修改链接池问题

supply_infra/db/session.py

@@ -12,6 +12,10 @@ from supply_infra.db.base import Base
 
 _engine: Any = None
 _SessionLocal: sessionmaker[Session] | None = None
+# Process-local pool override. Used by parallel step workers so we can grow
+# this process's pool without mutating MYSQL_POOL_SIZE_CONTROL (which would
+# re-validate and explode the fleet-wide connection budget).
+_pool_size_override: int | None = None
 
 
 def _set_mysql_session_china_time(
@@ -26,6 +30,12 @@ def _set_mysql_session_china_time(
         cursor.close()
 
 
+def _resolve_pool_size() -> int:
+    if _pool_size_override is not None:
+        return max(1, int(_pool_size_override))
+    return get_infra_settings().selected_mysql_pool_size
+
+
 def get_engine():
     """Lazy-init SQLAlchemy engine (singleton)."""
     global _engine, _SessionLocal
@@ -33,7 +43,7 @@ def get_engine():
         settings = get_infra_settings()
         _engine = create_engine(
             settings.mysql_url,
-            pool_size=settings.selected_mysql_pool_size,
+            pool_size=_resolve_pool_size(),
             max_overflow=settings.mysql_max_overflow,
             pool_timeout=settings.mysql_pool_timeout_seconds,
             pool_recycle=settings.mysql_pool_recycle_seconds,
@@ -64,20 +74,19 @@ def dispose_engine() -> None:
 
 
 def ensure_mysql_pool_capacity(min_connections: int) -> None:
-    """Grow the process-local pool before parallel DB access in the same process."""
+    """Grow the process-local pool before parallel DB access in the same process.
+
+    Must not mutate MYSQL_POOL_SIZE_CONTROL: that setting feeds the fleet-wide
+    connection budget validator. Raising it for a single step (e.g. to 5) makes
+    required connections jump to 60 against a 40 budget and crashes the step.
+    """
+    global _pool_size_override
+
     required = max(1, int(min_connections))
-    settings = get_infra_settings()
-    if settings.selected_mysql_pool_size >= required:
+    if _resolve_pool_size() >= required:
         return
 
-    import os
-
-    role = settings.process_role
-    if role in {"scheduler", "worker", "reconciler", "step"}:
-        os.environ["MYSQL_POOL_SIZE_CONTROL"] = str(required)
-    else:
-        os.environ["MYSQL_POOL_SIZE"] = str(required)
-    get_infra_settings.cache_clear()
+    _pool_size_override = required
     dispose_engine()