Use Case 05 - Update Science Metadata

Revisions

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Goal

Update or delete science metadata record on a Member Node.

Summary

Science metadata is immutable in DataONE. As such, modification involves generating a new science metadata record and indicating that the new record supersedes an existing record, and deletion involves deprecation so that the old metadata record is no longer visible during normal discovery and access.

Figure 1. Sketch of interactions involved in updating a science metadata object. An authenticated user calls the MN_crud.update() operation on a Member Node (A) with a new science metadata document and the identifier of the document being replaced. The update method sets the SystemMetadata.obsoletedBy property of the original document system metadata with the identifier of the new science metadata document (B), and the SystemMetadata.obsoletes property of the system metadata associated with the new science metadata is set to the identifier of the science metadata document being replaced (C). The Coordinating Nodes pick up the changes on the next Member Node synchronization (D). Changes are subsequently propagated to the replica locations.

Actors

Member Node, additional Member Nodes, Coordinating Nodes

Preconditions

• User is authenticated
• MN is registered and is monitored
• Science metadata being deleted / updated document exists

Triggers

• User calls MN_crud.update()
• User calls MN_crud.delete()

Post Conditions

• System metadata for science metadata object(s) updated
• Replacement science metadata propagated through the system
• Search indexes updated
• Operation recorded in logs
• Watchers notified of change

Figure 2. Use case 04.

Figure 3. Create, update, delete, search metadata or data object in Member Node.

Notes

• Q. Are IDs are pegged to versions? If so, update might differ more radically from create. A. Yes. Create involves creation of a new science metadata object, update involves deprecating an existing science metadata document with a replacement, delete involves setting system metadata properties.
• Q. Should queuing of a submission within a member node be required for success? (We assume yes, to guarantee replication of submissions). A. No. Successful update is handled by the Member Node, if the new science metadata can be created and the system metadata can be updated, then the change should be considered complete. The Member Node synchronization process will ensure that the changes are propagated to the wider system.