INFN Grid Information Services G. Lo Biondo INFN Milano (presented by F. Prelz)

As far as now… INFN runs a hierarchical GIS distributed among geographical INFN sites.

Bologna (LAN) GIIS dc=bo,dc=infn,dc=it,o=grid GIIS dc=mi,dc=infn,dc=it,o=grid Top Level INFN GIIS dc=infn,dc=it,o=grid Milano( LAN) GRIS Each site runs an Index server that registers itself to a top level INFN GIIS server

Still to do... Although the INFN GIS is up and running, it still lacks some production environment capabilities. –Some deployment issues can be addressed in a simple way. –Other issues are tied to the GIS LDAP based architectural model. They require a deeper analysis and must be faced in a context wider than the INFN-GRID project.

Still to do... Here is a short description of open issues in the current INFN GIS deployment: –Site Independence (Site functionality must not rely on higher lever services) –Service Reliability (Automatic failover mechanisms) –Service Distribution (Topological distribution of the service) –GRIS/GIIS Registration Mechanism.

Site Independence Each INFN site must be able to locate local resources independently of the root GIIS status. Anyway, it's only a matter of using the LDAP native referral mechanism properly.

Bologna (LAN) GIIS dc=bo, dc=infn,dc=it,o=grid GIIS dc=mi,dc=infn,dc=it,o=grid Top Level INFN GIIS ldap://mds.infn.it:389/ dc=infn,dc=it,o=grid Milano( LAN) GIS CLIENT Where is your parent? Try: ldap://mds.infn.it:389/dc=infn,dc=it,o=grid

Service Reliability Replication must be available at all tree levels to reduce service faults. Slapd replication or synchronization engines must be developed/deployed. A mechanism to automatically locate LDAP servers and replicas must be decided (a possibility is to use DNS SRV RRs or other DNS RRs)

Bologna (LAN) GIIS dc=bo, dc=infn,dc=it,o=grid GIIS dc=mi,dc=infn,dc=it,o=grid Top Level INFN GIIS dc=infn,dc=it,o=grid Milano( LAN) GIIS Top Level INFN GIIS Replication/ Synchronization engine Replication/ Synchronization engine

Architectural issues The LDAP based model of the Globus GIS has some advantages: –Standard Protocol and APIs –Standard Data Presentation Model –Existing software On the other hand the LDAP protocol is not the best provider for dynamic data. Though LDAP is a ready to use solution other IS models must be investigated.

Service Distribution The pull model (chaining) used for data publishing, in some circumstances is not the best approach. –On a large distributed GIS, searches affecting the whole resource collection can be dramatically slow. –We may want to push information to superior knowledge servers as the information changes. A mixed push/pull model is more suitable for real applications. A way to narrow searches must be investigated (indexing?)

Registration Mechanism Registrations sent from GRIS’s to a GIIS basically inform about the existence of a resource. Currently, registrations are completely anonymous meaning that everyone can register an host on a GIIS. Access to data is completely anonymous at all tree levels: this exposes “private” data, if any.

GIS Future As the GIS is a new, not well standardized Information Service, it is very important that the standardization process be coordinated both from the deployment and from the protocol specifications perspectives. This assumes a tightened collaboration between Grid projects to define and deploy a common GIS model.