We're proud to announce the first Alpha release of Fedora 4. In addition to carrying forward the best qualities of the Fedora platform, Fedora 4 Alpha 1 addresses a number of high priority requirements expressed by the international repository community, including:
- increased performance, with enhanced vertical and horizontal scalability,
- improved durability and service availability,
- built-in support for participating in the world of linked open data,
- easier installation and deployment, and
- an improved platform for developers—one that is easier to work with and will engage a larger corps of developers.
As an alpha release, Fedora 4.0 Alpha 1 is not feature complete. As the final release nears, we'll have full documentation and tooling for migrating existing Fedora 3 repositories, but at this time, we invite you to take this early release of Fedora 4 for a spin, validate our new ideas, contribute your own and join the effort. Developers from the Hydra and Islandora projects have already updated forks of their respective projects to work against Fedora 4's new APIs and now we're ready for the greater Fedora community to do the same.
New Features and Improvements
Durability
- Self-healing
When configured with redundant stores, Fedora supports detection and self-healing of corrupted files. - Transactions
The Fedora APIs now support transactions, with full commit and rollback support. - Clustering for high availability
Fedora now supports clustering multiple Fedora nodes to maximize redundancy and failover. - Metrics and reporting
Built-in metrics and health-checks provide near real-time reporting of repository performance and statistics.
Performance
- Batch operations
The Fedora API now supports batching of methods for increased read and write performance. - Clustering for scalability
Flexible cluster configurations to scale horizontally for read and write performance. - Projection, aka "instant ingest"
Fedora now supports "projecting" over external data sources (such as a filesystem) yet having those resources appear as part of the repository with full support for reading and writing to those external resources.
Flexibility
- HATEOAS support
Fedora 4 now provides a RESTful, hypermedia-driven API that speaks RDF - CMIS
Experimental support for Content Management Interoperability Services - WebDAV
Experimental support for Web Distributed Authoring and Versioning. Work with repository content directly from your desktop. - Eventing, messaging and web hooks
Fedora 4 provides expanded support for event-driven architectures, not only limited to JMS. - OAuth 2
Experimental support for the OAuth 2.0 authorization standard, to support a wider range of authentication and authorization systems via delegation. - Policy-driven storage
Experimental support for authoring policies that direct the storage of a resource based on object or datastream metadata. - More storage options
In addition to filesystem persistence, Fedora 4 now supports higher performance, transactional stores including LevelDB, Berkeley DB and NoSQL stores such as MongoDB.