As development work has continued on PDS, the number of prototype PORTAL registries and the number of records in those registries has grown. More importantly, interest in PDS has grown such that I have received requests to alter the priorities in the development roadmap. The original roadmap as published on the web page PDS Design and later revised in the article A Distributed Infrastructure for Metadata about Metadata: The HDMM Architectural Style and PORTAL-DOORS System called for completing most of the planned functionality on both lexical PORTAL and semantic DOORS services for PDS at a single site before shifting development to multi-site interaction and exchange of records between independent sites. However, in order to enable other PDS server administrators to begin building their own sites sooner rather than later, the development roadmap priorities must be shifted to enable at least the exchange of records for PDS components between different sites.
So what are PDS components? Resource entity types in PDS can be assigned to one of three major groups: component, constituent, and other types. Components include all of the entity types for resources that form the PDS server network including the PDS roots, NEXUS registrars, PORTAL registries and DOORS directories. Constituents include all of the entity types for resources that represent users of the PDS network including persons and organizations. And other refers to all the remaining resource entity types listed on the web page PDS Entities. Note that this list of entity types has been purposefully limited to be as short and general (in an upper-level ontology sense) as possible. But also note that it does include publications, data, computing tools and computing services as well as the entity types Untyped and MetaResourceEntity.
To begin development work on services for the exchange of component records between different PDS sites, there must be some independent sites with which to begin testing implementations. In support of this task, the resource metadata records that have been managed exclusively by GTG Registrar as the sole registrar to date have now been partitioned into three groups and re-assigned to three different registrars as follows:
- PDP Registrar for all PDS component records;
- BHA Registrar for PDS constituent and other resource records in the BrainWatch, Eywa, Gaia and HELPME Registries;
- GTG Registrar for PDS constituent and other resource records in the Beacon, CTGaming, GeneScene, ManRay and Osler Registries.
An updated and more detailed roadmap with the new development plans will appear in a future blog post.