I have MQTT explorer installed and running. I am getting 3 message being published every..... so often, that are no longer needed. Their TOPICs are STATUS/(device name) They aren't retained and if I delete them, they come back fairly quickly. I can't find a node (MQTT OUT) with that in the topic …

How many search hits do you get for "myDevicename"? Presumably one hit is where msg.topic is constructed for mqtt, either a function or a change node.

Thanks. That's good to know. Honestly though I guess it was me who didn't name the topic as well a I should. But I guess that is all part of actually learning. I've re-written/structured a fairly big part of the working of my 3 main machines and their comms of what is going on with things. Prob…

[image] Trying_to_learn: How easy is it to install? you already have MQTT v5. Just select the option on the broker config node. (assuming you are using a recent enough broker like Mosquitto v2+ which supports V5)

No, 3.11 :frowning: Ah, Ok, select Version 5 in the drop down. Thanks.

@Steve-Mcl without straying too far off topic... should users be generally using v5 by default now, even if they are not using its advanced features? ...and how does v5 affect external devices, such as Shellie's, etc.

[image] Paul-Reed: should users be generally using v5 by default now It has other benefits like richer error reporting (so when something goes skewwhiff there is a chance you know why). Also, when you sub to multiple same topic, you dont start getting mutiple subs where you expected 1. It is …

[image] Steve-Mcl: If someone REALLY did need to add traceability to your publishers, then MQTT V5 can help here. I really must update all of my flows to use this! Though sadly, MQTT Explorer has never been updated to work with MQTT v5 so it would be hard to easily see the extra data. Prev…

[image] TotallyInformation: Though sadly, MQTT Explorer has never been updated to work with MQTT v5 so it would be hard to easily see the extra data. I still use MQTT explorer but my other go-to is improving lots (has MQTT v5 as well): https://mqttx.app/features

Yes, I've just tried that. But it has a major flaw - it does not show a topic hierarchy like Explorer does which is a pain if you are trying to oversea your whole broker - this is what Explorer excels at. So you can't really monitor anything that has a high volume of updates very easily. Looks like…

[image] TotallyInformation: Looks like I need to revisit some ideas I had previously about creating something in Node-RED. :slight_smile: That would be useful :+1:

No visualisation yet but something to grab whole topic hierarchies - put this into a function node: // Just a safety measure to prevent too much recursion // Change if you have crazy deep topic hierarchies const maxLevels = 9 function doTopic(topicsPart, keys, level = 0) { if (level > maxLeve…

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How can I find out who is publishing a message in MQTT?

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TotallyInformation 6 October 2023 11:12 31

The other thread:

Topic		Replies	Views
Features provided by mqtt and node-red General	4	299	4 May 2022
MQTT devices being reset fairly frequently General	3	333	6 June 2021
Why cant I see any MQTT messages on debug node General	9	277	7 December 2023
Stuck with what's happening with MQTT topics General	12	457	21 November 2025
MQTT Dynamic topic and publish the messages General	3	1070	25 October 2021

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How can I find out *who* is publishing a message in MQTT?

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How can I find out who is publishing a message in MQTT?