# Follow up on recent events with MQTT (3.1)

**URL:** <https://discourse.nodered.org/t/follow-up-on-recent-events-with-mqtt-3-1/90988>\
**Category:** General\
**Created:** [15 September 2024 02:24 UTC](https://discourse.nodered.org/t/follow-up-on-recent-events-with-mqtt-3-1/90988 "2024-09-15T02:24:42Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Trying\_to\_learn](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/trying_to_learn/32/28400_2.png) [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Post date:** [15 September 2024 02:24 UTC](https://discourse.nodered.org/t/follow-up-on-recent-events-with-mqtt-3-1/90988/1 "2024-09-15T02:24:42Z")

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Just sharing what I have since _discovered_ regarding MQTT and kept messages.

(No blame is assigned to anyone. I am only telling the story.)

A long time back I needed a queuing system for voice messages.  
Rather than using a `queue` node, the `delay` node was used, and it was set to `rate limit` and a decent enough time set.  
The next message would be then sent either after that time or if a _message_ arrived to tell the node to send the next message.

That all works.

The other day I had/found two problems with MQTT and messages appearing the be backed up and looping _forever_.

I used `MQTT Explorer` and that didn't help the situation.

I was seeing numbers like 300 in the queue.

At the end of things:  
It was no where near that.

It was only like `1` message every _say_ `1` second.

Yet the `delay` node, `MQTT Explorer` and other things were showing these hugely inflated numbers.

I discovered this simply by using a `MQTT IN` node set to that topic.

It was only sending out a very low rate of messages.  
And - to my great relief - was the same one over and over.

# In summary

Be aware if you have such a problem with MQTT messages and you see a large amount of messages _queued_.... It may be only one.

Hope this is useful somewhere to someone.

It is just that WHILE I was trying to get to the bottom of things, it was really _freaking me out_ that there were `300+` messages in the queue, running around because of this _feedback loop_ that somehow happened.

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**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [14 December 2024 02:25 UTC](https://discourse.nodered.org/t/follow-up-on-recent-events-with-mqtt-3-1/90988/2 "2024-12-14T02:25:41Z")

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