feat: separate flow service from config service with explicit queue
lifecycle management
The flow service is now an independent service that owns the lifecycle
of flow and blueprint queues. System services own their own queues.
Consumers never create queues.
Flow service separation:
- New service at trustgraph-flow/trustgraph/flow/service/
- Uses async ConfigClient (RequestResponse pattern) to talk to config
service
- Config service stripped of all flow handling
Queue lifecycle management:
- PubSubBackend protocol gains create_queue, delete_queue,
queue_exists, ensure_queue — all async
- RabbitMQ: implements via pika with asyncio.to_thread internally
- Pulsar: stubs for future admin REST API implementation
- Consumer _connect() no longer creates queues (passive=True for named
queues)
- System services call ensure_queue on startup
- Flow service creates queues on flow start, deletes on flow stop
- Flow service ensures queues for pre-existing flows on startup
Two-phase flow stop:
- Phase 1: set flow status to "stopping", delete processor config
entries
- Phase 2: retry queue deletion, then delete flow record
Config restructure:
- active-flow config replaced with processor:{name} types
- Each processor has its own config type, each flow variant is a key
- Flow start/stop use batch put/delete — single config push per
operation
- FlowProcessor subscribes to its own type only
Blueprint format:
- Processor entries split into topics and parameters dicts
- Flow interfaces use {"flow": "topic"} instead of bare strings
- Specs (ConsumerSpec, ProducerSpec, etc.) read from
definition["topics"]
Tests updated
The metadata field (list of triples) in the pipeline Metadata class
was redundant. Document metadata triples already flow directly from
librarian to triple-store via emit_document_provenance() - they don't
need to pass through the extraction pipeline.
Additionally, chunker and PDF decoder were overwriting metadata to []
anyway, so any metadata passed through the pipeline was being
discarded.
Changes:
- Remove metadata field from Metadata dataclass
(schema/core/metadata.py)
- Update all Metadata instantiations to remove metadata=[]
parameter
- Remove metadata handling from translators (document_loading,
knowledge)
- Remove metadata consumption from extractors (ontology, agent)
- Update gateway serializers and import handlers
- Update all unit, integration, and contract tests
* Changed schema for Value -> Term, majorly breaking change
* Following the schema change, Value -> Term into all processing
* Updated Cassandra for g, p, s, o index patterns (7 indexes)
* Reviewed and updated all tests
* Neo4j, Memgraph and FalkorDB remain broken, will look at once settled down
