more resources & better efficiency more and better scientific outcome
The unified theory of Kuiper-belt and Oort-cloud formation: experiences from porting to EGEE
Jan Astalos
Institute of Informatics
Slovak Academy of Sciences
Oort: Application details
Collaboration
Slovakia: Astronomical institute, Slovak Academy of Sciences
Italy: INAF-Catania Astrophysical Observatory
Poland: Astronomical Observatory of the A.Mickiewicz University
Main goal
Working out unified theory of the formation of:
Kuiper belt and Scattered Disc
populations of small bodies beyond the Neptune’s orbit
Oort cloud
very distant cometary reservoir
Method
simulation of the dynamical evolution of a large number (~10000) planetesimals (treated as test particles) in the proto-planetary disc; the trajectories of the particles are influenced by the perturbing forces from the giant planets, Galactic tide, and stars passing near or through the Oort cloud
Oort: More details
Computational methods:
Numerical integration of orbits using RADAU integrator (included in public available package MERCURY developed by J. Chambers)
Stellar perturbations – using advanced impulse approximation (proposed by P.A. Dybczynski)
As simple as possible – to minimise maintenance effort
Existing tools
not easy-to-use or too much application specific
We made use of pilot jobs
Concept used in production by some of the virtual organisations in EGEE
Input data are not associated with job, downloaded when pilot job starts running on worker node
Failed and waiting jobs can be simply discarded
Grid and Databases BaSTI as a practical example
Giuliano Taffoni, Santi Cassisi
INAF – Istituto Nazionale di Astrofisica
DB in EGEE Grid
Integration of DB in Grid recognized as a core research activity
Some tools/services developed for this purpose:
AMGA : a flexible and fast tool to store and access metadata. Well integrated in the M/W stack it is stable and fast although focused on metadata (but it is rapidly evolving…)
OGSA-DAI project addresses the data virtualization and focuses on data services implementation. It offers a set of Grid information system interfaces able to locate and to interact with JDBC adapter.
G-DSE is based on the idea that actual middleware implementation used to access computational resources can be also used to access DBs. It is fully integrated with LFC and supports GSI and SSL (Secure Sockets Layer)
GRelC service provides both basic and advanced primitives to transparently get access, query, manage and interact with different data sources. It is based on gSOAP and designed on a client/server idea.
BaSTI
BaSTI (a Bag of Stellar Tracks and Isochrones) database is a theoretical astrophysical catalogue that collects fundamental data sets involving stars formation and evolution.
Stellar evolution theory provides the main tool to constrain a galaxy Star Formation History from observations of its integrated magnitudes and spectra; it enables us to predict spectral and photometric properties of stellar populations of varying ages and initial chemical compositions
The relational database of evolutionary predictions fulfils the following three main criteria for a reliable and homogeneous stellar evolution library:
the input physics employed in the model computations is the most up-to-date;
models for all initial chemical compositions are computed with the same evolutionary code and the same physical framework;
models and isochrones reproduce a large array of empirical constraints obtained from observations of single stars and local resolved stellar populations.
Recently, the capabilities and relevance of the BaSTI archive have been largely increased by including an extended set of population synthesis models that allow the study of the integrated colours and magnitudes of far, unresolved stellar systems
It is however evident that the potentialities, availability and possible extension of this database, as those of any data set, are strongly hampered by the capabilities of the hardware and software framework supporting the archive.
In this context, it is now clear that the possibility to implement the BaSTI archive and the whole theoretical framework related to it within the Grid system, would open fully not-exploited possibilities of development.
FRANEC and Grid
FRANEC: a Fortran 77 code that simulates the evolution of a star on the basis of a number of different physical inputs and parameters
Benefits coming from the Grid:
More computational resources
Other Grid-intrinsic added values: e.g. distribution of datasets over different sites no single points of failure
FRANEC-Grid Interactions
FRANEC in gLite Environment
FRANEC simulation software requires the creation of some specific services on gLite general environment used to run both a SMR (Synthetic Model Run) or a FIR (Full Isochrone Run)
Runs take place through subsequent steps:
Deployment of the Simulation code on the Grid (copy the compressed code on the Grid using LFC)
Creation of an application specific environment on top of the User Interface (UI). A set of scripts allow users to configure a pipeline and submit it to the Grid
When running a FIR, we use the parametric jobs execution capability offered by the WMS to parametrize jobs in terms of initial mass and/or metallicity
The JDL file is configured with some standard ”requirements” based on the GlueSchema
FRANEC in gLite Environment
secure and easy access to stored models produced by previous simulations shall also be possible
A set of metadata is used to identify the parameters and to associate each of these parameters to the corresponding file location in the Grid (to its SURL)
AMGA is used to handle metadata service
e.g. If an EOS already exists on the Grid, the EOS jobs are not submitted but the FRANEC job is configured to download the EOS from the Grid
The final step to fully integrate the EGEE Grid Environment and the Astronomical Community Portal “BaSTI” implies the possibility to automatically update the BaSTI DB when a new simulation is available, being the BaSTI DB an external, independently managed entity.
We decide to test the G-DSE service to access the DB from the Grid.
FRANEC-Grid: Application Workflow
Auger: Use of the EGEE Grid for production of libraries with cosmic rays showers simulated using the CORSIKA program with the EPOS model
Auger: Use of the EGEE Grid for production of libraries with cosmic rays showers simulated using the CORSIKA program with the EPOS model
Port in Grid of the Astro-Wise Environment and usage of part of it for the LOFAR long-term archive
HERSCHEL Data Reduction
Applications developed by the French A&A Community in EGEE:
Evolution of the interstellar medium and stars formation through the family of PDR (Photo-Dissociation Regions); they compute in a consistent way the UV radiative transfer, the chemistry and thermal balance arising in molecular interstellar gas.
Modeling of the very high energy (VHE; E > 100GeV) γ-ray emission and multi-wavelength data from AGN (Active Galactic Nuclei).
Simulations aimed at studying the stability of the Solar System.
A&A SSC Proposal
C. Vuerli (1,2) and F. Pasian (1,2)
On behalf of the EGEE-NA4 A&A Cluster
and of the A&A SSC Editorial Board
(1) INAF – Astronomical Observatory of Trieste (2) INAF – Information System Unit
EGI and the A&A Community
EGEE-III ends in April 2010 and the new EGI is now under construction
A&A community in EGEE-III with its applications demonstrated that the Grid could be the right technology for a large fraction of applications
A&A therefore is now moving toward a dedicated SSC whose setup is in progress
An Editorial Board for A&A SSC has been formed and now the scientific tasks and activities to be carried out in EGI are under definition
Users need to be trained when approaching the problem of gridifying their applications. Training may concern general aspects concerning the Grid technology as well as specific aspects related to A&A
Tools: A&A specific training events organized within the A&A SSC; exploitation of training opportunities offered by EGI.eu and by NGIs.
Dissemination
Users should be aware of opportunities coming from the Grid technology for their scientific activity
Tools: publicize results achieved within the SSC in workshops and conferences, through any other communication mean; identification of use cases and demonstrator applications could help in this case
Lessons learned in EGEE-III
Easy ways to access and use the Grid
Often users are reluctant to approach the Grid as they perceive the technology tricky and complicated to use. Basic interfaces like CLIs don’t help in this case
Tools: Portals and Science Gateways can be decisive in overcoming this psychological barrier; Science Gateways in particular are emerging as a key tool for all communities engaged in the process of building their SSCs; they have the great advantage of collecting and organizing in a harmonized fashion: on-line training, dissemination material, applications, services… and all this easily accessible by final users
Lessons learned in EGEE-III
Improve the synergy with other technologies (HPC and the VObs)
A&A community almost equally resort to HPC and Grid to procure computational resources. Interoperability between these technologies is important if our objective is an operational environment where users transparently make use of resources for their work. For this reason PRACE (ESFRI) is one of the most important projects that could establish a partnership with our SSC.
The VObs is an example of Virtual Community that developed its Science Gateways through a suite of tools and Services. Interfaces connecting the A&A SSC and the VObs are strategic.
Interoperability requires two fundamental services: Science Gateways and tools allowing to create and manage workflows where resources of different nature are intermixed.
ESFRI Projects
Try to involve big A&A projects that could benefit from the Grid. Tight relationships with ESFRI projects are strongly encouraged for any SSC
The current ESFRI projects recognized as relevant for A&A are:
E-ELT (Extremely Large Telescope): the follow-up project of the current generation of optical telescopes. With segmented mirrors and built-in adaptive optics, it is feasible to build a 40-m class telescope
SKA (Square Kilometer Array): the SKA will have a collecting area of one million square meters distributed over a distance of at least 3000 km. This area, necessary to collect the faint signals from the early universe, will result in a 100 times higher sensitivity compared to existing facilities. The radically new concept of an “electronic” telescope will allow very fast surveys
CTA (Cherenkov Telescope Array): the pioneering Cherenkov telescopes HESS and MAGIC have observed a multitude of gamma ray sources both in our galactic centre and outside our galaxy. The CTA will greatly extend the reach of these two projects and allow for further exciting scientific discoveries
PRACE (Partnership for Advanced Computing in Europe): an European strategic approach to high-performance computing. It concentrates the available resources in a limited number of world-class top-tier centers in a single infrastructure connected to national, regional and local centers, forming a scientific computing network to utilize the top-level machines
Tools/Services: Summary
Moreover…
Moving bunches of data on the Grid
Code deployment on the Grid
Storing intermediate data produced by applications on Storage Elements
Storing/Retrieving data to/from the Grid
Grid compliant driver for CFITSIO Library
References
EGEE-III Home
http://www.eu-egee.org/
EGI Home
http://web.eu-egi.eu/
EGEE-III Astronomy and Astrophysics Cluster (Have a look in particular to QRs where significant activity within A&A is reported)
