Publish periodly

[WimmerMarkus]

Hello, have build a .neCore Application and want to Publish DateTimeTopic everySecond, it works for a Time then Stops then the Task without any exception or message. the application need about 75MB of Memory (RAM) when it stops the Memory is 123MB. To reproduce the scene i put the timespan of 10ms, after ~3000Messages stops the CallBack from the Timer. Any Ideas?

public async Task StartAsync(CancellationToken cancellationToken)
        {
            await mqttClient.ConnectAsync(options);
            if (!mqttClient.IsConnected)
            {
                await mqttClient.ReconnectAsync();
            }

            new Timer(BroadcastCall, null, TimeSpan.Zero, TimeSpan.FromMilliseconds(10));
        }

 private async void BroadcastCall(object state)
        {
            messageCounter++;

            var message = new MqttApplicationMessageBuilder()
              .WithTopic("Broadcast/DateTime")
              .WithPayload(new UTF8Encoding().GetBytes(DateTime.Now.ToString("yyyy-MM-ddTHH:mm:ss")))
              .WithExactlyOnceQoS()
              .Build();

            await this.mqttClient.PublishAsync(message);
            logger.LogInformation($"Messages: {messageCounter}");
        }

[chkr1011]

Maybe no solution but please try QoS 1 instead. Then we can see if the QoS 2 implementation is the root cause.

[WimmerMarkus]

what does you mean?

var message = new MqttApplicationMessageBuilder() .WithTopic("Broadcast/DateTime") .WithPayload(new UTF8Encoding().GetBytes(DateTime.Now.ToString("yyyy-MM-ddTHH:mm:ss"))) **.WithQualityOfServiceLevel(MQTTnet.Protocol.MqttQualityOfServiceLevel.AtMostOnce)** .Build(); it takes the same result...

[chkr1011]

Please also put some locking around the usage of the client (or a SemaphoreSlim). The problem is that you are basically starting a task every 10 ms without waiting for finish. So after some time multiple tasks are trying to send data at the same time.

This library is NOT thread safe.

[SeppPenner]

I wouldn't use a timer for this either. Maybe an infinite loop (while(true)) and a Task.Delay instead of the timer could help here:

public async Task RunInBackground(CancellationToken cancellationToken)
{
    await mqttClient.ConnectAsync(options);

    if (!mqttClient.IsConnected)
    {
        await mqttClient.ReconnectAsync();
    }

    var messageCounter = 0;

    while (!cancellationToken.IsCancellationRequested)
    {
        messageCounter++;

        var message = new MqttApplicationMessageBuilder()
            .WithTopic("Broadcast/DateTime")
            .WithPayload(new UTF8Encoding().GetBytes(DateTime.Now.ToString("yyyy-MM-ddTHH:mm:ss")))
            .WithExactlyOnceQoS()
            .Build();

        await this.mqttClient.PublishAsync(message);
        logger.LogInformation($"Messages: {messageCounter}");
        await Task.Delay(1000);
    }
}

[chkr1011]

I close this ticket because I assume it is fixed.