Golang中的mqtt客户端偶尔断开连接

Question

I am using paho mqtt client in GO to connect to a broker. Everything works fine for a while, in which I can publish to topics and listen to any subscription. After a while the client loses connection to the broker, for no apparent reason with this log:

[MQTT] ERROR: 2018/09/04 17:31:30 [net] outgoing stopped with error write tcp IP1 -> IP2: write: broken pipe
[MQTT] ERROR: 2018/09/04 17:31:30 [net] logic received from error channel, other components have errored, stopping

I am connecting to the broker like this:

opts := mqtt.NewClientOptions().
    AddBroker(broker).
    SetClientID(fmt.Sprintf("%s-%v", ProgramName, time.Now().Unix())).
    SetUsername(username).
    SetPassword(password).
    SetOrderMatters(true)
if tlsConfig != nil {
    opts.SetTLSConfig(tlsConfig)
}

pahoClient := mqtt.NewClient(opts)
client = &DefaultMQTTClient{
    c:            pahoClient,
    subscribeQoS: subscribeQoS,
    publishQoS:   publishQoS,
    name:         name,
    log: Log.WithPrefix("mqtt").WithFields(logrus.Fields{
        "name":   name,
        "broker": broker,
    }),
}

client.Log().Debug("connecting to mqtt broker")
if err = client.Connect(); err != nil {
    err = client.Log().Trace(err, "failed to connect to mqtt broker")
    return
}
client.Log().Info("established connection with mqtt broker")

And the version of paho that I am using is 1.0.0. Any hint is welcome!