Release date: 12 October, 2015
We are proud to announce the release of Fedora 4.4.0.
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Summary
The Fedora 4.4.0 release furthers several major objectives:
- Tighten the definition the RESTful application programming interface (API)
- Further align this API to community standards, including the Linked Data Platform (LDP) and Web Access Control (WebAC)
- Improve tooling for legacy Fedora repositories to Fedora4
- Improve tooling for external services live in the ecosystem around the repository
- Fix bugs
This release is a major release (i.e. 4.4.0 instead of 4.3.1) because there are a two updates that are not strictly speaking backwards compatible with 4.3.0:
- HTTP GET requests on descriptions of NonRDF resources (i.e. binaries) now return RDF triples that all have the NonRDF resource as the subject, whereas previously the returned RDF contained a mix of subjects in the response: some subjects were the NonRDF resource, some subjects were the NonRDF description resource
- When requesting the fixity service be performed on a binary resource, the "status" of the fixity result has been changed in this release from: "fedora:status" to "premis:hasEventOutcome"
Although not a backwards incompatible update in the 4.4.0 release, it should be noted that the Import and Export services [] have been deprecated due to their reliance on a JCR serialization versus an RDF-centric approach. These services will be supplanted by externalized machinery that transacts in RDF.
Updates
Community Registry
To minimize the barriers to using Fedora, a free, opensource application, there is no required "registration" process. However, it is extremely beneficial to the broader Fedora community if we collectively aggregate some minimal details describing our respective repository installations.
DuraSpace maintains a registry [] of installations that is populated on a voluntary basis. The 4.4.0 release raises the visibility of that registry, and hopefully the likelihood that repository managers will self-register in it, by adding a link on the Fedora installation spash-page requesting exactly that.
Application Programming Interface
One of the technical priorities [] of Fedora is to define a well-specified application programming interface (API) against which client applications can be written and future server-side implementations can be created. This Fedora API should be clear and detailed enough such that a cooresponding technology compatibility kit (TCK) would be able to indicate if the any Fedora implementation fullfills or diverges from the specification. With this in mind, several issues where addressed in this release that clean up Fedora's RESTful interaction and tease out the non-core aspects of the Fedora ontology [].
Linked Data Platform alignment
Upgrading and Migrating
A primary focus of the ongoing Fedora effort is to facilitate the upgrade/migration of Fedora3 repositories to Fedora4. To those ends, a number of improvements have been incorporated into the "migration-utils [9]" upgration utility.
- Packaging the utility as a standalone executable application
- Using opaque identifiers for migrated resources
- Adding support for user-provided RDF namespace mappings
- Providing specific mappings of Fedora3 to Fedora4 properties
- Improving support for migrating resources with non-existent datastreams
External Services
Web Access Control
Housekeeping and Bugfixes
Numerous refactorings, bugfixes, and clean-up tasks were addressed in this release. Some of the highlights include:
- ...
References
[1] https://wiki.duraspace.org/display/FF/Downloads [2] http://docs.fcrepo.org [3]
