The project goals are:
- To define requirements for an interface or dashboard for collection curators to send digital objects from their local Hyrax/Fedora repository to a DDP (specifically Chronopolis, but configurable to other DDPs) with a simple click of the mouse, allowing for updated versions to also be automatically delivered to the DDP service.
- To define the development work needed to integrate the Hyrax/Fedora, DuraCloud Bridge, and Chronopolis systems in order to allow for integrated object versioning and reporting between the systems.
- To define the requirements for the user interface for version information and tracking of data sent to a DDP service within the Hyrax/Fedora interface, as well as information about data replication and audit throughout Chronopolis.
To ensure that the created definitions, specifications and design documents are applicable to other digital repository software and other DDP services. Project personnel will spend significant time working with project partners and advisors at all stages, with the goal that the outcomes created are in sync with other systems and services.
These project goals are designed to provide a model for how local repositories should interact with DDP services. Currently, the entire process of sending local repository data to any existing DDP service is manual. Data residing in the local repository is exported out of the system using the export functionality provided by the repository and then ingested into the DDP network using the tools provided by that network. It is important to note that an institution may not want to send all of the data in their local repository to a DDP service; these services can be expensive, and the institution may decide that not all of their repository data warrants that level of preservation. In these cases, there is no way for the local repository to internally track which materials have been sent to a DDP service.
In addition to identifying the use cases the overall technical architecture will support, one of the first tasks of this project will be to determine a versioning mechanism that is implemented by the local Hyrax/Fedora repository system. This versioning mechanism needs to be able to export relevant versioning information in a way that can be tracked by Chronopolis. Specifically, a versioning mechanism should help insure that new versions of objects and/or object metadata can automatically or manually be sent to Chronopolis and Chronopolis will maintain the versioned relationships in a manner that will make it easier to restore the objects into the local Fedora system. One possible means of accomplishing this versioning process is through the implementation of the Oxford Common File Layout (OCFL) specification. This new specification is a community-led initiative designed to provide a standard mechanism of arranging objects and their versions on the storage filesystem in a manner in which their version relationships are essentially human-understandable. Even though the OCFL specification is fairly new, it is based on the Moab design for object versioning, which has been developed and used by Stanford University for a number of years.10 The Moab design is recognized as one of the few (if not only) systematic approaches designed to address versioning considerations within a digital preservation system. Versioning is a key issue for the work in this proposal, because it is one way to track how requested changes in an access system (i.e. Hyrax) are propagated and tracked in a preservation system (Chronopolis). Because OCFL is based on Moab, it has versioning included within its default set of functions. The OCFL initiative started in late 2017 and the editorial committee is expecting to have an initial specification release by fall 2018. This project will review OCFL as a possible versioning mechanism and incorporate it into the systems design if it provides support for the project’s selected use cases. Two of the project participants serve on the OCFL editorial committee and will be able to provide expertise on the specification.
In addition to increased version interoperability between Hyrax/Fedora and Chronopolis, this project will also outline the specification needed to deliver information about the object once it is distributed into the Chronopolis network. This information includes preservation event data such as date of registration into Chronopolis, date of replication to each Chronopolis node (and node location), and date of last audit.
