Information System Virginia Martín-Rubio Pascual virginia.martinrubio@rediris.es RedIRIS/Red.es Curso Grid y e-Ciencia 2010, Valencia 6- 9 Julio 2010

Glossary MDS Monitoring and Discovery Service GLUE Grid Laboratory for a Uniform Environment LDAP Lightweight Directory Access Protocol DIT Directory Information Tree BDII Berkeley Database Information Index GIIS Grid Index Information Server GRIS Grid Resource Information Service

How is Information Systems Used? If you are MIDDLEWARE DEVELOPER WMS (Workload Management System) Matching job requirements and Grid resources. Monitoring systems Retrieving information about Grid resources status and availability. What resources are available to the Grid? Computing resources Storage resources Site and services What is their current status? If you are an USER Retrieve information about resources where you can run your job where you can copy your files If you are SITE MANAGER You “publish” the information about the services you provide. Un sistema de información es aquel que recolecta y centraliza la información sobre el estado de los recursos disponibles en la Grid. Without this we would not know * what resources are available * what are their current status

BDII BDII (Berkley DataBase Information Index) BDII has been adopted in gLite middleware as the Information System provider. It´s an evolution of the Globus Monitoring and Discovering System (MDS). BDII is a distributed and hierarchical information system based on LDAP protocol (Lightweight Directory Access Protocol). The data published in the Information System (IS) conforms to the GLUE (Grid Laboratory for a Uniform Environment) Schema. Information System components: Resource GRIS Site level BDII Top level BDII

LDAP Network protocol designed for querying and modifying directory services. Structures directory entries as a tree: Directory Information Tree (DIT). Following a path from the black node to the root of the DIT a unique name is built: Distinguished Name (DN): “id=pml,ou=IT,or=CERN,st=Geneva, \ c=Switzerland,o=grid” o= grid (raíz del DIT) c= US c=Switzerland c=Spain st = Geneva or = CERN ou = IT ou = EP id = pml id=gv id=fd

GLUE: Grid Laboratory Uniform Environment GLUE Schema The data published in the Information System conforms to the GLUE. GLUE: Grid Laboratory Uniform Environment The GLUE Schema aims to define a common conceptual data model to be used for Grid resources. It is a data model to describe in a meaningful way information on grid resources (static and dynamic info): It’s based on LDAP database model. As result of a collaboration between the EU‐DataTAG and iVDGL projects. Now, GLUE Schema is being mapped to an XML representation: http://glueschema.forge.cnaf.infn.it

GLUE Schema Example

Information System Components Top-level BDII: collects information from site BDIIs At each site: a site-level BDII (site GIIS): collects information from local GRISs On each resource: a local GRIS: Publishes dynamic and static information BDII: Berkeley DataBase Information Index GIIS: Grid Index Information Server GRIS: Grid Resource Information Server

Top BDII, site BDII and GRISs connections A user or a service can query: The top BDII (usual mode) LDAP servers on each site (site BDII) - User Application - WMS - Monitoring Services Top BDII-A Top BDII-B Site 1 CE Site BDII Site 2 CE Site BDII Site 3 CE Site BDII LFC Local GRIS SE Local GRIS SE Local GRIS CE Local GRIS RB Local GRIS CE Local GRIS CE Local GRIS SE Local GRIS MyProxy Local GRIS

Information System Monitoring Gstat: Checks health of Information System at each site http://goc.grid.sinica.edu.tw/gstat

Querying the Information System BDII- MDS: ldapsearch: LDAP CLI lcg-infosites: simple, meets most needs. lcg-info: support more complex queries.

References BDII documentation gLite: User guide https://twiki.cern.ch/twiki/bin/view/EGEE/BDII https://twiki.cern.ch/twiki/bin/view/LCG/BdiiNotes gLite: User guide https://edms.cern.ch/file/722398/gLite-3-UserGuide.pdf Information System: User guide http://twiki.cern.ch/twiki/bin/genpdf/EGEE/InformationSystem GLUE Schema documentation http://glueschema.forge.cnaf.infn.it/

Thanks for your attention! Questions?