MQTT Time Out / Random Disconnect

General
1

Hello Folks,

I have recently came across an issue with the MQTT nodes on node Red.

Randomly the mqtt node will disconnect requiring a restart or reboot of Node Red- I was wondering if this has to do with the keep alive time or if its something else but similar?

Any advice would be much appreciated,

Thank you

2

Odd. The connection should recover automatically.

  • What version of node-red are you using?
  • What version of node-js are you using?
  • What broker are you using and where is your broker? (local? Lan? Cloud?)
  • Have you specified a client id in your MQTT config node? If so - is this necessary? is it duplicated elsewhere?

When it is disconnected, do you wait at least 1 minute for reconnection?

3

node.js V12.18.2
node red V1.2.7
AWS broker, lan then through to the cloud.
No client id`s all left blank.

yes I do , but they disconnect and stay off which is the concern.

4

It may be related to the AWS broker.
You could test this by connecting to a local broker & rebooting it to see if node-red reconnects.

Have you considered upgrading to latest V2 and node-js 14?

The latest mqtt nodes can be issued a connect and disconnect action. It might dig you out of a hole.

5

Thank you,

Could you explain what you mean by a local broker? The AWS broker we have is online, so we submit everything via lan to a router which speak to the aws server on line?

I assume the connect reconnect command is on node red, does the mqtt node also tell me when it disconnects?

6

I mean local to your node-red (i.e. mosquitto installed on the same server or a device on your LAN - e.g NOT AWS)

Yes, you would issue a msg to an MQTT node, formatted to tell the node-red client connection to the broker to connect/disconnect (which you can of course automate)

Yes, you can cpature the status of a node using a status node. Therefore you can point a status node at an MQTT node & it will send a message everytime the status of that node changes (essentially providing you with a means to understand the state of the MQTT connection & therefore a means to automate a reconnection)

7

I suggest updating node-red to the latest, there have been significant changes to the MQTT nodes so that in itself may fix or change the symptom.

8

May I ask if the keep alive function on the mqtt node would do anything? I was thinking perhaps the mqtt is timing out due to inactivity hence the keep alive could improve it?

9

I had a Tasmota MQTT configured device which had a bad connection to the 230V supply, it was going on and off many times a day (in batches) due to the intermittent connection. The Node-RED MQTT connection always reconnected.

The MQTT device was installed before April 2020, not sure which version of Node-RED, but this was well before V2 was released, and I had seen no problems. As to the intermittent connection, not sure when that began as I only started tracking the connections last September, and that was for a completely different reason. It was only when I created this flow that I found the problem.

HTH

10

How exactly is this done? The mqtt node doesn`t allow any reconnection command, only the passing of signals to the specific topic ?

11

It's documented in the built in help

But first, I'll refer you back to my first post...

Emphasis on this "The latest mqtt nodes can be issued a connect and disconnect action"

12

Okay , I gathered that, however checking in the palette there doesn`t seem to be a latest node that is capable of this - do you have any node package suggestions? Thank you.

13

You have to upgrade node-red to v2.x latest. Then you get the new capabilities.

14

And, as I said, it is worth doing that first and making sure it still fails.

15

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