azure.servicebus.common.errors.ServiceBus

Question

我正在使用适用于 Python 的 Azure 服务总线库从队列中读取消息。x 时间段后我收到以下错误：

Traceback (most recent call last):

  File "/opt/anaconda3/lib/python3.7/site-packages/uamqp/authentication/cbs_auth.py", line 76, in create_authenticator

    self._connection.container_id)

  File "./src/cbs.pyx", line 73, in uamqp.c_uamqp.CBSTokenAuth.__cinit__

ValueError: Unable to open CBS link.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):

  File "/opt/anaconda3/lib/python3.7/site-packages/azure/servicebus/receive_handler.py", line 309, in open

    self._handler.open(connection=self.connection)

  File "/opt/anaconda3/lib/python3.7/site-packages/uamqp/client.py", line 259, in open

    self._build_session()

  File "/opt/anaconda3/lib/python3.7/site-packages/uamqp/client.py", line 214, in _build_session

    on_attach=self._on_attach)

  File "/opt/anaconda3/lib/python3.7/site-packages/uamqp/authentication/cbs_auth.py", line 82, in create_authenticator

    "Please confirm target hostname exists: {}".format(connection.container_id, connection.hostname))

uamqp.errors.AMQPConnectionError: Unable to open authentication session on connection b'SBReceiver-00000000-0000-0000-0000-000000000000'.

Please confirm target hostname exists: b'myhostname.servicebus.windows.net'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):

  File "/opt/anaconda3/lib/python3.7/runpy.py", line 193, in _run_module_as_main

    "__main__", mod_spec)

  File "/opt/anaconda3/lib/python3.7/runpy.py", line 85, in _run_code

    exec(code, run_globals)

  File "/path/to/main.py", line 648, in <module>

    main()

  File "/path/to/main.py", line 631, in main

    run_service_bus()

  File "/path/to/main.py", line 482, in run_service_bus

    with my_client.get_receiver() as queue_receiver:

我认为这里发生的事情是在一段时间后我拥有的令牌过期了。处理这个问题的正确方法是什么？

Answer 1

正如评论中所讨论的，这种情况下的问题很可能是由于网络瞬态错误造成的，这在分布式环境中很正常。大多数情况下，暂时性错误可以通过重试来恢复。不幸的是，在v0.50.x的旧版 python 服务总线 SDK 中，没有开箱即用的重试功能。最新的 V7 SDK中添加了指数回退重试（目前处于预览版，很快将成为 GA）。具体可以参考v0.50到v7的迁移指南。下面是使用 V7 SDK 的接收器代码示例（注意：同步变体，还有异步支持，您可以在广泛的示例列表中查看）。V7 SDK 现在允许您为客户端传递重试参数。虽然默认值一般来说应该足够了。retry_total：允许的重试总数。优先于其他计数。默认值为 10。retry_backoff_factor：在第二次尝试之后在尝试之间应用的退避因子（大多数错误可以通过第二次尝试立即解决，没有延迟）。在固定模式下，重试策略将始终休眠 {backoff Factor}。在“指数”模式下，重试策略将休眠：{退避因子} * (2 ** ({总重试次数} - 1)) 秒。如果 backoff_factor 为 0.1，则重试将在重试之间休眠 [0.0s, 0.2s, 0.4s, ...]。默认值为 0.8。retry_backoff_max：最大回退时间。默认值为 120（以秒为单位）。servicebus_client = ServiceBusClient.from_connection_string(conn_str=CONNECTION_STR, retry_total=10, retry_backoff_factor=1, retry_backoff_max=30)with servicebus_client:    receiver = servicebus_client.get_queue_receiver(queue_name=QUEUE_NAME)    with receiver:        received_msgs = receiver.receive_messages(max_message_count=10, max_wait_time=5)        for msg in received_msgs:            print(str(msg))            msg.complete()