Learning Outcomes
- Understand the purpose of a repository
- Learn what Fedora can do for you
- Understand the key capabilities of the software
Course Outline
Introduction to Fedora 4
What is a Repository?
- Secure software that stores, preserves, and provides access to digital materials
- Supports complex semantic relationships between objects both within and outside the repository
- Supports millions of objects, both large and small
- Capable of interoperating with other applications and services
Fedora 4 Guiding Principles
- Improved performance, enhanced vertical and horizontal scalability
- More flexible storage options
- Features to accommodate research data management
- Better capabilities for participating in the world of linked open data
- An improved platform for developers—one that is easier to work with and which will attract a larger core of developers.
Exposing and Connecting Content with Fedora 4
- Flexible, extensible object modelling
- Atomic objects with semantic connections using standard ontologies
- RDF-based metadata using Linked Data
- RESTful API with native RDF response format
Core Components
Durable Storage
Features relating to preservation and long-term access.
Fixity
Generating and comparing checksums.
Backup and Restore
Full repository backup and restoration.
Export and Import
Export a node or a section of the node hierarchy.
Import an exported node or node hierarchy.
Option to export in JCR/XML for transparency.
Versioning
Versions can be created across the entire repository or on particular API calls.
Policy-Driven Storage
Policies can route different types of files to different back-end storage locations on ingest.
Data Modelling
Content Models
Content can be modelled using Compact Node Definitions (CNDs).
A CND can define a number of properties and be assigned to objects as a mixin.
Any number of mixins can be assigned to an object; they are cumulative.
Linked Data
Compliance with LDP 1.0 spec.
Node properties are RDF triples.
Metadata can be represented as RDF triples.
Many possibilities for exposing, importing, sharing resources with other web applications.
User Interface
Administrative Console
Tour of the HTML administrative interface.
Internal Search
Simple property search and limited SPARQL endpoint.
External Components
Indexing
Triplestore
Similar to external search, an external triplestore can be plugged into Fedora 4. The same JMS message consumer relays repository events to the triplestore index (e.g. Fuseki, Sesame).
External Search
Repository events generate JMS messages, which can be consumed by a JMS message consumer and relayed to an external search index (e.g. Solr).
Authorization
Pluggable authorization framework.
Basic Authorization
Role-based authentication.
XACML Authorization
XACML enforcement implementation.
Performance
Transactions
Multiple actions can be bundled together into a single repository event (transaction).
Transactions offer performance benefits by cutting down on the number of times data is written to the repository filesystem (which tends to be the slowest action).
Clustering
