Mosquitto MQTT Broker

Dear Steve, trust you are staying away from Covid.
I have setup a RaspberryPi3 running mosquitto, nodeRED,influxdb and Grafana.
Since it is a university project, I enabled TLS on the broker. FYI, i do not have any sensors. So i used MQTT Paho data generator where I’m sending JSON data at an interval of 30 secs.
After doing the TLS config, the broker does not receive any data.
Where is the problem? do i need to import any certificate on the client ? plz help

Hi Steve,
I am doing some kind of load testing. I am trying to establish 1000 concurrent connections to my broker from 5 Linux machines. 80 % connections are successful but 20 % fails with reason connection timed out. Using python to establish these connections. Any suggestions from you get 100 % result.

hi steve l thanks for your great course

I’m using ” eclipse-musquitto ” docker but I have some problem

I created a python file :
import paho.mqtt.client as mqtt
from random import randrange, uniform
import time

mqttBroker = “mqtt”
port = 1883
topic = “test/”

client = mqtt.Client(“test/”)
client.connect(mqttBroker)

while True:
randNumber = uniform(20.0, 21.0)
client.publish(topic, randNumber)
print(“Just published ” + str(randNumber) + ” to Topic “, topic)
time.sleep(1)

and defined 2 cintainer :
sudo docker create network my-net
sudo docker run -d –rm -p 1883:1883 –network my-net –name mqtt-tok tok/mosquitto
sudo docker run –name appc –network my-net app

that app is my image consist of my python file& and after running “sudo docker run –name appc –network my-net app” my program is starting

but I have one problem:
Traceback (most recent call last):
File “/usr/src/app/mqtt_publish.py”, line 10, in
client.connect(mqttBroker)
File “/usr/local/lib/python3.9/site-packages/paho/mqtt/client.py”, line 941, in connect
return self.reconnect()
File “/usr/local/lib/python3.9/site-packages/paho/mqtt/client.py”, line 1075, in reconnect
sock = self._create_socket_connection()
File “/usr/local/lib/python3.9/site-packages/paho/mqtt/client.py”, line 3546, in _create_socket_connection
return socket.create_connection(addr, source_address=source, timeout=self._keepalive)
File “/usr/local/lib/python3.9/socket.py”, line 843, in create_connection
raise err
File “/usr/local/lib/python3.9/socket.py”, line 831, in create_connection
sock.connect(sa)
ConnectionRefusedError: [Errno 111] Connection refused

this ERRORS appears and I don’t know why
could you help me, please?

On my Raspberry Pi (running Mosquitto on Buster) I regularly update using the sudo apt update/upgrade pair. This recent one in early March 2021 snuck in Mosquitto version 2.xx which of course totally disables ALL MQTT traffic causing maximum chaos.
Your brilliant suggestion to allow anonymous users does work and temporarily patches the problem. However, the side effect is that passwords/usernames are no longer needed. Anyone on the network can view all MQTT traffic and insert whatever they want. Thus we went from “User/Pass security” to “Zero security”.
Obviously a long term fix is to study and implement certificates, ACL, TLS, SSL and all the other rabbit hole solutions that can eat up weeks of studying.
My question is this… for the average household IoT user running a Pi, VNC, and 50 or so IoT devices (running Tasmota, Espurna, esp-link, etc) what is the direction to go to get back to at least User/Pass type of security or some kind of certificate installation. Thanks in advance… love your work and easy to read examples and explanations.

Hi Steve,

My field machine remains offline most of the time but should subscribe to Mosquitto broker once online and able to receive all messages published so far from other field devices..
Also once my machine is able to receive those messages, those messages need to be cleared from broker.
Please help me with “How To” for the same.

Regards
Dipankar

Hi
I run Mosquitto on Pi with a connection from ESP32.
I read data with ESP32 from Xiaomi temperature. Everything is fine, but after a while I lose contact with MQTT and I can’t publish anything. I checked and it doesn’t go into the “if (client.connected())” anymore, just in ” else { ”

void publish(const char* addr, char* valueName, char* value) {
char topic[50];
sprintf(topic, “%s/%s/%s”, MQTT_PREFIX, addr, valueName);
if (client.connected()) {
Serial.print(“connected —— “);
// client.publish(topic, value);
client.loop();
// Serial.print(“dupa loop – “);
}
else {
Serial.println(“don’t connected—– “);
// reconnect();
// Serial.println(“Dupa reconectare – “);
}

Best regards
Mihai

Hi Steve,

Thanks for your sharing the information.I have a question when using mosquitto and need your help.

I have mosquitto broker running on the Ubuntu, use 6 embedded devices as the client for publishing information, and another client running on the Ubuntu subscribes to the information.However, some embedded devices will be disconnected after running for 1 week or 2 weeks, and the log infomation,
1589849321: New connection from 192.168.1.114 on port 1883.
1589849322: Socket error on client , disconnecting.

The mosquitto.conf is as follows,
message_size_limit 0
port 1883
max_connections -1
require_certificate false
persistence false

I read a few posts you wrote and found that I did not use a CA certificate. Is this the problem? Can I use mosquitto normally without using this method?

Regards,

Andrew

Hi Steve.
Thanks for your publications. I recently had a question for you and your answer was very helpful. I have another one. I installed Mosquitto broker in Raspberry Pi. After a lot of problems I finally managed to have it running. I have one application (IoTView by an industrial software manufacturer) who is accessing the broker, suscribing and publishing. At the same time I have another application (Web Studio) from the same manufacturer running on a PC, acting as a server who records the information on a database. On the tests, only one of them (IoTView) could run with no problems, while the other one stop working. I have been doing modifications for several months thinking the problem was on the application. Yesterday the manufacturer let me know the problem was on the Broker running on Raspberry Pi. It could not attend two connections at the same time…. Since you know this subject more than anyone I know, I would like your opinion. Is that so? It makes no sense for me that the broker on Raspberry Pi can attend only one connection at the same time. Is there not a parameter whom I can modify to alter this? The manufacturer reccomendation was to switch and install a broker on the Server. The PC running windows.