FRANEC and Ba. STI grid integration Massimo Sponza INAF - Osservatorio Astronomico di Trieste
Grids Grid 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. g. Lite, EU funded project coordinated by EGI and EMI g. Lite is batch system grid, with schedulers an queues.
Ba. STI Bag of Stellar Tracks and Isochrones. Ba. STI 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. Ba. STI is based on relational database and have query and visualization capability.
FRANEC is the evolutionary code used to populate Ba. STI 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 Ba. STI catalogue. We decide to build an application that use a g. Lite grid.
CLI Application The firs applicatio that was developed, was based on g. Lite user interface (UI). g. Lite 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 Ba. STI database. Application have to be used by an expert user
CLI Application The 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 Application First 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 portal Extending 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 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 portal To 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, g. USE and WS-PGRADE, a web services based system where the graphical interface is separate from the services.
P-GRADE portal Another 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.
Conclusions We 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 g. USE and WS-PGRADE that combine a service-oriented architecture with modularity.
Conclusions The 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 Sponza OATs - INAF
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