The aDORe Federation Architecture

TL;DR

The paper presents the aDORe federation architecture, a scalable framework for federating digital repositories to address scalability and unified access needs, demonstrated through large-scale deployments at Los Alamos and Ghent University.

Contribution

It introduces a high-level 3-tier architecture for repository federation, providing core interfaces and infrastructure components for scalable, unified digital repository access.

Findings

Successful deployment in large-scale repositories

Supports federating over 100 million objects

Enables unified access across distributed repositories

Abstract

The need to federate repositories emerges in two distinctive scenarios. In one scenario, scalability-related problems in the operation of a repository reach a point beyond which continued service requires parallelization and hence federation of the repository infrastructure. In the other scenario, multiple distributed repositories manage collections of interest to certain communities or applications, and federation is an approach to present a unified perspective across these repositories. The high-level, 3-Tier aDORe federation architecture can be used as a guideline to federate repositories in both cases. This paper describes the architecture, consisting of core interfaces for federated repositories in Tier-1, two shared infrastructure components in Tier-2, and a single-point of access to the federation in Tier-3. The paper also illustrates two large-scale deployments of the aDORe federation architecture: the aDORe Archive repository (over 100,000,000 digital objects) at the Los Alamos National Laboratory and the Ghent University Image Repository federation (multiple terabytes of image files).