-GRADE and their implementation concepts.

A graphical development and debugging environment for parallel programs

Abstract To provide high-level graphical support for PVM (Parallel Virtual Machine) based program development, a complex programming environment (GRADE) is being developed. GRADE currently provides tools to construct, execute, debug, monitor and visualize message-passing parallel programs. It offers a high-level graphical programming abstraction mechanism to construct parallel applications by introducing a new graphical language called GRAPNEL. GRADE also provides the programmer with the same graphical user interface during the program design and debugging stages. A distributed debugging engine (DDBG) assists the user in debugging GRAPNEL programs on distributed memory computer architectures. Tape/PVM and PROVE support the performance monitoring and visualization of parallel programs developed in the GRADE environment.

Workflow Support for Complex Grid Applications: Integrated and Portal Solutions

In this paper we present a workflow solution to support graphically the design, execution, monitoring, and performance visualisation of complex grid applications. The described workflow concept can provide interoperability among different types of legacy applications on heterogeneous computational platforms, such as Condor or Globus based grids. The major design and implementation issues concerning the integration of Condor tools, Mercury grid monitoring infrastructure, PROVE performance visualisation tool, and the new workflow layer of P-GRADE are discussed in two scenarios. The integrated version of P-GRADE represents the thick client concept, while the portal version needs only a thin client and can be accessed by a standard web browser. To illustrate the application of our approach in the grid, an ultra-short range weather prediction system is presented that can be executed in a grid testbed and visualised not only at workflow level but at the level of individual parallel jobs, too.

Designing parallel programs by the graphical language GRAPNEL

Abstract We propose a new visual programming language, called GRAPNEL (GRAphical Processs NEt Language), for designing distributed parallel programs based on the message passing programming paradigm. GRAPNEL supports graphically the Process Group abstraction and the automatic generation of several regular process topology based on predefined topology templates. Dynamic process creation and destruction are possible but can be applied only in a well structured manner. GRAPNEL is a hybrid language, where the communication related parts of the program are described using graphical symbols but textual descriptions are applied where they are more appropriate. The first prototype of the GRAPNEL programming environment uses the PVM as the basis of the message passing mechanism. Textual program parts can be written in standard C. Other message passing libraries (e.g. MPI) and ordinary textual languages (e.g. FORTRAN) are to be supported in the future.

The P-GRADE Grid Portal

Providing Grid users with a widely accessible, homogeneous and easy-to-use graphical interface is the foremost aim of Grid-portal development. These portals if designed and implemented in a proper and user-friendly way, might fuel the dissemination of Grid-technologies, hereby promoting the shift of Grid-usage from research into real life, industrial application, which is to happen in the foreseeable future, hopefully. This paper highlights the key issues in Grid-portal development and introduces P-GRADE Portal being developed at MTA SZTAKI. The portal allows users to manage the whole life-cycle of executing a parallel application in the Grid: editing workflows, submitting jobs relying on Grid-credentials and analyzing the monitored trace-data by means of visualization.

The GRED graphical editor for the GRADE parallel program development environment

Abstract In this paper, we describe a graphical editor GRED as a part of the integrated programing environment GRADE that is intended to support designing, debugging and performance tuning of message-passing programs running on a heterogeneous network of computers. The GRED editor hides the cumbersome details of the underlying low-level message-passing system (which can be either PVM or MPI) by providing visual abstractions but allows the programer to define local computations of the individual processes in C (or in Fortran in the future) independently from the visually supported process management and inter-process communication activities. Visual representation of the critical (i.e. message-passing related) parts of the code can help the user in grasping the complex structure and run-time behavior of the whole parallel application, even if he or she is not an expert in the field of concurrent programing.

Associating composition of Petri net specifications with application designs in GRADE

To provide high-level graphical support for developing message passing programs, an integrated programming environment (GRADE) is being developed. GRADE currently provides tools to construct, execute, debug, monitor and visualise message-passing based parallel programs. The paper describes the extension of GRADE with formal method support based on Petri nets composition. We outline specification composition, directly associated with application composition as well as the integration of specification and implementation of program development.

A graphical programming environment for message passing programs

A number of MP interfaces are available today but one of the most popular is the PVM software package. PVM permits the user to configure his own virtual computer by hooking together a heterogeneous collection of UNIX based machines on which the user has a valid login and which are accessible over some network. To provide high-level graphical support for PVM based program development, an integrated programming environment (GRADE) is being developed. GRADE currently provides tools to construct, execute, debug, monitor and visualise message-passing based parallel programs. GRADE offers the programmer the same graphical user interface during the whole development process and high-level graphical programming abstraction mechanisms to construct parallel applications.

The GRED Graphical Editor for the GRADE Parallel Program Development Environment

In this paper, we describe a graphical editor GRED as part of the integrated programming environment GRADE that is intended to support designing, debugging and performance tuning of message-passing programs running on a heterogeneous network of computers. The GRED editor hides the cumbersome details of the underlying low-level message-passing system (which is currently the PVM system) by providing visual abstractions but allows the programmer to define local computations of the individual processes in C (or in Fortran in the future) independently from the visually supported process management and inter-process communication activities.

Enhanced monitoring in the GRADE programming environment by using OMIS

Abstract To provide high-level graphical support for developing message passing programs, an integrated programming environment (GRADE) is being developed. GRADE provides tools to construct, execute, debug, monitor and visualise message-passing based parallel programs. The paper describes the integration of GRADE and an OMIS compliant monitor system. OMIS is a recent specification of a universal on-line monitoring interface for parallel and distributed programs. The integration provides GRADE with a more flexible monitoring support and makes possible the simultaneous usage of debugging and visualisation tools. The paper specifically addresses the requirements imposed by GRADE on the on-line event tracing mechanisms, as well as their implementation and performance.