- turned model_variables into a class with lazy loading

- some improvements to Healthchecks

common/models/monitoring.py

@@ -0,0 +1,28 @@
+from common.extensions import db
+from sqlalchemy.dialects.postgresql import JSONB
+import sqlalchemy as sa
+
+
+class LLMUsageMetric(db.Model):
+    __bind_key__ = 'public'
+    __table_args__ = {'schema': 'public'}
+
+    id = db.Column(db.Integer, primary_key=True)
+    tenant_id = db.Column(db.Integer, nullable=False)
+    environment = db.Column(db.String(20), nullable=False)
+    activity = db.Column(db.String(20), nullable=False)
+    sub_activity = db.Column(db.String(20), nullable=False)
+    activity_detail = db.Column(db.String(50), nullable=True)
+    session_id = db.Column(db.String(50), nullable=True)        # Chat Session ID
+    interaction_id = db.Column(db.Integer, nullable=True)       # Chat Interaction ID
+    document_version_id = db.Column(db.Integer, nullable=True)
+    prompt_tokens = db.Column(db.Integer, nullable=True)
+    completion_tokens = db.Column(db.Integer, nullable=True)
+    total_tokens = db.Column(db.Integer, nullable=True)
+    cost = db.Column(db.Float, nullable=True)
+    latency = db.Column(db.Float, nullable=True)
+    model_name = db.Column(db.String(50), nullable=False)
+    timestamp = db.Column(db.DateTime, nullable=False)
+    additional_info = db.Column(JSONB, nullable=True)
+
+    # Add any additional fields or methods as needed