- Add comments explaining unique key composition:
- CDC events: (source_topic, offset) = Kafka topic + message offset
- Outbox events: (source_service, event_id) = service name + outbox ID
- Fix contribution-service migration:
- Extend source_service column from VARCHAR(50) to VARCHAR(100)
- Set source_service as NOT NULL to match schema
- Use snake_case for index name consistency
- Clarify that offset/event_id are NOT database auto-increment IDs
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Implements 100% exactly-once semantics for CDC events from 1.0 databases
(identity-service, planting-service, referral-service) to contribution-service.
Key changes:
- Add ProcessedCdcEvent model with (sourceTopic, offset) unique constraint
- Add withIdempotency() wrapper using Serializable transaction isolation
- Add registerTransactionalHandler() for handlers requiring idempotency
- Modify CDC handlers to accept external transaction client
- All database operations now use the passed transaction client
This ensures that:
1. Each CDC event is processed exactly once
2. Idempotency record and business logic are in the same transaction
3. Any failure causes complete rollback
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
hailin