Speaker
Overview
Information provided by EMI Data Products concerning the state of
handled Storage Areas is published through a group of dedicated components, basically called Info Providers. The Info Providers collect and publish status information on Information Service,currently implemented by BDII using LDAP server. The published information adheres to standard GLUE schemas. At the moment the versions 1.3 and 2.0 of GLUE schema exist. Up to EMI starts, the Information Service was exclusively based on the version 1.3 of GLUE schema, and therefore all the Info Providers were publishing status information accordingly. One task of EMI project is to migrate seamlessly to the new-updated version of GLUE schema, and consequently to demand
the use of both versions of GLUE schema for all the EMI Data implementations. We have taken this opportunity to report on the implementation of support for the Glue 2.0 information model in the EMI Data Area.
Impact
The GLUE 2.0 schema was designed to allow a more accurate and natural
description of the resources available on grid infrastructures. By
supporting this, EMI Data is promoting the optimal use of grid resources.
Conclusions
The EMI data group has reached an agreement on the interpretation of
the GLUE 2.0 schema. StoRM, dCache, and DMP publish storage information according to the new schema. The development of this feature has also enabled an internal
refactoring as in the case of StoRM. EMI has committed to the
implementation of GLUE 2.0 support across the relevant services and
clients.
Description of the work
EMI Data has committed to the implementation of GLUE 2.0 support
across the relevant services and clients. This has involved reaching
agreement on a common EMI interpretation of the schema to ensure a
consistent implementation across components. In the case of StoRM, for
example, this also has demanded a review of how the information was
collected and punlished by Info Providers; and the development of a
new interface by an API through which it might have been retrieved all
the information necessary to give a representation of the status of
each Storage Area managed by StoRM. On the one hand this allows StoRM
to greatly simplify the development of info provider and on the other
hand to change the implementation without modifying the external
functional behaviour.
We describe the various tasks required to realise the GLUE 2.0 support
and describe the status of the work. In addition, detail is given on
validation, testing and rollout as well as plans to further exploit
the potential of the new schema.
