B4J Question MQTT sends my message twice

[CR95]

I use a very simple internal MQTT broker

Sub AppStart (Args() As String)
    lstUsers.Initialize
    brokerStarted = False

    If brokerStarted = False Then
        broker.Initialize("", port)
    
        broker.DebugLog = True   'False
        broker.Start
        brokerStarted = True
        users.Initialize
    End If
    Log("Broker started ")   ' & $"Server (${server.GetMyIP})"$)
    StartMessageLoop    ' in order to run/wait indefinitely for events
End Sub

Certainly due to a second installation or a bad usage, the broker now returns messages twice (exactly the same).
I guess that the broker library has an internal list of users and that my name is duplicated in this list ????
On the cloud, I found people having the same issue.

When I install the broker, the log indicates

Persistent store file: /home/dietpi/B4JBridge/tempjars/moquette_store.mapdbr

But this "moquette_store.mapdbr" file does not exist un my tempjars directory

A complete reinstallation of my broker does not solve the issue.

Is there a way to solve this problem ?

 

[Erel]

Are you calling AppStart multiple times? Why is "brokerStarted" needed?

Which QOS are you using for the client?
Make sure that each client uses a unique id.

 

[CR95]

No. I don't call the Broker multiple times; This is a environment that is running since several years !
Yes, QOS = 0 in my calls but I don't need the heavy process of QOS = 2.
Is there a way to "clear" the internal users table of the broker (if this is the way it works) ?

 

[teddybear]

Persistent store file: /home/dietpi/B4JBridge/tempjars/moquette_store.mapdbr

1. This is just a log; this library does not generate persistent store files. It uses MemoryStorageService to save messages, and all messages will be cleared upon process restart.
2. It only supports single user authentication—I'm curious how you managed to implement multiple user authentications.
3. How did you know that MQTT sents your message twice?
4. You could try switching to the jMqttBroker2 library to see if the issue still persists.

 

[Erel]

Is there a way to "clear" the internal users table of the broker (if this is the way it works) ?

No and it isn't needed. The problem is somewhere else.

3. How did you know that MQTT sents your message twice?

Good question. Please provide more information.

And if there is indeed an issue then worth testing with QOS 2.

 

[CR95]

Thanks.

3. How did you know that MQTT sents your message twice

I am not certain that this is the broker which sends the message twice. I use a "spy" which listen to all the MQTT messages but it is not possible to know "who" sends a message.
I use several applications which send and receive MQTT messages and I thought that my issue (twice message) was fom the broker. As Erel said, the problem is somewhere else. I will continue to search by using the Log of the broker