6,465 questions
Best practices
0
votes
4
replies
81
views
(Ab)using ASP.NET Core for non-http message processing?
For learning purposes, I was wondering how the very beginning of the processing of a http message looks and how to change that.
So, as a scenario, imagine the requirement is not to process http but ...
- 1,859
Best practices
0
votes
0
replies
16
views
Am I misusing Azure Event Grid’s MQTT multi‑session support by connecting 100 MQTT clients to a single defined MQTT client in Event Grid?
I have a single machine hosting 100 MQTT clients. Each client has a different EdgeNodeId as required by SparkplugB.
All 100 MQTT clients only publish data to Azure Event Grid. In Event Grid, I’ve ...
- 27
0
votes
0
answers
54
views
android compose mqtt implementation
i'm actually creating an app to control a raspberry pi robot, but for the communication i must use the mqtt protocol, i'm using the davidepianca98 library for that but i don't know where to put the ...
0
votes
1
answer
55
views
Don't get publish() to work in paho.mqtt.client.on_connect thread
I'm struggling to get publish to work in the on_connect thread. The publish called in the main is reaching the broker, but not the ones in the on_connect function.
When running the code below, only &...
Best practices
0
votes
2
replies
29
views
Best way to host multiple EMQX instances per server
I am currently using EMQX as a chat message delivery system paired with a laravel backend for flutter mobile apps. Each client should have his/her own EMQX to provide more security + accurate ...
- 609
4
votes
2
answers
128
views
How can I connect to AWS IoT Core MQTT over WebSocket from browser
Goal
Allow a cognito authenticated user (from web browser) to communicate to IoT Core things/devices
What I Have already done on AWS console:
Created AWS Cognito User Pool User pool - ABC
Created AWS ...
1
vote
0
answers
123
views
paho Android MQTT client does not send PINGREQ to broker when phone screen is off
I have a small android app implementing a foreground service which communicates with mosquito mqtt broker, using paho MQTTClient: org.eclipse.paho:org.eclipse.paho.client.mqttv3:1.2.5
Everything is ...
- 11
0
votes
1
answer
99
views
Prevent multiple subscriptions of same topic in HiveMQ MQTT client
I'm struggling with my MQTT clients to subscribe to a topic without having the topic subscribed multiple times after the client runs for a while. (I also have an issue with the clients not processing ...
- 303
0
votes
1
answer
76
views
AWS MQTT connect from Python - receive not working
I'm learning how to use MQTT on AWS IoT - the goal is to simply publish and receive between AWS IoT MQTT test client and a Python script.
I can successfully publish from my Python code but I am unable ...
- 134
0
votes
0
answers
47
views
Flutter mqtt_client unstable: TCP works initially, WebSocket fails with IP
I’m building a Flutter app that receives MQTT messages from a Mosquitto broker on a Raspberry Pi. I’ve tried both TCP and WebSocket, but neither works reliably.
Setup:
Broker: Mosquitto (Raspberry Pi)...
- 521
3
votes
2
answers
83
views
What happens if the MQTT QoS 2 PUBCOMP packet is lost?
According to the MQTT specification, QoS 2 guarantees exactly-once delivery. It provides the highest level of reliability, but requires a four-step handshake between the publisher and the broker:
...
- 1,324
3
votes
1
answer
117
views
WebSocket Secure connection via Angular Frontend WebApp
I've set up a new dev environment with Nginx as reverse proxy using self signed certificates and a Mosquitto MQTT broker.
I have a NestJS backend using MQTT with following configuration:
private ...
- 528
0
votes
0
answers
130
views
Unsubscribe from topic not working when using persistent session Mqtt
I have a Qt application that uses the qtmqtt module to implement a simple MQTT setup.
I’m running two instances — one as a subscriber and one as a publisher.
In the app, users can right-click on any ...
- 1,324
0
votes
1
answer
124
views
MQTT subscriber doesn’t receive queued messages when publisher uses QoS 0?
I’ve been reading the MQTT documentation, and as I understand it, there are two types of Quality of Service (QoS) levels involved:
Publisher QoS: determines the delivery guarantee between the ...
- 1,324
0
votes
0
answers
95
views
AWS IoT SigV4 presigned WebSocket URL fails when using temporary credentials
I'm generating a SigV4 presigned WebSocket URL for AWS IoT Core using the AWS SDK for Go (v2) and the v4 signer.
It works fine with long-term credentials (we have o Proof of Concept environment), but ...
- 303