ATLAS-5312: Add delete propagation support via propagateDelete flag o…

[bhor-sanket]

…n relationship endDefs

What changes were proposed in this pull request?

Background :

Entity relationship model relevant to this change:

hive_db ──(COMPOSITION)──► hive_table ──(COMPOSITION)──► hive_column                                                                                                                                     
                                │                                                                                                                                                                        
                                │ trino_table_hive_table (ASSOCIATION — cross-system alias)                                                                                                              
                                ▼                                                                                                                                                                        
trino_schema ──(AGGREGATION)──► trino_table ──(COMPOSITION)──► trino_column                                                                                                                              
       via trino_table_schema  

Event flow — Trino CLI:

• When a Trino user executes DROP SCHEMA sales CASCADE, the Trino hook sends a single ENTITY_DELETE_V2 notification to Atlas for the trino_schema entity (e.g., qualifiedName=hive.sales@inst1). Trino has already dropped the schema and all tables/columns under it in its catalog — the hook only reports the root entity deletion.

Event flow — Hive client:

• When a Hive user executes DROP DATABASE sales CASCADE, Hive internally drops the database and all tables/columns under it. The Hive Atlas hook then sends multiple ENTITY_DELETE_V2 notifications — one for each entity deleted: hive_db and every hive_table under it . Atlas receives and processes each of these delete events individually.
• However, for each deleted hive_table, any trino_table entities linked to it via the trino_table_hive_table ASSOCIATION relationship remain untouched — because the Hive hook has no knowledge of Trino entities and sends no delete event for them. These trino_table entities (and their trino_column children) become stale metadata representing assets that no longer exist in either Hive or Trino.

Problem Statement :

Problem 1 — Orphaned entities from AGGREGATION relationships (Trino schema drop):
When Trino executes DROP SCHEMA sales CASCADE, Atlas receives ENTITY_DELETE_V2 for trino_schema. Atlas deletes the schema entity but because trino_table_schema is an AGGREGATION relationship (not COMPOSITION), the trino_table entities under that schema are NOT deleted. These tables — and their trino_column children — remain as orphaned stale metadata visible in Atlas UI. The metadata no longer reflects reality in the source system.

Problem 2 — Stale cross-system aliases (Hive database/table drop):

When Hive executes DROP DATABASE sales CASCADE, Atlas correctly cascades deletes through COMPOSITION: hive_db → hive_table → hive_column. However, the trino_table entities that are aliases of those hive_tables (linked via trino_table_hive_table ASSOCIATION relationship) remain intact. These Trino entities represent the same logical asset as the deleted Hive table — they cannot meaningfully exist without their Hive source — yet Atlas leaves them as stale metadata because no Delete mechanism exists for ASSOCIATION relationships.

Combined scenario — full orphan chain:
Deleting hive_db → hive_table is deleted (COMPOSITION) → linked trino_table is NOT deleted (ASSOCIATION) → trino_column under that trino_table is also NOT deleted. Result: stale Trino metadata at multiple levels, all pointing to non-existent Hive entities.

How the patch resolves it :

• Introduces a propagateDelete boolean flag on AtlasRelationshipEndDef (mirroring the existing propagateRename pattern). When an entity is deleted and its type's relationship endDef has propagateDelete=true, the delete cascades to related entities through the configured relationship edges. The flag is resolved at typedef-time into pre-computed deletePropagationTargets on AtlasEntityType, making runtime lookup efficient.
• The typedef configuration IS the cascade signal — no hook-side changes required. Hooks continue sending standard ENTITY_DELETE_V2 events. The model definition declares which relationships should propagate deletes (e.g., trino_table_schema.endDef2.propagateDelete=true means "when a trino_schema is deleted, propagate to trino_table").

How was this patch tested?

Setup :

• Configured Trino hook with Atlas running on Docker
• Applied the patch changes on the Atlas setup

use-cases validation :

Delete Propagation Validation

1. Drop Trino schema with CASCADE (DROP SCHEMA sales CASCADE from Trino CLI)
   - Verified that trino_schema entity is deleted
   - Verified that all trino_table entities under that schema are deleted via propagation
   - Verified that all trino_column entities under those tables are deleted (recursive cascade)
2. Drop Hive table from Hive client (DROP TABLE default.orders)
   - Verified that hive_table entity is deleted
   - Verified that linked trino_table (alias via trino_table_hive_table) is deleted via cross-system propagation
   - Verified that trino_column entities under that trino_table are also deleted
3. Drop Hive database with CASCADE from Hive client (DROP DATABASE sales CASCADE)
   - Verified that hive_db and all hive_table entities are deleted (reported by Hive hook)
   - Verified that linked trino_schema (alias via trino_schema_hive_db) is deleted via propagation
   - Verified that trino_table entities under that trino_schema are deleted via propagation
   - Verified that trino_column entities under those tables are also deleted
4. Idempotent delete — entity already in DELETED state
   - Verified no error when propagation encounters an already-deleted target vertex

Regression Testing

• Create Trino schema and tables
  • Verified creation of Trino schema, table, and Hive entities along with their relationships in Atlas
• Drop Trino table (without schema cascade)
  • Verified deletion of only the trino_table and its columns; schema remains intact
• Rename propagation still works
  • Verified that propagateRename functionality is unaffected after handler rename to Jump to bottom (ctrl+End) ↓ ationPropagationPatchHandler