fix: clean stale partial database backups

services/db_backup_service.py

@@ -20,6 +20,7 @@ DB_USER = os.environ.get("POSTGRES_USER", "momo")
 DB_NAME = os.environ.get("POSTGRES_DB", "momo_analytics")
 # 保留天數
 RETENTION_DAYS = int(os.environ.get("BACKUP_RETENTION_DAYS", "7"))
+PARTIAL_BACKUP_MIN_AGE_MINUTES = int(os.environ.get("PARTIAL_BACKUP_MIN_AGE_MINUTES", "60"))
 
 
 def _ensure_backup_dir():
@@ -35,6 +36,30 @@ def _remove_partial_backup(filepath: str):
         logger.warning(f"[Backup] 移除不完整備份檔失敗 {filepath}: {exc}")
 
 
+def cleanup_partial_backups(min_age_minutes: int = PARTIAL_BACKUP_MIN_AGE_MINUTES) -> int:
+    """清除失敗後殘留的 0 byte 備份檔，避免監控與人工查檔誤判。"""
+    _ensure_backup_dir()
+    try:
+        min_age_minutes = max(0, int(min_age_minutes))
+    except (TypeError, ValueError):
+        min_age_minutes = 60
+    cutoff = datetime.now() - timedelta(minutes=min_age_minutes)
+    deleted = 0
+    for filepath in glob.glob(os.path.join(BACKUP_DIR, "momo_analytics_*.sql.gz")):
+        try:
+            if os.path.getsize(filepath) != 0:
+                continue
+            mtime = datetime.fromtimestamp(os.path.getmtime(filepath))
+            if mtime > cutoff:
+                continue
+            os.remove(filepath)
+            deleted += 1
+            logger.info(f"[Backup] 已清除 0 byte 不完整備份: {os.path.basename(filepath)}")
+        except Exception as exc:
+            logger.warning(f"[Backup] 清除不完整備份失敗 {filepath}: {exc}")
+    return deleted
+
+
 def _ensure_pg_dump_available() -> str:
     pg_dump_path = shutil.which("pg_dump")
     if pg_dump_path:
@@ -175,10 +200,10 @@ def run_backup() -> dict:
 
 
 def cleanup_old_backups() -> int:
-    """刪除超過保留期限的備份檔，回傳刪除數量"""
+    """刪除不完整與超過保留期限的備份檔，回傳刪除數量。"""
     _ensure_backup_dir()
     cutoff = datetime.now() - timedelta(days=RETENTION_DAYS)
-    deleted = 0
+    deleted = cleanup_partial_backups()
     for f in glob.glob(os.path.join(BACKUP_DIR, "momo_analytics_*.sql.gz")):
         try:
             mtime = datetime.fromtimestamp(os.path.getmtime(f))