Cloud Run连接Cloud SQL Postgres时间歇性出现pg8000.InterfaceError

• 从Cloud Run连接Cloud SQL托管的PostgreSQL 11时，间歇性出现pg8000.exceptions.InterfaceError错误
• 错误频率：每2-5天发生1-2次
• 部署环境：公网，未使用私有VPC
• 技术栈：Python 3.7 + PostgreSQL 11
• 容器状态：新容器启动前CPU、内存使用率稳定在60%左右
• 连接池状态：未发现数据库或容器连接池耗尽情况

以下是使用Google连接器管理数据库连接池的代码：

class DatabaseConnection:
    _instance = None
    pool: Engine = None

    def __new__(cls):
        if cls._instance is None:
            cls._instance = super(DatabaseConnection, cls).__new__(cls)
        return cls._instance

    @classmethod
    def initialize_pool(cls):
        if cls.pool is None:
            try:
                settings = Settings()

                # Initialize Cloud SQL Connector
                connector = Connector()

                def getconn() -> pg8000.dbapi.Connection:
                    # Use the connector for Cloud SQL
                    return connector.connect(
                        settings.DB_CONNECTION_NAME,
                        "pg8000",
                        user=settings.DB_USER,
                        password=settings.DB_PASSWORD,
                        db=settings.DB_NAME,
                        ip_type=IPTypes.PUBLIC,
                    )

                # Use 'creator' to integrate Cloud SQL Connector with SQLAlchemy
                cls.pool = create_engine(
                    "postgresql+pg8000://",
                    creator=getconn,
                    pool_size=10,
                    max_overflow=1,
                    pool_timeout=30,
                    pool_recycle=1080,
                    pool_pre_ping=True,
                )
                print("Database pool initialized")
            except Exception as e:
                print("Failed to initialize database pool")
                traceback.print_exc()

    @classmethod
    def dispose_pool(cls):
        if cls.pool is not None:
            cls.pool.dispose()
            cls.pool = None
            print("Database pool disposed")

    def get_connection(self):
        if self.pool:
            return self.pool.connect()
        raise SQLAlchemyError("Database pool not initialized")

FastAPI启动/关闭时初始化/销毁连接池：

@app.on_event("startup")
async def startup_event():
    # Initialize the database connection pool
    DatabaseConnection.initialize_pool()


@app.on_event("shutdown")
async def shutdown_event():
    # Dispose of the database connection pool
    DatabaseConnection.dispose_pool()

路由中调用连接的示例：

with DatabaseConnection().get_connection() as postgre_db_connection:
    query_string = text(
        "SELECT * FROM public.brand_data"
    )
    res = postgre_db_connection.execute(query_string)
    query_result_single_row = res.fetchone()

尽管已排查上述状态，但错误的随机性导致复现困难，调试受阻。求有类似经验或相关专业知识的人提供排查思路和解决建议，如需更多日志或细节可随时补充。

内容的提问来源于stack exchange，提问作者doomsday