1. April 4, 2002Atlas Testbed Workshop ATLAS Hierarchical MDS Server Patrick McGuigan

2. April 4, 2002Atlas Testbed Workshop Introduction Current state of information gathering –Information can be: Node existence/configuration Installed software Services –Methods Gridview Mailing lists / teleconferences grid-info-search on known hosts How do we evolve a strategy for the entire testbed?

3. April 4, 2002Atlas Testbed Workshop Hierarchical GIIS for ATLAS Moves testbed toward being a Virtual Organization (VO) Provides mechanism for distributed information retrieval by querying well known resources Allows users or agents to compare information about distributed resources.

4. April 4, 2002Atlas Testbed Workshop Background GRIS GIIS IP GIIS is queried GIIS suffers cache miss; GRIS is queried GRIS suffers cache miss; Information Provider launched IP returns entry to GRIS GRIS fills cache; returns entry to GIIS GIIS fills cache; returns entry to caller Soft-state registration

5. April 4, 2002Atlas Testbed Workshop Background GRIS GIIS 1 IP GIIS 2 GRIS registers with GIIS 1 GRIS is registrant GIIS 1 is registrar GIIS 1 registers with GIIS 2 GIIS 1 is registrant GIIS 2 is registrar Registration is an LDAP entry that has a specified time to live (TTL)

6. April 4, 2002Atlas Testbed Workshop Background (cont.) GRIS GIIS 1 IP GIIS 2 GIIS 3 GIIS 4 An entity can register with multiple “parents”

7. April 4, 2002Atlas Testbed Workshop Testbed GIIS Hierarchy BNLBUIndianaANLLBLUMichOUUTA ATLAS_TB Primary GIIS at UTA Alternate GIIS at ? Site level GIIS’s

8. April 4, 2002Atlas Testbed Workshop Testbed Site Policy Issues Each testbed site registers one or more site- level GIIS The name of a site-level GIIS should be based on domain name Testbed sites are free to develop internal structure

9. April 4, 2002Atlas Testbed Workshop Reliability Concerns Dual registrations guard against single point of failure Secondary GIIS is not a replica Secondary and Primary GIIS’s may have different values for an entry during the entry’s TTL Dual registrations a problem if Atlas GIIS reports to a parent

10. April 4, 2002Atlas Testbed Workshop Security Issues Security is not mature in GIIS backend – Performs anonymous binds to registrants when suffering a cache miss –Ignores binding rules when accepting registration messages For now –Allow anonymous binds –Use filtering rule for accepting specific registrations

11. April 4, 2002Atlas Testbed Workshop LDAP Configuration Schema files control structure of entries in LDAP Schema elements are required to be globally unique. Becomes an issue if testbed members are interested in developing information providers and schema elements A registrar should have the same schema files as all registrants.

12. April 4, 2002Atlas Testbed Workshop Implementation Instructions http://www-hep.uta.edu/~mcguigan/atlas_giis