MQTT doesn't seem to be happy of late

[Trying_to_learn]

I have had MQTT working for a while now and all is good.

Today I am going around updating flows with new code and I am noticing a lot of MQTT TX nodes are showing disconnected for no reason.

I know it is advisable for me to keep reading any updates which happen, but I don't remember seeing anything said about it.

Actually even some RX nodes are also disconnected.

Yet, others are working fine.

Anyone got any ideas to what is going on?

Thanks in advance.

Just as a P.S.:
I am (now and then) seeing a very brief flash on the node/s. But basically they are "disconnected".

Messages are not getting sent.

[krambriw]

In all my flows I expect & see they are always 'connected' except during a full deploy where they temporarily disconnects and then reconnects. Unless you have made some 'special art work', you should expect to see them connected all the time. First thing I would expect is a network issue

[Trying_to_learn]

Thanks.

Alas no special art work.

I'll just have to keep looking.

[knolleary]

Have you looked at the logs of your mqtt broker to see what's happening?

[Trying_to_learn]

Alas no, because I don't know where they are.

[Trying_to_learn]

Found the file/log.

I shall say sorry here and now that I can't convert the numbers to dates and so am not sure exactly when things are.

But I got this from the latter part of the log file.

I shall do some digging and see what I can find.
But to declare this now:
As far as I know the MQTT has been working fine for most of the time.
As said: I was going through editing other stuff in the flows and noticed the MQTT SEND nodes were not connected.
That is weird as they are on the same machine as the MQTT SERVER.
Other nodes at other parts of the flow/s were on.
Granted there were also nodes which were not connected as well.
But most were.

1546722730: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546722730: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8828.
1546722730: New connection from 192.168.0.99 on port 1883.
1546722730: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546722730: Client mqtt_ad74a89c.5af748 disconnected.
1546722730: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546722745: New connection from 192.168.0.99 on port 1883.
1546722745: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546722745: Client mqtt_3186932e.d5d86c disconnected.
1546722745: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546722745: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8828.
1546722745: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8831.
1546722745: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8834.
1546722745: New connection from 192.168.0.99 on port 1883.
1546722745: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546722745: Client mqtt_ad74a89c.5af748 disconnected.
1546722745: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546722745: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9834.
1546722760: New connection from 192.168.0.99 on port 1883.
1546722760: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546722760: Client mqtt_3186932e.d5d86c disconnected.
1546722760: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546722760: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8831.
1546722760: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8837.
1546722760: New connection from 192.168.0.99 on port 1883.
1546722760: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546722760: Client mqtt_ad74a89c.5af748 disconnected.
1546722760: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546722760: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9834.
1546722760: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9835.
1546722760: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9836.
1546722775: New connection from 192.168.0.99 on port 1883.
1546722775: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546722775: Client mqtt_3186932e.d5d86c disconnected.
1546722775: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546722776: New connection from 192.168.0.99 on port 1883.
1546722776: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546722776: Client mqtt_ad74a89c.5af748 disconnected.
1546722776: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546722776: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9835.
1546722776: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9837.
1546722791: New connection from 192.168.0.99 on port 1883.
1546722791: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546722791: Client mqtt_3186932e.d5d86c disconnected.
1546722791: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546722791: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8840.
1546722791: New connection from 192.168.0.99 on port 1883.
1546722791: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546722791: Client mqtt_ad74a89c.5af748 disconnected.
1546722791: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546722806: New connection from 192.168.0.99 on port 1883.
1546722806: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546722806: Client mqtt_3186932e.d5d86c disconnected.
1546722806: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546722806: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8840.
1546722806: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8843.
1546722806: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8846.
1546722806: New connection from 192.168.0.99 on port 1883.
1546722806: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546722806: Client mqtt_ad74a89c.5af748 disconnected.
1546722806: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546722810: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9838.
1546722821: New connection from 192.168.0.99 on port 1883.
1546722821: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546722821: Client mqtt_3186932e.d5d86c disconnected.
1546722821: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546722821: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8843.
1546722821: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8849.
1546722825: New connection from 192.168.0.99 on port 1883.
1546722825: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546722825: Client mqtt_ad74a89c.5af748 disconnected.
1546722825: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546722825: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9838.
1546722825: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9839.
1546722825: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9840.
1546722840: New connection from 192.168.0.99 on port 1883.
1546722840: New connection from 192.168.0.99 on port 1883.
1546722840: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546722840: Client mqtt_3186932e.d5d86c disconnected.
1546722840: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546722840: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546722840: Client mqtt_ad74a89c.5af748 disconnected.
1546722840: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546722840: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9839.
1546722840: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9841.
1546722855: New connection from 192.168.0.99 on port 1883.
1546722855: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546722855: Client mqtt_3186932e.d5d86c disconnected.
1546722855: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546722855: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8852.
1546722855: New connection from 192.168.0.99 on port 1883.
1546722855: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546722855: Client mqtt_ad74a89c.5af748 disconnected.
1546722855: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546722870: New connection from 192.168.0.99 on port 1883.
1546722870: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546722870: Client mqtt_3186932e.d5d86c disconnected.
1546722870: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546722870: New connection from 192.168.0.99 on port 1883.
1546722870: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8852.
1546722870: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8855.
1546722870: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8858.
1546722870: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546722870: Client mqtt_ad74a89c.5af748 disconnected.
1546722870: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546722870: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9842.
1546722885: New connection from 192.168.0.99 on port 1883.
1546722885: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546722885: Client mqtt_3186932e.d5d86c disconnected.
1546722885: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546722885: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8855.
1546722885: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8861.
1546722885: New connection from 192.168.0.99 on port 1883.
1546722885: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546722885: Client mqtt_ad74a89c.5af748 disconnected.
1546722885: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546722885: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9842.
1546722885: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9843.
1546722885: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9844.
1546722900: New connection from 192.168.0.99 on port 1883.
1546722900: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546722900: Client mqtt_3186932e.d5d86c disconnected.
1546722900: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546722900: New connection from 192.168.0.99 on port 1883.
1546722900: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546722900: Client mqtt_ad74a89c.5af748 disconnected.
1546722900: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546722900: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9843.
1546722900: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9845.
1546722915: New connection from 192.168.0.99 on port 1883.
1546722915: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546722915: Client mqtt_3186932e.d5d86c disconnected.
1546722915: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546722915: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8864.
1546722915: New connection from 192.168.0.99 on port 1883.
1546722915: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546722915: Client mqtt_ad74a89c.5af748 disconnected.
1546722915: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546722930: New connection from 192.168.0.99 on port 1883.
1546722930: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546722930: Client mqtt_3186932e.d5d86c disconnected.
1546722930: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546722930: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8864.
1546722930: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8867.
1546722930: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8870.
1546722930: New connection from 192.168.0.99 on port 1883.
1546722930: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546722930: Client mqtt_ad74a89c.5af748 disconnected.
1546722930: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546722930: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9846.
1546722945: New connection from 192.168.0.99 on port 1883.
1546722945: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546722945: Client mqtt_3186932e.d5d86c disconnected.
1546722945: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546722945: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8867.
1546722945: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8873.
1546722945: New connection from 192.168.0.99 on port 1883.
1546722946: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546722946: Client mqtt_ad74a89c.5af748 disconnected.
1546722946: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546722946: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9846.
1546722946: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9847.
1546722946: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9848.
1546722961: New connection from 192.168.0.99 on port 1883.
1546722961: New connection from 192.168.0.99 on port 1883.
1546722961: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546722961: Client mqtt_3186932e.d5d86c disconnected.
1546722961: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546722961: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546722961: Client mqtt_ad74a89c.5af748 disconnected.
1546722961: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546722962: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9847.
1546722962: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9849.
1546722980: New connection from 192.168.0.99 on port 1883.
1546722980: New connection from 192.168.0.99 on port 1883.
1546722980: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546722980: Client mqtt_3186932e.d5d86c disconnected.
1546722980: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546722980: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546722980: Client mqtt_ad74a89c.5af748 disconnected.
1546722980: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546722980: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8876.
1546722995: New connection from 192.168.0.99 on port 1883.
1546722995: New connection from 192.168.0.99 on port 1883.
1546722995: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546722995: Client mqtt_3186932e.d5d86c disconnected.
1546722995: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546722995: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546722995: Client mqtt_ad74a89c.5af748 disconnected.
1546722995: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546722995: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8876.
1546722995: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8879.
1546722995: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8882.
1546722995: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9850.
1546723010: New connection from 192.168.0.99 on port 1883.
1546723010: New connection from 192.168.0.99 on port 1883.
1546723010: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546723010: Client mqtt_3186932e.d5d86c disconnected.
1546723010: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546723010: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546723010: Client mqtt_ad74a89c.5af748 disconnected.
1546723010: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546723010: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8879.
1546723010: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8885.
1546723010: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9850.
1546723010: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9851.
1546723010: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9852.
1546723025: New connection from 192.168.0.99 on port 1883.
1546723025: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546723025: Client mqtt_3186932e.d5d86c disconnected.
1546723025: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546723025: New connection from 192.168.0.99 on port 1883.
1546723025: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546723025: Client mqtt_ad74a89c.5af748 disconnected.
1546723025: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546723025: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9851.
1546723025: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9853.
1546723040: New connection from 192.168.0.99 on port 1883.
1546723040: New connection from 192.168.0.99 on port 1883.
1546723040: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546723040: Client mqtt_3186932e.d5d86c disconnected.
1546723040: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546723040: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546723040: Client mqtt_ad74a89c.5af748 disconnected.
1546723040: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546723040: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8888.
1546723056: New connection from 192.168.0.99 on port 1883.
1546723056: New connection from 192.168.0.99 on port 1883.
1546723056: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546723056: Client mqtt_3186932e.d5d86c disconnected.
1546723056: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546723056: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546723056: Client mqtt_ad74a89c.5af748 disconnected.
1546723056: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546723056: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8888.
1546723056: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8891.
1546723056: Warning: Received PUBREL from mqtt_3186932e.d5d86c for an unknown packet identifier 8894.
1546723056: Warning: Received PUBREL from mqtt_ad74a89c.5af748 for an unknown packet identifier 9854.
1546723074: New connection from 192.168.0.99 on port 1883.

[Colin]

@Trying_to_learn

Alas no, because I don't know where they are.

To save you the effort of using google or looking up the docs for mosquitto (assuming that is what you are using) then it is probably in /var/log/mosquitto/mosquitto.log

[Trying_to_learn]

I found it as I just posted.

I post the truth at the time. I am asked a question. I reply. That does not mean I always expect an answer.
Google was not really very helpful, because when I entered MQTT LOG I was constantly sent to stuff on how to log data, rather than where the log file is.
Luckily I did find it.

[Trying_to_learn]

I just went to the machine again to look at the flow/s.

The MQTT problem is back similar to the other day.

See attached.
Green are good, Red is bad.

I haven't do anything with that node, so I don't get why it is disconnected.

[Colin]

That certainly looks odd. Have you tried restarting node red just in case something is confused?

[Trying_to_learn]

It has been rebooted many times in the last day because of node updates.

That node (well part of the flow) is duplicated on many machines.
I just powered up another machine and check it. The node on it is connected.
I checked the settings in the other machine's node and in this machine's node.
SAME.

[Colin]

Have you specified a client id in any of the mqtt config nodes? If so then they must all be different.

[Trying_to_learn]

Well,

This is what I see:

(Note red circles and the machines.)

[Colin]

Not the mqtt in and out nodes but the server config nodes, click on the pen next to the server. But first click on the server dropdown in case you have more than one with the same name

[Trying_to_learn]

Ok, shall do.

But, ITMT, I edited the log file and put a "time stamp" in it.

Since then this has been added to the file:

1546726511: Client mqtt_ad74a89c.5af748 already connected, closing old connection.
1546726511: Client mqtt_ad74a89c.5af748 disconnected.
1546726511: New client connected from 192.168.0.99 as mqtt_ad74a89c.5af748 (c1, k20).
1546726511: New connection from 192.168.0.99 on port 1883.
1546726511: Client mqtt_3186932e.d5d86c already connected, closing old connection.
1546726511: Client mqtt_3186932e.d5d86c disconnected.
1546726511: New client connected from 192.168.0.99 as mqtt_3186932e.d5d86c (c1, k20).
1546726526: New connection from 192.168.0.99 on port 1883.

Oh, sorry:
"Server config nodes"?
You mean the drop down arrow on the window I showed - right?
Just with the:

@Colin

Not the mqtt in and out nodes but the server config nodes

You lost me.

Tiny update:
For the sake of trying, I copied the node from the working flow and pasted it in the one where it isn't working.

Edited some bits with the "last will" and "birth cert" but that's all.

Swapped the nodes, deployed, and now BOTH nodes are connected.

[Colin]

@Trying_to_learn

You lost me.

The drop down on the window you posted to the right of 'server' will show a list of servers you have configured. Click on that and you will see whether you have configured more than one. Having selected one click on the pen to the right of that and it will let you edit the config node. In there there is a Client Id field. For you it is probably best to leave it blank.

Actually though I suspect the PUBREL warning is significant but I don't know what that means.

[Trying_to_learn]

This?
#1

Red is the old, Green is the new.
Both the same - bar LWT and BS messages.
#2

[Trying_to_learn]

Silly me.

I said before I edited the mosquitto.log file.

Seems I didn't.

sudo nano mosquitto.log

Though it mentioned the file had been written to while I was editing it: "Do you want to write to file" and I said YES.....

It wasn't done.

So I tried:

pi@TimePi:/var/log/mosquitto $ sudo echo "********** 2019 01 06 09:33" >> mosquitto.log
-bash: mosquitto.log: Permission denied

Not a big deal, but why doesn't that work?
Just so I have a "from here" point in the file.

[knolleary]

If you have multiple entries in the drop-down list of mqtt-broker config nodes pointed at the same broker, I would recommend you pick one, update all your MQTT nodes to use that one config and delete the others.

To make it easier, edit the broker config node and set its 'name' field - that will be used in the drop-down list if set, rather than having a list of identical-looking entries of the same IP address.

[Trying_to_learn]

Thanks.

Yes, that which you describe sounds like what I see.

@knolleary

To make it easier, edit the broker config node and set its 'name' field - that will be used in the drop-down list if set, rather than having a list of identical-looking entries of the same IP address.

Sorry, but I don't understand. (Via edit) Ok, I think I get what you say. It is that field.)

Do you mean this one?
I've just looked and none of the nodes at which I looked have anything in there.

On another thing: So how do I then get rid of the list of the same node in the list after I give the node a name?

And does that mean I have to do it to ALL MQTT nodes?