Metacat OAI Provider

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Revision as of 13:33, 26 February 2009 by Ryan Scherle (talk | contribs) (Open Questions)

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UNM is creating an OAI-PMH provider to add on to Metacat. The core Metacat code is available from the Ecoinformatics SVN. This work will integrate directly into the Metacat development tree.

Requirements

  • Our primary goal is to enhance access, not to provide a failover copy. It is ok for Dryad to only store the Dryad-format metadata, and not use the full EML.
  • Metacat exposes all metadata through an OAI-PMH provider.
  • The provider makes all data available in these formats:
  • Dryad harvests all metadata exposed by Metacat.
    • The record in Dryad must point to the record in Metacat, enabling users to find the actual datasets.
  • Metacat harvests metadata from the Dryad OAI-PMH provider, and makes it available alongside the native Metacat metadata.
  • The design of the OAI-PMH "adapter" should provide a more generalized interface that supports cross-walking other metadata standards to/from Metacat beyond just EML.
  • Not an actual requirement, but keep in mind that we need to eventually download the data files.

Tasks

  • Ryan/Mark: schedule a bi-weekly call to touch base on progress.
  • Ryan: discuss with Matt Jones (and Mark?) how to ensure that we're implementing things in a way to will work well for other Metacat installations.
  • Ryan: work with MRC to determine "ideal" Dryad records.
    • Initial versions are done, but Ryan needs to verify.
  • Duane: Create XSL to convert EML -> simple DC. (1 week)
  • Duane: Create XSL to convert EML -> Dryad application profile. (3 weeks)
  • Duane: Create XSL to convert dryad application profile -> EML. (included in above)
  • Ryan: Evaluate quality of simple DC and Dryad application profile records, suggest modifications to XSL.
  • Duane: Complete/create OAI-PMH provider functionality in LTER Metacat. (2 months)
    • Depending on status of current Metacat functionality, either complete existing implementation, or integrate a new system such as OCLC's OAIcat, a UIUC provider, or the DLESE provider.
      • Note: There is no existing OAI-PMH implementation for Metacat (per Matt Jones).
  • Ryan: Configure harvest of Metacat metadata and test metadata availability in Dryad. (1 week)
  • Duane: Install an OAI-PMH harvester at LTER and configure to harvest from the Dryad provider. (1 month)

Open Questions

  • Should any "sets" be defined in the provider? Is there any natural breakdown of the MetaCat data into categories?
    • Identity of data provider (which LTER site)
  • Is there any need to convert from simple DC to EML?
    • This is desirable in the long run, but may not be needed for the immediate project.
  • UNM can send us the metacat XSL, so we can display EML "properly" if we want. Is there any reason Dryad should display the EML in a more Metacat-like manner?

About Metacat

Metacat supports "simple" URLs with the format: http://metacat.lternet.edu/knb/metacat/knb-lter-nin.24402/lter

  • knb-lter-nin.24402 is the ID
  • lter is the presentation format

Metacat supports LSID with the format: urn:lsid:esa.org:esa:8:7

  • LSID resolving is "only local" (not remote metacat servers?)
  • LSID is used as the accession number by ESA, but what do other sites use?

Mailing list is at http://mercury.nceas.ucsb.edu/ecoinformatics/mailman/listinfo/metacat-dev

About EML

The EML schema documents (EML 2.0.1) can be downloaded at http://knb.ecoinformatics.org/software/download.html#eml (note that there is a new revision, EML 2.1, of the schema due to be released this Spring).

EML examples:

station at Brunswick, Georgia for 1915 to 2004.

Data in EML that has no logical place in the Dryad Application Profile:

  • description of dataset size, encoding, table format, implementation details
  • details of fields within the dataset
  • geographic bounding boxes
  • processing method
  • software
  • author/organization distinction
  • access control