Information Services • Configuration, performance, monitoring, … , the information about the grid entities should be made available to the users /applications in a timely, consistent & easy to use manner. • An understanding of alternative designs of a Grid information service. (MDS2/LDAP/Directory services, Relational databases, and MDS3/Grid services)
MDS2/LDAP/Directory Services • Hierarchical model. • Pro: Naturally decomposes across administrative boundaries. • Con: cannot reflect complex relationships among data objects; perform poorly when frequently updates; lack of powerful query languages.
Users Apps Producer Web SOAP Registry Authentication Query Mgr. Update Mgr. Consumer Oracle 9i Relational models RGIS R-GMA
Some notes about relational models • RGIS: One server per site. representing, updating, querying. • R-GMA: one “RDBMS” per VO. It’s relational in the sense of SQL. Goes to web service.
MDS3 (Grid Services) • Resource layer: Service data (XML). Service type (WSDL). • Collective layer: index, aggregator. • OGSA framework.