Fedora 2019 Architectural Diagrams

Goals

1. Preservation storage
2. Simplicity
3. Performance

Implementation Plan

1. Remove Modeshape (done)
2. Create 2-3 APIs to allow plugging in new backends
3. Implement OCFL 

Major CRUD-Related Interfaces

Persistent vs Derived Application State

This diagram highlights the logical division of persistent content as well a derived state that persists across instance restarts.

Use Case -  Horizontally-Scaled Fedora Instances Running against a single OCFL

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• Name: horizontally scaled fedora

 

OCFL Client with persistent database as authoritative metadata source

WIP:  Fedora Session to OCFL Session Management - try to understand how Fedora Transactions (managed by FedoraSession) would map to a set of OCFL Sessions.

The problem:  A Fedora transaction may span multiple HTTP Requests.   Assuming that we do not want to commit anything to OCFL until the Fedora Transaction is committed, how do we maintain the state of open OCFL Sessions

across requests.  How also do we ensure that two requests using the same transaction ID do not stomp on each other?   It seems that this is only becomes a problem if we want to support autoscaling of Fedora instances.

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• Name: Fedora to OCFL Session Mapping

Use Case:  Simple OCFL - based implementation