[QUESTION] "Connect comms goroutine - error triggered EOF" error

[brunoluizkatz-NETZSCH]

Hi, I'm getting this error from the MQTT lib:

[MQTT-LOG] - [[client]   Connect comms goroutine - error triggered EOF]

The connection options is:

mqttOpts := mqtt.NewClientOptions()
mqttOpts = mqttOpts.SetAutoReconnect(true)
mqttOpts = mqttOpts.SetOnConnectHandler(func(mqtt.Client) {
    // On connect stuff
})
mqttOpts = mqttOpts.SetConnectionLostHandler(func(c mqtt.Client, err error) {
    // On disconnect stuff
})
mqttOpts = mqttOpts.SetClientID(mqttClientID(fmt.Sprintf("%s-%s", clientIDPrefix, h.GetMchID()), time.Now().UnixNano()))
mqttOpts = mqttOpts.SetCleanSession(false)
mqttOpts = mqttOpts.SetKeepAlive(2 * time.Minute) // Sent a ping to the MQTT broker every 2 minutes
mqttOpts = mqttOpts.SetWriteTimeout(2 * time.Second)
mqttOpts = mqttOpts.SetConnectRetry(true)
mqttOpts = mqttOpts.SetPingTimeout(2 * time.Second) // Default is 10 seconds
mqttOpts = mqttOpts.SetConnectRetryInterval(15 * time.Second)
mqttOpts = mqttOpts.AddBroker(fmt.Sprintf("%s://%s:%d", h.connOpts.Protocol, h.connOpts.Host, h.connOpts.Port))
mqttOpts = mqttOpts.SetProtocolVersion(4)
mqttOpts = mqttOpts.SetMaxResumePubInFlight(1) // Max in-flight messages for resume publish
mqttOpts = mqttOpts.SetUsername(h.connOpts.Username)
mqttOpts = mqttOpts.SetPassword(h.connOpts.Password)

I followed the error to the file net.go file at startComms goroutine, specifically at the startOutgoingComms, but it's not triggering the disconnection status and somehow the IsConnected() bool function (at client.go) returns true and the client can't receive or send messages.

The MQTT image instance on EKS version is: eclipse-mosquitto:1.6.10 with SSL enabled

The image is too old or I'm doing some soemthing wrong with the client connection options?

[MattBrittan]

Please enable debug logging and include more info. Broker logs would probably be useful here, suggested info to include with an issue is documented here.

There may be an issue in this library (i.e. state transitions), or it might just be that the connection is dropping soon after it's established (perhaps because the broker is dropping the connection due to an issue with a packet it receives) and then reconnecting immediatly. Currently there is not really enough info to tell (if one of your handlers is blocking then what you are seeing would be expected).

Note that Mosquitto 1.6.10 was released 5 years ago, I'd suggest using a newer version (probably not the issue, but definitly worth using a newer version where possible).

[brunoluizkatz-NETZSCH]

@MattBrittan I will collect some debug info, thanks for the advice.