13

Yes, Mosquitto does support multiple brokers. Mosquitto uses MQTT Bridges to connect multiple brokers thus routing messages between these mosquitto brokers. This way a bridge between your primary broker to a fallback system can be established. Avoid creating loops though. If both brokers run your clients publish to the primary broker which then publishes ...


12

Some ideas - I've not covered all combinations of with/without username/TLS, hopefully you can see where they are missing. Can a client connect anonymously, no TLS? mosquitto_sub -t test/topic -h <broker address> Can a client connect if it provides a username but no password, no TLS? mosquitto_sub -t test/topic -u <username> -h <broker ...


12

a similar system (extension/plugin) for the mosquitto broker As far as I know there is no plugin/extension for mosquitto broker ( at least no opensource one ) another recommended method that works with mosquitto Well I can say per my experience with Mosquitto broker and AWS IoT, you can just directly subscribe to '#' Reasonable evidence After looking ...


11

This discussion on the openHAB mailing list seems to suggest there's no issue with using # as a subscription to receive all messages: Whilst troubleshooting MQTT devices, it occurred to me that sometimes I wish I could see all MQTT messages that the Mosquitto broker sees, instead of a on a specific topic. Is there a way to do this? ...


10

A few things: The mosquittto_pub and mosquitto_sub commands do not support WebSockets at all. When you run mosquitto from the command line you have to explicitly point to the config file with the -c option mosquitto -v -c /path/to/mosquitto.conf The Windows builds available from the mosquitto.org download pages don't support WebSockets, so the only way ...


10

Turns out there is no broker running on the Arch system whereas installing mosquitto on Raspbian automatically starts it. Simply enable and start the broker. Start the systemd service. systemctl start mosquitto Enable the systemd service to run on boot. systemctl enable mosquitto


10

In .NET the implementation allows to connect one client to one broker, so I'd say why not... MqttClient mqtt; string broker = ini.getData("MQTT", "hostname"); mqtt = new MqttClient(broker); mqtt.MqttMsgPublishReceived += mqtt_received; mqtt.Connect(Guid.NewGuid().ToString()); Thing is, you must manage duplicates in case of a fallback when the other broker ...


10

I think it is important to consider that there are many different use cases for MQTT brokers, as with any piece of software. Handling chat messages for a billion users (many users, relatively low message rate per user) is different to a system with few clients but a high message rate, and they are both different to a home automation system (few clients, low ...


9

Messages are persisted to disk not just held in memory. Look at the autosave_interval and autosave_on_change options for when the messages get written to disk. Source


8

I finally succeeded in finding the correct command on this site. It is: net start mosquitto It can be run from any directory. If you receive the following error: D:\..\MQTT\mosquitto>net start mosquitto System error 5 has occurred. Access is denied. then you need to run the command prompt as an administrator. In case of success the following response ...


8

This is what I do. Following script saved as timestampLog.vbs: Dim str Do While Not WScript.StdIn.AtEndOfStream str = WScript.StdIn.ReadLine WScript.StdErr.WriteLine "[" & now & "]" & str Loop Then I run this from command line: C:\Program Files\mosquitto>mosquitto_sub -t +/# -v | cscript //nologo timestampLog.vbs 2> C:\*USER*\Desktop\...


8

Not directly. You could use an authentication plugin such as mosquitto-auth-plug to dynamically add users to a banned list and then force a disconnection by connecting with a duplicate client id.


8

One way to debug this would be to run mosquitto manually with the same options as your init system is using, then look at the output. For example: mosquitto -v -c <path to config file> Adding -v will ensure that you have verbose logging, regardless of the config file settings.


7

The question here appears to be "should I use MQTT over TCP, or use MQTT over websockets (which also goes over TCP)?" In other words, is "encapsulating MQTT in the websockets protocol a good idea?" This is (almost) entirely down to your application and whether you need websockets support - probably for consuming messages in a browser or for firewall reasons....


7

When you are communicating only inside your network (intranet), using pure TCP will be fine. But if you have to connect to another server, problems will arise. Because most of the modern servers do not allow clients to connect through random ports. They only allow some dedicated ports to connect. That's all. Hence if you have to connect to another server, ...


7

In general, no — there aren't any standards for topic naming beyond the MQTT specifications. There are plenty of opinions about how you should construct your MQTT topics, and not a lot of fixed rules. While this is a bit unsettling when you'd like to know exactly what the best practice is, the lack of strict rules does mean you get a lot of flexibility with ...


6

No, you can no get list of which clients are subscribed to what out of mosquitto. What is most likely here is that HASS is not subscribing rather than mosquitto not publishing to a subscribed client. You can get mosquitto to log each time a subscription request is which made which you could then use to build a list. log_type subscribe, unsubscribe This ...


6

tl;dr - always prefer free libraries to coding it your self (unless you have extreme requirements) Should I use Mosquitto's web sockets or connect clients directly? How long is a piece of string? (YMMV) I can only speak generally, but I always prefer wrapper libraries to raw sockets (or, indeed, to coding anything which I can get for free from a ...


6

On Arch Linux (4.4.37-1-ARCH) with mosquitto 1.4.10-2 and an existing logfile/path with permissions as such I cannot reproduce this error. /var/log/mosquitto $ ls -l -rw-r--r-- 1 mosquitto root 7832 Jan 5 18:15 mosquitto.log If the permissions of the logfile however differ, or it does not exist and the directories permission do not allow mosquitto to write ...


6

The log directory/file should be owned by the mosquitto user or the user that you have setup in the conf file and group. I tried with two conf files one with out log_dest file /var/log/mosquitto/mosquitto.log and one with log destination to file. On my server Mosquitto is running with mosquitto user. With log_dest file /var/log/mosquitto/mosquitto.log ...


6

No, because there is no information about who published the message included in the message header, only the topic and any retained flags. The bridge between the 2 brokers is exactly the same sort of connection as between the a normal client and the broker, it looks to the remote broker just like any other client connection.


6

It seems the "lag" observation is just a side-effect of the logging process, and not a real delay in the data flow. Following the suggestion of @hardillb, I installed tshark on the Raspberry Pi. By observing the request and response packets between the Pi (192.168.0.104) and the ESP8266 (192.168.0.117), I can see that they are within fractions of a second (...


6

No MQTT is a lightweight protocol, it carries nothing in the headers except what is needed (Topic, QOS & Retained flag). It also goes against the pub/sub philosophy that a publisher shouldn't know about who is subscribed to a given topic and a subscriber shouldn't care where the publisher is, just that the information was provided on a given topic. ...


5

I managed to find my mistake. Mistakenly I assumed that the Client ID is a fix field but it is only part of the Payload of the message thus a length-prefix is needed. From the specifications: The payload of the CONNECT Packet contains one or more length-prefixed fields, whose presence is determined by the flags in the variable header. These fields, if ...


5

Maybe stating the obvious, but I think it's important to emphasise that a beginner can't expect to build a secure network. Nothing wrong with learning though. It looks like the primary security in MQTT is implemented at the transport layer, so that should be your focus for real security. I'd be surprised if any automated test suite would be able to ...


5

As @hardlib said, you have to compile mosquitto from sources. It took some trial and error for us to get it working on windows, so here some summary in case it helps somebody. Please don't hesitate to correct it: Prerequisites install Visual Studio install cmake ( latest version is fine ) install OpenSSL to C:\temp\OpenSSL unzip pthreads to C:\pthreads ...


5

No, not without editing the code to remove the log statements from the ping handling code and recompiling the broker.


5

Could you make custom rule by typing the ports (1883 and 8883) and allowing separately with different rules both UDP and TCP on these ports. See: https://technet.microsoft.com/en-us/library/cc947814(v=ws.10).aspx This post says you need the described hack that did not work in your case to change the defaults by program name.


5

As has been suggested in the comments (and now verified by log output) your mosquitto.conf file is not being used. You need to specify the config file when starting the broker with the -c command line argument. mosquitto -c /etc/mosquitto/mosquitto.conf Mosquitto will NOT default to the /etc/mosquitto/mosquitto.conf, if no file is passed it will only ...


5

The solution is to install mosquitto-clients as well. pi@raspberrypi:/ $ apt-get install mosquitto-clients Reading package lists... Done Building dependency tree Reading state information... Done The following additional packages will be installed: libc-ares2 libmosquitto1 The following NEW packages will be installed: libc-ares2 libmosquitto1 mosquitto-...


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