Types of events in the lifecycle of repository objects, drawn from the PREMIS Event Type vocabulary and augmented with some other event types identified by UCSD. Some of these events correspond to actions performed by the Fedora 4 REST API, while others correspond to actions performed with other systems outside of the repository. Many of the external events (e.g., compression, decompression, decryption, migration, normalization, etc.) might be followed by an internal event (content modification, metadata modification) that saves the output of the process in the repository.
|Event Type||Vocabulary||Internal/ External||Description|
|capture||PREMIS||external||The process whereby a repository actively obtains an object.|
|compression||PREMIS||external||The process of coding data to save storage space or transmission time.|
|creation||PREMIS||internal||The act of creating a new object.|
|deaccession||PREMIS||external||The process of removing an object from the inventory of a repository.|
|decompression||PREMIS||external||The process of reversing the effects of compression.|
|decryption||PREMIS||external||The process of converting encrypted data to plain text.|
|deletion||PREMIS||internal||The process of removing an object from repository storage.|
|digital signature validation||PREMIS||external||The process of determining that a decrypted digital signature matches an expected value.|
|fixity check||PREMIS||both||The process of verifying that an object has not been changed in a given period.|
|ingestion||PREMIS||internal||The process of adding objects to a preservation repository.|
|message digest calculation||PREMIS||external||The process by which a message digest ("hash") is created|
|migration||PREMIS||external||A transformation of an object creating a version in a more contemporary format.|
|normalization||PREMIS||external||A transformation of an object creating a version more conducive to preservation.|
|replication||PREMIS||external||The process of creating a copy of an object that is, bit-wise, identical to the original.|
|validation||PREMIS||external||The process of comparing an object with a standard and noting compliance or exceptions.|
|virus check||PREMIS||external||The process of scanning a file for malicious programs.|
|metadata modification||UCSD||internal||Modifying an RDF source by posting RDF, using SPARQL Update, etc.|
|content modification||UCSD||internal||Modifying a non-RDF source by uploading updated content.|
|content removal||UCSD||internal||Removing a non-RDF source from the repository.|
We are proposing four event types not in PREMIS, and also a distinction between internal and external events. The event types are defined as skos:Concept instances in the PREMIS eventType scheme following the requirements of the PREMIS ontology. Below are the URIs and types for these new concepts:
Description of the kinds of agents that could be recorded for audit events.
- The user operating the software, such as the user uploading a file to the repository.
- When the user is acting on behalf of someone else, the person who directed the action, such as the original contributor of a proxy-deposited item.
- The organization responsible for providing a service, such as running another repository that content is replicated to.
- The systems used to perform an action, such as processing machines for generating derivatives or verifying checksums.
- The software interacting with Fedora 4.
- Other tool(s) used in the process, such as the virus scanning software used to perform a virus check.