我们正在使用 kafka(0.9.0.0) 来编排不同微服务之间的命令消息。我们发现了一个间歇性问题，即重复的消息被传递到特定主题。下面给出了发生此问题时发生的日志。有人可以帮助理解这个问题吗
Wed, 21-Sep-2016 09:19:07 - WARNING Coordinator unknown during heartbeat -- will retry
Wed, 21-Sep-2016 09:19:07 - WARNING Heartbeat failed; retrying
Wed, 21-Sep-2016 09:19:07 - WARNING <BrokerConnection host=AZSG-D-BOT-DEV4 port=9092> timed out after 40000 ms. Closing connection.
Wed, 21-Sep-2016 09:19:07 - ERROR Fetch to node 1 failed: RequestTimedOutError - 7 - This error is thrown if the request exceeds the user-specified time limit in the request.
Wed, 21-Sep-2016 09:19:07 - INFO Marking the coordinator dead (node 1): None.
Wed, …