Azure IoT Hub Operations Monitoring

Question

I have an Azure IoT hub that I connect devices to. I want to enable monitoring to monitor devices connecting and disconnecting from the hub.

I've enabled Verbose on Connections in the monitoring categories for my Iot hub:

My devices connect to my Hub and show in Device Explorer:

I then have an Azure Function set to log my data from the Operations Monitoring to an Azure SQL db:

using System;
using System.Configuration;
using System.Data.SqlClient;
using Newtonsoft.Json;

public static void Run(string myEventHubMessage, TraceWriter log)
{
    log.Info(myEventHubMessage);

    try
    {
        var connectionString = ConfigurationManager.ConnectionStrings["iotAzureSQLDb"].ConnectionString;

        log.Info(connectionString);
        var message = JsonConvert.DeserializeObject<MonitoringMessage>(myEventHubMessage);

        using (var connection = new SqlConnection(connectionString))
        {
            var sqlStatement = "insert into [dbo].[DeviceStatuses] " +
                                "(DeviceId, ConnectionStatus, ConnectionUpdateTime)" +
                                "values " +
                                "(@DeviceId, @ConnectionStatus, @ConnectionUpdateTime)";
            using (var dataCommand = new SqlCommand(sqlStatement, connection))
            {
                dataCommand.Parameters.AddWithValue("@ConnectionStatus", message.operationName);
                dataCommand.Parameters.AddWithValue("@DeviceId", message.deviceId);
                dataCommand.Parameters.AddWithValue("@ConnectionUpdateTime", message.time);

                connection.Open();
                dataCommand.ExecuteNonQuery();
                connection.Close();

                log.Info($"Device {message.deviceId} changed state: {message.operationName}");
            }
        }
    }
    catch (Exception ex)
    {
        log.Info(ex.Message);
    }
}

public class MonitoringMessage
{
    public string deviceId { get; set; }
    public string operationName { get; set; }
    public int? durationMs { get; set; }
    public string authType { get; set; }
    public string protocol { get; set; }
    public DateTimeOffset? time { get; set; }
    public string category { get; set; }
    public string level { get; set; }
    public int? statusCode { get; set; }
    public int? statusType { get; set; }
    public string statusDescription { get; set; }
}

If I enable Device Identity Operations in Operations Monitoring, I get create events being logged. So I'm confident the inputs to the function is correct. However, nothing is ever created for Connections???

I can also send messages to my connected devices fine. I'm just seeing no events for connections / disconnections.

I've also tried creating a Stream Analytics and sampling the input for a period where I know I have connections / disconnections and nothing is being found.

Can you use iothub-explorer tool to catch connection/disconnection events? — Rita Han
That's what I'm using an alternative, the problem is you have to poll it every 'x' minutes to get what's connected / disconnected. Whereas if the IoT Monitoring worked properly, I would receive events when a device disconnects. — Stuart

Stuart Stuart · Accepted Answer · 2017-04-20T07:41:45

I have resolved this by forcing my device to connect over MQTT in the dev environment and now I see it connecting and disconnecting.

Unfortunately I can't use MQTT in production.

Does anyone know if Connection / Disconnection events are only possible in MQTT as opposed to AMQP?

Azure IoT Hub Operations Monitoring

3 Answers