DB Writer fixes and compose.yml update

services/db_write/src/db_writer.py

@@ -6,6 +6,7 @@ from sqlalchemy.pool import QueuePool
 
 from src.config import config
 from src.schema import TelemetryReading
+from src.models import Telemetry
 
 
 class DatabaseWriter:
@@ -37,9 +38,9 @@ class DatabaseWriter:
 
         session = self.SessionLocal()
         try:
-            # Convert to database objects using the correct field mapping
+            # Convert dataclass readings to SQLAlchemy Telemetry objects
             db_objects = [
-                TelemetryReading(
+                Telemetry(
                     time=reading.time,
                     device_id=reading.device_id,
                     metric=reading.metric,
@@ -57,7 +58,7 @@ class DatabaseWriter:
             return True
 
         except Exception as e:
-            self.logger.error(f"Failed to write batch: {e}")
+            self.logger.error(f"Failed to write batch: {e}", exc_info=True)
             session.rollback()
             return False
         finally:

services/db_write/src/models.py

@@ -0,0 +1,30 @@
+"""
+SQLAlchemy models for db_write service.
+
+These models mirror the schema in db_migrations/models.py.
+Keep them in sync when schema changes occur.
+"""
+
+from sqlalchemy import Column, Float, Text, DateTime
+from sqlalchemy.ext.declarative import declarative_base
+
+Base = declarative_base()
+
+
+class Telemetry(Base):
+    """
+    Time-series telemetry data from devices.
+    
+    This model is used by the db_write service to insert data.
+    """
+
+    __tablename__ = "telemetry"
+
+    time = Column(DateTime(timezone=True), primary_key=True, nullable=False)
+    device_id = Column(Text, primary_key=True, nullable=False)
+    metric = Column(Text, primary_key=True, nullable=False)
+    value = Column(Float, nullable=False)
+    unit = Column(Text)
+
+    def __repr__(self):
+        return f"<Telemetry(device={self.device_id}, metric={self.metric}, value={self.value})>"