mqtt设备定期断开连接

Question

MQTT elements in my Node-RED canvas won't stay connected to a device. If I add a single MQTT element, it will connect every 15 to 18 seconds for approximately 1 second (sometimes up to 10 seconds) before it disconnects. For example here is an extract from the device log.

Token auth succeeded: ClientID='d:pw2bfk:temperature:tempfrontdoor', ClientIP=198.11.231.56 13 Aug 2016 7:53:03 pm
Token auth succeeded: ClientID='d:pw2bfk:temperature:tempfrontdoor', ClientIP=198.11.231.56 13 Aug 2016 7:52:47 pm
Token auth succeeded: ClientID='d:pw2bfk:temperature:tempfrontdoor', ClientIP=198.11.231.56 13 Aug 2016 7:52:41 pm
Token auth succeeded: ClientID='d:pw2bfk:temperature:tempfrontdoor', ClientIP=198.11.231.56 13 Aug 2016 7:52:36 pm
Token auth succeeded: ClientID='d:pw2bfk:temperature:tempfrontdoor', ClientIP=198.11.231.56 13 Aug 2016 7:52:21 pm
Closed connection from 198.11.231.56. The client ID was reused. 13 Aug 2016 7:52:20 pm

I am sure there is a simple issue causing the problem. I've spent many hours to no avail.

Here is the Node-RED canvas -> https://motion.mybluemix.net/red/#

Answer 1

This happens because you have multiple devices using the same MQTT Client ID. If you use MQTT 3.1, make sure each device has unique ID. For MQTT 3.1.1, either make it unique or don't specify it, so that it will be auto-generated.