Introducing Fedora 4. Overview, examples, and features. David Wilcox,

Transcription

1 Introducing Fedora 4 Overview, examples, and features David Wilcox,

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3 Learning Outcomes Understand the purpose of a Fedora repository Learn what Fedora can do for you Understand the key capabilities of the software

4 Fedora Facts Managed by DuraSpace (not-for-profit) Funded by the community Collaboratively developed by the community Supported by 2 full-time staff members (not developers)

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6 Flexible Extensible Durable Object Repository Architecture Concept Implementation Community

7 Fedora... Stores, preserves, and provides access to digital objects Supports flexible and complex content models for objects Supports complex semantic relationships between objects inside and outside the repository using RDF Supports millions of objects, both large and small Interoperates with other applications and services

8 Why use Fedora? Fedora is flexible: it can handle both simple and complex use cases Content in Fedora is durable: Fedora supports long-term preservation Fedora powers successful digital repository and DAM applications Fedora is standards-based Fedora is backed by a thriving community

9 Fedora Front-Ends Fedora is middleware You can build a custom framework, or join a broader community:

10 Fedora Examples

11 Institutional Repository

12 Research Data

13 Manuscripts

14 Archives and Special Collections

15 Basic Concepts

16 Web Resources Everything is a web resource with a URI Resources have properties expressed as RDF triples Resources can contain other resources (containers) or files (binaries)

17 Page1.jpg Book Example Page 1 Page1.tiff Container Page2.jpg Book 1 Page 2 Page2.tiff Book Collection Page1.jpg Book 2 Page 1 Page1.tiff Page2.jpg Page 2 Page2.tiff Binary

18 RDF Properties

19 Core Features

20 Fedora as an Implementation (up to 4.6.x)

21 Fedora as an Implementation (4.7+)

22 Fedora as an API Aligning with standards Focal point for community discussion and consensus on what a Fedora repository does Enables standard client libraries Enables standard server components

23 Standards Focus on existing standards Fewer customizations to maintain Opportunities to participate in related communities

24 Core Features and Standards 1. Create/Read/Update/Delete - Linked Data Platform 2. Versioning - Memento 3. Authorization - WebAC 4. Batch Operations 5. Fixity

25 Versioning Versions can be created on demand via the REST-API A previous version can be restored via the REST-API

26 Authorization Authorization is optional and pluggable Currently, four authorization implementations exist: None, WebAC, Role-based and XACML

27 Web Access Control W3C approach for managing authorization using linked data Interoperable with other applications that implement the same approach Implemented in Fedora 4 by community stakeholders

28 Batch Operations Multiple actions can be bundled together into a single repository event Batch operations can be rolled back or committed Can be used to maintain consistency

29 Fixity Over time, digital objects can become corrupt Fixity checks help preserve digital objects by verifying their integrity On ingest, Fedora can verify a user-provided checksum against the calculated value A checksum can be recalculated and compared at any time via a REST-API request

30 Messaging* Fedora emits JMS messages on repository events Message body is RDF, serialized to JSON-LD (default) Messaging allows external integrations to react asynchronously to events

31 External Services

32 Two Feature Types 1) Optional, pluggable components Separate projects that can interact with Fedora 4 using a common pattern 2) External components Consume and act off repository messages

33 External Component Integrations Leverages the well-supported Apache Camel project Camel is middleware for integration with external systems Can handle any asynchronous, event-driven workflow

34 External Component Architecture Fedora 4 Apache Camel LDP / WebAC / Memento Solr Triplestore (Fuseki, Sesame) Audit Service SPARQL-Query

35 External - Indexing Index repository content for search Indexing is configurable - could be based on any property Solr and Elastic Search have been tested

36 External - Triplestore An external triplestore can be used to index the RDF triples of Fedora resources Any triplestore that supports SPARQL-update can be plugged in Fuseki, RDF4J, and BlazeGraph have been tested

37 External/Pluggable - Audit Service Maintains a history of events for each repository resource Both internal repository events and events from external sources can be recorded Uses the existing event system and an external triplestore Events can be persisted back to Fedora

38 Performance and Scalability

39 Test Plans Testing large files, many files, and many containers Tests are performed by community members Have concerns about performance and scale? Join the group!

40 Metrics A number of scalability tests have been run: Uploaded a 1 TB file via REST API 17 million objects via REST API 3.5 million files via REST API

41 Roadmap

42 Support standardized import/export Specify RESTful API Defining Fedora by its RESTful services Aligning those services with standards Specifying RESTful services Creating technology compatibility kit (TCK) Separating service specification from server-side implementation

43 Useful Resources Fedora 4 documentation Fedora 4 wiki Fedora 4 mailing lists