fix: единый singleton engine в bd, убраны 17 локальных make_engine()

- bd/__init__.py: добавлены get_engine() и get_session() — один SQLAlchemy engine на весь процесс
- make_engine(): pool_size=5, max_overflow=5, pool_timeout=30, pool_recycle=1800
- Все 17 route-файлов: убраны локальные get_session()/make_engine(), импорт из bd
- transfer_crud.py: _get_session() → get_session() из bd
- init_data_base.py: get_engine() вместо make_engine()
- Результат: 78 idle соединений → 1

bd/__init__.py

@@ -47,7 +47,11 @@ def make_engine():
         s.DATABASE_URL_syncpg,
         connect_args=s.PG8000_CONNECT_ARGS,
         future=True,
-        pool_pre_ping=True,       # проверяет соединение перед каждым запросом
+        pool_pre_ping=True,
+        pool_size=5,
+        max_overflow=5,
+        pool_timeout=30,
+        pool_recycle=1800,
     )
 
 
@@ -70,3 +74,22 @@ def wait_for_db(retries: int = 15, delay: float = 2.0) -> None:
             if attempt < retries:
                 time.sleep(delay)
     raise RuntimeError("PostgreSQL did not become ready in time.")
+
+# ── Singleton engine + session factory (один движок на весь процесс) ───────
+_engine = None
+_SessionFactory = None
+
+
+def get_engine():
+    global _engine
+    if _engine is None:
+        _engine = make_engine()
+    return _engine
+
+
+def get_session():
+    global _SessionFactory
+    if _SessionFactory is None:
+        from sqlalchemy.orm import sessionmaker
+        _SessionFactory = sessionmaker(bind=get_engine(), future=True)
+    return _SessionFactory

route/auth.py

@@ -5,7 +5,7 @@ from typing import Optional
 from datetime import datetime, timezone
 import uuid
 
-from bd import make_engine
+from bd import get_session
 
 from bd.tables.users import User
 from route.auth_utils import hash_password, verify_password, create_access_token, SECRET_KEY, ALGORITHM, oauth2_scheme
@@ -15,9 +15,6 @@ from redis_db import blacklist_token
 router = APIRouter(tags=["auth"], prefix="/auth")
 
 
-def get_session():
-    from sqlalchemy.orm import sessionmaker
-    return sessionmaker(bind=make_engine(), future=True)
 
 
 class RegisterIn(BaseModel):

route/auth_utils.py

@@ -9,7 +9,7 @@ from fastapi.security import OAuth2PasswordBearer
 from jose import JWTError, jwt
 from passlib.context import CryptContext
 
-from bd import make_engine
+from bd import get_session
 
 SECRET_KEY: str = os.getenv("SECRET_KEY", "")
 if not SECRET_KEY:
@@ -45,9 +45,6 @@ def create_access_token(data: dict, expires_delta: Optional[timedelta] = None) -
     return jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
 
 
-def get_session():
-    from sqlalchemy.orm import sessionmaker
-    return sessionmaker(bind=make_engine(), future=True)
 
 
 def get_current_user(token: str = Depends(oauth2_scheme)):

route/choice_crud.py

@@ -3,7 +3,7 @@ from pydantic import BaseModel
 from typing import Optional
 import uuid
 
-from bd import make_engine
+from bd import get_session
 
 from bd.tables.choice import Choice
 from bd.tables.question import Question
@@ -23,9 +23,6 @@ class ChoiceUpdate(BaseModel):
     position: Optional[int]
 
 
-def get_session():
-    from sqlalchemy.orm import sessionmaker
-    return sessionmaker(bind=make_engine(), future=True)
 
 
 @router.post("/", status_code=201, dependencies=[Depends(require_admin_key)])

route/glomshtok_crud.py

@@ -24,7 +24,7 @@
 from fastapi import APIRouter, HTTPException
 import uuid
 
-from bd import make_engine
+from bd import get_session
 from bd.tables.poll import Poll
 from bd.tables.question import Question
 from bd.tables.choice import Choice
@@ -372,9 +372,6 @@ CHOICE_SCORES: dict[int, float] = {
 CHOICE_LABELS: list[str] = ["++", "+", "0", "-", "--"]
 
 
-def get_session():
-    from sqlalchemy.orm import sessionmaker
-    return sessionmaker(bind=make_engine(), future=True)
 
 
 @router.post("/glomshtok", status_code=201)

route/groups_crud.py

@@ -3,7 +3,7 @@ from pydantic import BaseModel
 from typing import Optional
 import uuid
 
-from bd import make_engine
+from bd import get_session
 
 from bd.tables.group import Group
 from route.auth_utils import require_admin_key
@@ -19,9 +19,6 @@ class GroupUpdate(BaseModel):
     name_group: Optional[str] = None
 
 
-def get_session():
-    from sqlalchemy.orm import sessionmaker
-    return sessionmaker(bind=make_engine(), future=True)
 
 
 def _group_dict(grp: Group) -> dict:

route/holland_crud.py

@@ -2,7 +2,7 @@ from fastapi import APIRouter, HTTPException
 from typing import Optional
 import uuid
 
-from bd import make_engine
+from bd import get_session
 
 from bd.tables.poll import Poll
 from bd.tables.question import Question
@@ -141,9 +141,6 @@ DIMENSIONS = [
 ]
 
 
-def get_session():
-    from sqlalchemy.orm import sessionmaker
-    return sessionmaker(bind=make_engine(), future=True)
 
 
 @router.post("/holland", status_code=201)

route/init_data_base.py

@@ -4,7 +4,7 @@ import importlib
 from pathlib import Path
 from typing import List
 
-from bd import Settings, make_engine
+from bd import Settings, get_engine
 from sqlalchemy import text
 from sqlalchemy.exc import SQLAlchemyError
 from pydantic import BaseModel
@@ -48,7 +48,7 @@ async def create_tables():
 
     Endpoint вызывается по нажатию кнопки в UI (POST).
     """
-    engine = make_engine()
+    engine = get_engine()
 
     metadatas = collect_metadatas()
     if not metadatas:
@@ -73,7 +73,7 @@ async def create_tables():
 @router.post("/db/migrate-cascade-user", dependencies=[Depends(require_admin_key)])
 async def migrate_cascade_user():
     """Добавляет FK responses.user_id → users.id ON DELETE CASCADE, если ещё не существует."""
-    engine = make_engine()
+    engine = get_engine()
     try:
         with engine.connect() as conn:
             conn.execute(text("""
@@ -97,7 +97,7 @@ async def migrate_cascade_user():
 @router.post("/db/migrate-users", dependencies=[Depends(require_admin_key)])
 async def migrate_users():
     """Добавляет колонки username и hashed_password в таблицу users, если они ещё не существуют."""
-    engine = make_engine()
+    engine = get_engine()
     try:
         with engine.connect() as conn:
             conn.execute(text("""
@@ -118,7 +118,7 @@ class ClearDBIn(BaseModel):
 @router.post("/db/migrate", dependencies=[Depends(require_admin_key)])
 async def migrate_tables():
     """Приводит схему БД в соответствие с моделями: убирает устаревшие колонки, добавляет новые."""
-    engine = make_engine()
+    engine = get_engine()
     migrations = [
         # Убираем старый FK и колонку group.user_id (если остался от прежней схемы)
         'ALTER TABLE "group" DROP COLUMN IF EXISTS user_id',
@@ -150,7 +150,7 @@ async def clear_tables(payload: ClearDBIn):
     if not payload.confirm:
         raise HTTPException(status_code=400, detail="Confirmation required")
 
-    engine = make_engine()
+    engine = get_engine()
 
     metadatas = collect_metadatas()
     if not metadatas:

route/klimov_crud.py

@@ -14,7 +14,7 @@ from fastapi import APIRouter, HTTPException
 from typing import Optional
 import uuid
 
-from bd import make_engine
+from bd import get_session
 from bd.tables.poll import Poll
 from bd.tables.question import Question
 from bd.tables.choice import Choice
@@ -159,9 +159,6 @@ DIMENSIONS = [
 ]
 
 
-def get_session():
-    from sqlalchemy.orm import sessionmaker
-    return sessionmaker(bind=make_engine(), future=True)
 
 
 @router.post("/klimov", status_code=201)

route/organizations_crud.py

@@ -4,7 +4,7 @@ from typing import Optional
 import uuid
 import io
 
-from bd import make_engine
+from bd import get_session
 
 from bd.tables.organization import Organization
 from route.auth_utils import require_admin_key
@@ -20,9 +20,6 @@ class OrganizationUpdate(BaseModel):
 
 
 
-def get_session():
-    from sqlalchemy.orm import sessionmaker
-    return sessionmaker(bind=make_engine(), future=True)
 
 
 def _org_dict(org: Organization) -> dict:

route/poll_crud.py

@@ -3,7 +3,7 @@ from pydantic import BaseModel
 from typing import List, Optional
 import uuid
 
-from bd import make_engine
+from bd import get_session
 
 from bd.tables.poll import Poll
 from bd.tables.question import Question
@@ -31,9 +31,6 @@ class PollIn(BaseModel):
     questions: Optional[List[QuestionIn]]
 
 
-def get_session():
-    from sqlalchemy.orm import sessionmaker
-    return sessionmaker(bind=make_engine(), future=True)
 
 
 @router.post("/", status_code=201, dependencies=[Depends(require_admin_key)])

route/question_crud.py

@@ -3,7 +3,7 @@ from pydantic import BaseModel
 from typing import Optional
 import uuid
 
-from bd import make_engine
+from bd import get_session
 
 from bd.tables.question import Question
 from bd.tables.poll import Poll
@@ -25,9 +25,6 @@ class QuestionUpdate(BaseModel):
     position: Optional[int]
 
 
-def get_session():
-    from sqlalchemy.orm import sessionmaker
-    return sessionmaker(bind=make_engine(), future=True)
 
 
 @router.post("/", status_code=201, dependencies=[Depends(require_admin_key)])

route/radar_crud.py

@@ -22,7 +22,7 @@ from fastapi.responses import FileResponse
 from pydantic import BaseModel
 from sqlalchemy.orm import Session as SASession
 
-from bd import make_engine
+from bd import get_session
 from bd.tables.response import Response, Answer
 from bd.tables.poll import Poll
 from bd.tables.scale import ScaleDimension, ChoiceScore
@@ -32,9 +32,6 @@ from route.radar_svg_gen import save_radar_svg
 router = APIRouter(tags=["radar"])
 
 
-def get_session():
-    from sqlalchemy.orm import sessionmaker
-    return sessionmaker(bind=make_engine(), future=True)
 
 
 # ---------------------------------------------------------------------------

route/response_crud.py

@@ -3,7 +3,7 @@ from pydantic import BaseModel
 from typing import List, Optional
 import uuid
 
-from bd import make_engine
+from bd import get_session
 
 from bd.tables.poll import Poll
 from bd.tables.question import Question
@@ -26,9 +26,6 @@ class ResponseIn(BaseModel):
     answers: List[AnswerIn]
 
 
-def get_session():
-    from sqlalchemy.orm import sessionmaker
-    return sessionmaker(bind=make_engine(), future=True)
 
 
 @router.post("/{poll_id}/responses", status_code=201)

route/scale_crud.py

@@ -19,7 +19,7 @@ from typing import List, Optional
 from fastapi import APIRouter, HTTPException
 from pydantic import BaseModel
 
-from bd import make_engine
+from bd import get_session
 from bd.tables.poll import Poll
 from bd.tables.choice import Choice
 from bd.tables.scale import ScaleDimension, ChoiceScore
@@ -27,9 +27,6 @@ from bd.tables.scale import ScaleDimension, ChoiceScore
 router = APIRouter(tags=["scale"])
 
 
-def get_session():
-    from sqlalchemy.orm import sessionmaker
-    return sessionmaker(bind=make_engine(), future=True)
 
 
 # ---------------------------------------------------------------------------

route/stats_crud.py

@@ -4,7 +4,7 @@ from sqlalchemy import func
 import json
 import hashlib
 
-from bd import make_engine
+from bd import get_session
 from bd.tables.response import Response
 from bd.tables.poll import Poll
 from bd.tables.group import Group
@@ -26,9 +26,6 @@ def _cache_key(*parts) -> str:
     return hashlib.md5(raw.encode()).hexdigest()
 
 
-def get_session():
-    from sqlalchemy.orm import sessionmaker
-    return sessionmaker(bind=make_engine(), future=True)
 
 
 @router.get("/summary")

route/transfer_crud.py

@@ -24,9 +24,7 @@ from pathlib import Path
 from fastapi import APIRouter, Depends, File, HTTPException, UploadFile
 from fastapi.responses import StreamingResponse
 from sqlalchemy.dialects.postgresql import insert as pg_insert
-from sqlalchemy.orm import sessionmaker
-
-from bd import make_engine
+from bd import get_session
 from bd.tables.organization import Organization
 from bd.tables.group import Group
 from bd.tables.poll import Poll
@@ -61,8 +59,6 @@ _TABLES: list[tuple[str, object]] = [
 ]
 
 
-def _get_session():
-    return sessionmaker(bind=make_engine(), future=True)
 
 
 def _row_to_dict(row) -> dict:
@@ -89,7 +85,7 @@ def _row_to_dict(row) -> dict:
     dependencies=[Depends(require_admin_key)],
 )
 def export_data():
-    Session = _get_session()
+    Session = get_session()
     buf = io.BytesIO()
     counts = {}
 
@@ -147,7 +143,7 @@ def import_data(file: UploadFile = File(...)):
     if fmt not in (EXPORT_FORMAT_VERSION, "1.0"):
         raise HTTPException(status_code=400, detail=f"Неподдерживаемая версия формата: {fmt}")
 
-    Session = _get_session()
+    Session = get_session()
     result = {"inserted": {}, "skipped": {}}
 
     with Session() as session:
@@ -218,7 +214,7 @@ backup_router = APIRouter(prefix="/backup", tags=["backup"])
 )
 def backup_export():
     """Идентично /transfer/export, но в имени файла указан префикс backup_."""
-    Session = _get_session()
+    Session = get_session()
     buf = io.BytesIO()
     counts = {}
 
@@ -279,7 +275,7 @@ def backup_restore(file: UploadFile = File(...)):
     if fmt not in (EXPORT_FORMAT_VERSION, "1.0"):
         raise HTTPException(status_code=400, detail=f"Неподдерживаемая версия формата: {fmt}")
 
-    Session = _get_session()
+    Session = get_session()
     deleted_counts: dict[str, int] = {}
     inserted_counts: dict[str, int] = {}
 

route/users_crud.py

@@ -3,7 +3,7 @@ from pydantic import BaseModel, field_validator
 from typing import Optional
 import uuid
 
-from bd import make_engine
+from bd import get_session
 
 from bd.tables.users import User
 from route.auth_utils import get_current_user, require_admin_key, hash_password
@@ -42,9 +42,6 @@ class UserUpdate(BaseModel):
     organization_id: Optional[str] = None
 
 
-def get_session():
-    from sqlalchemy.orm import sessionmaker
-    return sessionmaker(bind=make_engine(), future=True)
 
 
 def _user_dict(user: User) -> dict: