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EGEE Middleware: gLite Information Systems (IS). EGEE Tutorial ISGC 2007, Taipei March 26, 2007. Agenda. Introduction LDAP Glue Schema IS Components GRIS GIIS BDII IS Query Tools IS Practical. Overview of gLite Middleware. How is Information Systems Used?.
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EGEE Middleware:gLite Information Systems (IS) EGEE Tutorial ISGC 2007, Taipei March 26, 2007
Agenda • Introduction • LDAP • Glue Schema • IS Components • GRIS • GIIS • BDII • IS Query Tools • IS Practical
How is Information Systems Used? If you are a middleware developer Workload Management System: Matching job requirements and Grid resources Monitoring Services: 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 a user Retrieve information about resources • where you can run your job • where you can copy your files If you are site manager or service You “publish” the information about the services you provide.
gLite: MDS Information System • gLite adopted the Globus Monitoring and Discovery Service as it’s Information System • The build blocks include • LDAP protocol as the access protocol • Glue Schema to define the format of the information • Architecture and Components • GRIS • GIIS • BDII
Lightweight Directory Access Protocol • Network protocol designed for querying and modifying directory services • Structures directory entries as a tree: Directory Information Tree (DIT) • Following a path from the node back to the root of the DIT • a unique name is built (the DN): “id=pml,ou=IT,or=CERN,st=Geneva, \ c=Switzerland,o=grid” o = grid (root of the DIT) c= US c=Switzerland c=Spain st = Geneva or = CERN ou = IT ou = EP objectClass:person cn: Patricia M. L. phone: 5555666 office: 28-r019 id = pml id=gv id=fd
Components of the IS Top-level BDII: collects information from GIISs At each site: a site GIIS(site BDII): collects information from local GRISs On each resource a GRIS: Publishes dynamic and static information Abbreviations: BDII: Berkeley DataBase Information Index GIIS: Grid Index Information Server GRIS: Grid Resource Information Server
GRISs, GIISs and BDII connections User Application WMS Monitoring Services BDII-B BDII-A CE Site GIIS CE Site GIIS CE Site GIIS LFC Local GRIS CE Local GRIS SE Local GRIS SE Local GRIS RB Local GRIS CE Local GRIS CE Local GRIS SE Local GRIS MyProxy Local GRIS
Querying the IS Two sets of commands: • lcg-infosites: simple, meets most needs • lcg-info: supports more complex queries
LCG Information Service • a user or a service can query • the BDII (usual mode) • LDAP servers on each site
PRACTICAL • This introduces use of the commands to access the information system • You will be exploring the GILDA grid, seeing what computing elements and storage elements exist. • Please go to the link for this practical.