FRANEC and BaSTI grid integration

Massimo Sponza

INAF - Osservatorio Astronomico di Trieste

GridsGrid is a computer service that allows to have

access to enormous amounts of computing and disk space resources

Grid is now a mature product.There are several grid implementation, each

one with its own distinctive characteristics.gLite, EU funded project coordinated by EGI

and EMIgLite is batch system grid, with schedulers

an queues.

BaSTIBag of Stellar Tracks and Isochrones.BaSTI is theoretical astrophysical

catalogue that collects fundamental data set involving star formation and evolution.

To create this database is necessary to run a large number of stellar evolutionary computations.

BaSTI is based on relational database and have query and visualization capability.

FRANECFRANEC is the evolutionary code used to

populate BaSTI database.FRANEC calculate a synthetic model.To compute an isochrone it is necessary to

execute a large number of synthetic model.The grid technology seems to be a good answer

to data storage and processing needs of the BaSTI catalogue.

We decide to build an application that use a gLite grid.

CLI ApplicationThe firs applicatio that was developed, was

based on gLite user interface (UI).gLite UI is command line interfaces.The application was designed for the

computation of isochrones.It can produces a large number of running

jobs that can produce a large amount of data. It was develped to produce the data to

populate BaSTI database. Application have to be used by an expert user

CLI ApplicationThe application consist of bash and per script.It uses grid services

Workload Management System (WMS) is a computing resource broker

Metadata catalogue AMGA, is a data catalogue that can service both as a directory service or as a light database

Grid strorage and Logical File Catalog (LFC).

CLI ApplicationFirst set of script manage the interaction with

the user and creation of the configuration tasks.

Second set is used to manage the interaction with the grid: job submission and monitoring.

Each SM is identified by it initial data set and this data are saved in AMGA.

Application before submitting a SM job checks whether it was already calculated.

The output file are stored in grid and have an logical file name.

P-GRADE portalExtending the use of FRANEC to less

experienced user, as for example students.To meet this needs it was opted to provide a

graphical interface.P-GRADE web portal was chosen.Web portal:

Provide graphical interface.Simplify the management of updates, being

centralized.The access tool for the user is simple browser.Expandable through modules called portlets.

P-GRADE portalP-GRADE portal is specialized for grid

interaction, both for job run and data access.The new application we developed is set of

portlets with specific functionality.For less advanced user it is possible to specify

the initial parameter of an SM and then by pressing a few buttons job is created and submitted in grid.

The poweruser may also run parametric jobs, when some parameters was supplied through an interval of value with given step.

P-GRADE portalTo develop this application it was necessary to

go down to low level technical details on some components.

This is not an optimal situation from a design and development point of view.

This problem will be solved by adopting the succesor to P-GRADE, gUSE and WS-PGRADE, a web services based system where the graphical interface is separate from the services.

P-GRADE portalAnother problem is that of digital certificates

for occasional users. The time of isue of personal certificate is to

long.This too, we hope will, be solved with the

newer version because users will be allowed to submit only SM jobs and will no longer have access to the generic job submission facility.

In this way the system will be a fully fledged service on its own, and so be able to submit jobs to the grid with its own grid certificate.

ConclusionsWe have seen that it is possible to create

applications based on the grid and that the numerical simulations are ideal candidates for these applications.

The use of graphical interfaces brings the technology, which may be complex, closer to users.

Moreover the portal is more than just a graphical interface, but a tool to create new applications due to its reusable components and provided services.

This is even more true with the gUSE and WS-PGRADE that combine a service-oriented architecture with modularity.

ConclusionsThe grid is an excellent way to provide

computing resources to occasional users. Having these resources in house would be too

expensive and wasteful.

Therefore, the use of the grid is a strategic choice.

Thanks

Massimo SponzaOATs - INAF