db connection pool bug 처리

app/common/db.py

@@ -15,23 +15,30 @@ async def get_pool() -> aiomysql.Pool:
             user=get_env("MYSQL_USER"),
             password=get_env("MYSQL_PASSWORD"),
             db=get_env("MYSQL_DB"),
-            autocommit=True,
             charset="utf8mb4",
+            minsize=0,
+            maxsize=30,
+            connect_timeout=10,
         )
     return _pool
 
 
+# 쓰기 (INSERT/UPDATE/DELETE)
 async def execute(sql: str, args: tuple = ()) -> int:
     pool = await get_pool()
     async with pool.acquire() as conn:
+        await conn.ping(reconnect=True)
         async with conn.cursor() as cur:
             await cur.execute(sql, args)
+            await conn.commit()
             return cur.lastrowid
 
 
+# 읽기 (SELECT)
 async def fetchone(sql: str, args: tuple = ()) -> dict | None:
     pool = await get_pool()
     async with pool.acquire() as conn:
+        await conn.ping(reconnect=True)
         async with conn.cursor(aiomysql.DictCursor) as cur:
             await cur.execute(sql, args)
             return await cur.fetchone()