Status Propagation Rules

The PTT system implements automatic status propagation between related entities following a hierarchical relationship: Project → SBD → SBI → EB.

Entity Relationships

The system maintains the following entity hierarchy:

  • Project: Contains multiple SBDs (one-to-many)

  • SBD (Scheduling Block Definition): Contains multiple SBIs (one-to-many)

  • SBI (Scheduling Block Instance): Contains multiple EBs (one-to-many)

  • EB (Execution Block): Leaf entity in the hierarchy

Top-Down Propagation

Status changes propagate from parent to child entities:

Project Status Changes

Project → “Ready”

  • All associated SBDs transition to “Ready” state

  • Ensures all scheduling blocks are prepared when project is approved

Project → “Cancelled”

  • Associated SBDs move to “Suspended” state

  • Associated SBIs move to “Failed” state

  • Associated EBs move to “Failed” state

  • Cascades cancellation through entire project hierarchy

Bottom-Up Propagation

Status changes propagate from child to parent entities:

EB Status Changes

EB → “Fully Observed”

  • Associated SBI transitions to “Observed”

  • Linked SBD transitions to “Observed”

  • Project transitions to “Observed”

  • Indicates successful completion of observation

EB → “Failed”

  • Associated SBI transitions to “Failed”

  • Linked SBD transitions to “Suspended”

  • Project transitions to “Cancelled”

  • Propagates failure up the hierarchy

SBI Status Changes

SBI → “Executing”

  • Associated SBD transitions to “In Progress”

  • Project transitions to “Ready”

  • Indicates active observation execution

Implementation Notes

  • Status propagation is automatic and immediate

  • Changes are logged in the status history

  • The system maintains referential integrity during propagation

  • All status transitions are auditable through the status history API

Technical Implementation

The status propagation system is implemented using PostgreSQL’s Ltree extension for efficient hierarchical data management. This approach provides:

  • Hierarchical Path Representation: Each entity maintains a path showing its position in the hierarchy

  • Efficient Tree Operations: Fast ancestor/descendant queries using Ltree operators

  • Scalable Performance: Optimized for large hierarchical datasets

  • ACID Compliance: Ensures data consistency during propagation

For detailed technical implementation, see the Status Toy Documentation which demonstrates the Ltree-based approach used in this system.

API Endpoints

Status propagation can be monitored through:

  • GET /entity/latest/status - View current entity statuses

  • GET /entity/current/status - View current status view

  • PUT /entity/{entity_id}/status - Update entity status

  • GET /entity/history - View status change history

  • GET /entity/status/get_entity - Get entity status dictionary

  • GET /status/stream - Real-time status change notifications