Client Nodered closed its connection

General
1

Have a broker running on Azure Linux vm and nodered flows to log all the data published.
I do see in mosquitto logs, mqtt in node loses its connection and try to connect back again with message
'Client nodered_a09cd9795fc40663 closed its connection.'

This broker receives 1-sec data from more than 100 topics and all data that comes across are logged locally.

Config of Mosquitto broker:
'''
max_keepalive 65535
max_packet_size 268435455

log_type error
log_type warning
log_type notice
log_type information
connection_messages true

max_queued_messages 0
'''

Any help is appreciated.
Thanks,
Ela

2

Where is the node-red server in relation to the broker? On the same VM or remote?

A disconnect can happen with a duplicate MQTT client ID but that doesn't sound like what is happening here (the symptom would be continuous connections and disconnections).

Could be a timeout issue or even the server going to sleep. Hard to say without more detail.

3

Thanks for your reply. The node-red is running on the same VM and mqtt in nodes that subscribe to topics.Please let me know what details would be helpful.

4

Is node red restarting? Check the node-red log to see.

5

I don't think node-red is restarting. Where can I find logs on nodered ?

6

Normally they can be accessed using journalctl -u nodered , but whether that is the case for an Azure install I have no idea.

You could add an inject node set to fire on startup and make it do something that you can use to know that a restart has occurred, output to a file or persistent context or something similar.

After you see it close the connection does it reconnect?

7

After you see it close the connection does it reconnect?
yes, it reconnected within a few seconds. but since I use Nodered to log live one-second data, its crucial for me to not lose any seconds of data.

I know node-red is single-threaded, so can i create mqtt subscribe node to make the connection with broker on a different port and each of the connections subscribing to different topics? will that help in load balancing?
Thanks for your insight!

8

If node red is restarting then that will not fix the problem, so you need to determine whether that is the case.

9

Please also share your MQTT config node settings. What version of MQTT are you specifying? What Keepalive? Have you specified a client ID - if so, what is it and have you tried without?

You may also need to check your broker settings to see what keepalive it is specifying.