TTI V3 Connector Device EUI Representation

While debugging The Things Industries(TTI) V3 connector on my desktop I had noticed the Device EUI‘s were wrong.

TTI V3 Connector application running as a console application showing incorrect DeviceEUIs

The TTI V3 Connector code…

foreach (V3EndDevice device in endDevices.End_devices)
{
   if (DeviceAzureEnabled(device))
   {
      _logger.LogInformation("Config-ApplicationID:{0} DeviceID:{1} Device EUI:{2}", device.Ids.Application_ids.Application_id, device.Ids.Device_id, BitConverter.ToString(device.Ids.Dev_eui));

      tasks.Add(DeviceRegistration(device.Ids.Application_ids.Application_id, device.Ids.Device_id, _programSettings.ResolveDeviceModelId(device.Ids.Application_ids.Application_id, device.Attributes), stoppingToken));
   }
}

…uses some classes generated by nSwag based on the TheThingsNetwork/LoRaWAN-stack api.swagger.json

public partial class V3EndDeviceIdentifiers 
{
        [Newtonsoft.Json.JsonProperty("device_id", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public string Device_id { get; set; }
    
        [Newtonsoft.Json.JsonProperty("application_ids", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public V3ApplicationIdentifiers Application_ids { get; set; }
    
        /// <summary>The LoRaWAN DevEUI.</summary>
        [Newtonsoft.Json.JsonProperty("dev_eui", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public byte[] Dev_eui { get; set; }
    
        /// <summary>The LoRaWAN JoinEUI (AppEUI until LoRaWAN 1.0.3 end devices).</summary>
        [Newtonsoft.Json.JsonProperty("join_eui", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public byte[] Join_eui { get; set; }
    
        /// <summary>The LoRaWAN DevAddr.</summary>
        [Newtonsoft.Json.JsonProperty("dev_addr", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public byte[] Dev_addr { get; set; }
}

After some research I found references to the underlying problem in TTN and OpenAPI forums. The Dev_addr and Dev_eui fields are Base16(Hexidecimal) encoded binary but are being processed as if they were Base64(mime) encoded.

The TTI connector only displays the Device EUI so I changed the Dev_eui property to a string

public partial class V3EndDeviceIdentifiers 
{
        [Newtonsoft.Json.JsonProperty("device_id", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public string Device_id { get; set; }
    
        [Newtonsoft.Json.JsonProperty("application_ids", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public V3ApplicationIdentifiers Application_ids { get; set; }
    
        /// <summary>The LoRaWAN DevEUI.</summary>
        [Newtonsoft.Json.JsonProperty("dev_eui", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public string Dev_eui { get; set; }

      /// <summary>The LoRaWAN JoinEUI (AppEUI until LoRaWAN 1.0.3 end devices).</summary>
      [Newtonsoft.Json.JsonProperty("join_eui", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public byte[] Join_eui { get; set; }
    
        /// <summary>The LoRaWAN DevAddr.</summary>
        [Newtonsoft.Json.JsonProperty("dev_addr", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        public byte[] Dev_addr { get; set; }
}

I also had to remove the BitConverter.ToString call

foreach (V3EndDevice device in endDevices.End_devices)
{
   if (DeviceAzureEnabled(device))
   {
      _logger.LogInformation("Config-ApplicationID:{0} DeviceID:{1} Device EUI:{2}", device.Ids.Application_ids.Application_id, device.Ids.Device_id, device.Ids.Dev_eui);

      tasks.Add(DeviceRegistration(device.Ids.Application_ids.Application_id, device.Ids.Device_id, _programSettings.ResolveDeviceModelId(device.Ids.Application_ids.Application_id, device.Attributes), stoppingToken));
   }
}

Now the DeviceEUI values are displayed correctly and searching for EndDevices in Azure Application Insights is easier

TTI V3 Connector application running as a console application showing correct DeviceEUIs

Modifying the nSwag generated classes is a really nasty way of fixing the problem but I think this approach is okay as it’s only one field and any other solution I could find was significantly more complex.

Downlink messages NahYeah

While running my The Things IndustriesTTI) gateway I noticed an exception in the logs every so often

Exception of type 'Microsoft.Azure.Devices.Client.Exceptions.DeviceMessageLockLostException' was thrown.

My client subscribes to Message Queue Telemetry Transport Topics(MQTT) (using MQTTNet) for each TTI Application and establishes a connection (using an Azure DeviceClient) for each TTI Device to an Azure IoT Hub(s).

  • v3/{application id}@{tenant id}/devices/{device id}/up
  • v3/{application id}@{tenant id}/devices/{device id}/down/queued
  • v3/{application id}@{tenant id}/devices/{device id}/down/sent
  • v3/{application id}@{tenant id}/devices/{device id}/down/ack
  • v3/{application id}@{tenant id}/devices/{device id}/down/nack
  • v3/{application id}@{tenant id}/devices/{device id}/down/failed

The application subscribes to the queued, ack, nack, and failed topics so the progress of a downlink message can be monitored. For downlink messages the correlation_id “az:LockToken:” contains the message.LockToken so that they can be Abandoned, Completed or Rejected in the MQTT receive messageHandler.

Below is the logging from my application for an odd sequence of messages

*****Nothing much happening for a couple of hours the .'s represent approx 1 second. Wisnode 4 sends roughly every 5 minues

.....................................................................................................................................................................................................................................................................................................................
03:36:08 TTN Uplink message
 ApplicationID: application1
 DeviceID: wisnodetest04
 Port: 5
.....................................................................................................................................................................................................................................................................................................................
03:41:18 TTN Uplink message
 ApplicationID: application1
 DeviceID: wisnodetest04
 Port: 5
...........................................................................
03:42:34 Azure IoT Hub downlink message
 ApplicationID: application1
 DeviceID: wisnodetest04
 LockToken: 57ea0fad-b6b3-492e-b194-10c4ff3e53cb
 Body: vu8=

*****I then started sending 5 messages to Wisnode 5 same payload vu8=, port 71 thru 75 

***** 71 Queued
03:42:34 Queued: v3/application1@tenant1/devices/wisnodetest04/down/queued
 payload: {"end_device_ids":{"device_id":"wisnodetest04","application_ids":{"application_id":"application1"}},
	"correlation_ids":[
"az:LockToken:57ea0fad-b6b3-492e-b194-10c4ff3e53cb",
"as:downlink:01EXX9B1CA4DB68PKCDAK4SS4H"],
	"downlink_queued":{"f_port":71,"frm_payload":"vu8=","confirmed":true,"priority":"NORMAL",
	"correlation_ids":[
"az:LockToken:57ea0fad-b6b3-492e-b194-10c4ff3e53cb",
"as:downlink:01EXX9B1CA4DB68PKCDAK4SS4H"]}}
...
03:42:37 Azure IoT Hub downlink message
 ApplicationID: application1
 DeviceID: wisnodetest04
 LockToken: e2fef28c-fb1f-42cd-bb40-3ad8e6051da9
 Body: vu8=
.

***** 72 Queued
03:42:38 Queued: v3/application1@tenant1/devices/wisnodetest04/down/queued
 payload: {"end_device_ids":{"device_id":"wisnodetest04","application_ids":{"application_id":"application1"}},
	"correlation_ids":[
"az:LockToken:e2fef28c-fb1f-42cd-bb40-3ad8e6051da9",
"as:downlink:01EXX9B4RGSCJ4BN21GHPM85W5"],
	"downlink_queued":{"f_port":72,"frm_payload":"vu8=",
"confirmed":true,"priority":"NORMAL",
	"correlation_ids":[
"az:LockToken:e2fef28c-fb1f-42cd-bb40-3ad8e6051da9",
"as:downlink:01EXX9B4RGSCJ4BN21GHPM85W5"]}}
...
03:42:41 Azure IoT Hub downlink message
 ApplicationID: application1
 DeviceID: wisnodetest04
 LockToken: 70d61d71-9b24-44d2-b54b-7cc08da4d072
 Body: vu8=

***** 73 Queued
03:42:41 Queued: v3/application1@tenant1/devices/wisnodetest04/down/queued
 payload: {"end_device_ids":{"device_id":"wisnodetest04","application_ids":{"application_id":"application1"}},
	"correlation_ids":[
"az:LockToken:70d61d71-9b24-44d2-b54b-7cc08da4d072","as:downlink:01EXX9B800WF7FEP56J3EZ3M8A"],
	"downlink_queued":{"f_port":73,"frm_payload":"vu8=",
"confirmed":true,"priority":"NORMAL",
	"correlation_ids":[
"az:LockToken:70d61d71-9b24-44d2-b54b-7cc08da4d072",
"as:downlink:01EXX9B800WF7FEP56J3EZ3M8A"]}}
...

***** 74 Queued
03:42:45 Azure IoT Hub downlink message
 ApplicationID: application1
 DeviceID: wisnodetest04
 LockToken: 12537728-de4a-4489-ace5-92923e49b8e4
 Body: vu8=
.
03:42:45 Queued: v3/application1@tenant1/devices/wisnodetest04/down/queued
 payload: {"end_device_ids":{"device_id":"wisnodetest04","application_ids":{"application_id":"application1"}},
	"correlation_ids":[
"az:LockToken:12537728-de4a-4489-ace5-92923e49b8e4",
"as:downlink:01EXX9BBWA2YNCN2DFE5FC3BP3"],
	"downlink_queued":{
"f_port":74,"frm_payload":"vu8=",
"confirmed":true,"priority":"NORMAL",
	"correlation_ids":[
"az:LockToken:12537728-de4a-4489-ace5-92923e49b8e4",
"as:downlink:01EXX9BBWA2YNCN2DFE5FC3BP3"]}}
...

***** 75 Queued
03:42:48 Azure IoT Hub downlink message
 ApplicationID: application1
 DeviceID: wisnodetest04
 LockToken: 388efc11-4514-406e-8147-9109289095f4
 Body: vu8=

03:42:49 Queued: v3/application1@tenant1/devices/wisnodetest04/down/queued
 payload: {"end_device_ids":{"device_id":"wisnodetest04","application_ids":{"application_id":"application1"}},
	"correlation_ids":[
"az:LockToken:388efc11-4514-406e-8147-9109289095f4",
"as:downlink:01EXX9BFCM2G51EPYNWGDWPS0N"],
	"downlink_queued":{"f_port":75,"frm_payload":"vu8=",
"confirmed":true,"priority":"NORMAL",
	"correlation_ids":[
"az:LockToken:388efc11-4514-406e-8147-9109289095f4",
"as:downlink:01EXX9BFCM2G51EPYNWGDWPS0N"]}}

***** Waiting for Wisniode
..........................................................................................................................................................................
03:47:18 TTN Uplink message
 ApplicationID: application1
 DeviceID: wisnodetest04
 Port: 5

***** Waiting for Wisniode again, I think might have been such a long delay becuase TTI didn't get
..........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
***** 71 Nack'd
03:56:52 Nack: v3/application1@tenant1/devices/wisnodetest04/down/nack
 payload: {"end_device_ids":{"device_id":"wisnodetest04","application_ids":{"application_id":"application1"},
	"dev_eui":"60C5A8FFFE781691","join_eui":"70B3D57ED0000000","dev_addr":"26083BE1"},
	"correlation_ids":[
"as:downlink:01EXX9B1CA4DB68PKCDAK4SS4H",
"as:up:01EXXA572VHN7X7G5KFTHBQPNG",
"az:LockToken:57ea0fad-b6b3-492e-b194-10c4ff3e53cb",
"gs:conn:01EXRPTTFGFNTRGH7V8FTC3R0S",
"gs:up:host:01EXRPTTFTEXBNV87KZFYFWP5V",
"gs:uplink:01EXXA56VPK14XG5S8JB9Q0V0X",
"ns:uplink:01EXXA56VYCHGGPPN1K77REMNM",
"rpc:/ttn.lorawan.v3.GsNs/HandleUplink:01EXXA56VRG6811HRCF803VJ34"],
	"received_at":"2021-02-07T03:56:53.211893610Z",
	"downlink_nack":{
"session_key_id":"AXd6GPmneD3dKVoArcS36g==",
"f_port":71,"f_cnt":35,
"frm_payload":"vu8=",
"confirmed":true,"priority":"NORMAL",
	"correlation_ids":[
"az:LockToken:57ea0fad-b6b3-492e-b194-10c4ff3e53cb",
"as:downlink:01EXX9B1CA4DB68PKCDAK4SS4H"]}}

 Found az:LockToken:

03:56:52 TTN Uplink message
 ApplicationID: application1
 DeviceID: wisnodetest04
 Port: 5

03:56:52 Azure IoT Hub downlink message
 ApplicationID: application1
 DeviceID: wisnodetest04
 LockToken: 856f5a9b-bc37-435c-8de9-19d2213999f8
 Body: vu8=

03:56:53 Queued: v3/application1@tenant1/devices/wisnodetest04/down/queued
 payload: {
"end_device_ids":{"device_id":"wisnodetest04","application_ids":{"application_id":"application1"},
	"correlation_ids":[
"az:LockToken:856f5a9b-bc37-435c-8de9-19d2213999f8",
"as:downlink:01EXXA57JJWWYEDX3Z55TNSTP5"],
	"downlink_queued":{"f_port":71,
"frm_payload":"vu8=",
"confirmed":true,"priority":"NORMAL",
	"correlation_ids":
["az:LockToken:856f5a9b-bc37-435c-8de9-19d2213999f8",
"as:downlink:01EXXA57JJWWYEDX3Z55TNSTP5"]}}

......
***** 71 Ack'd
03:56:58 Ack: v3/application1@tenant1/devices/wisnodetest04/down/ack
 payload: {"end_device_ids":{"device_id":"wisnodetest04","application_ids":{"application_id":"application1"},
	"dev_eui":"60C5A8FFFE781691","join_eui":"70B3D57ED0000000","dev_addr":"26083BE1"},
	"correlation_ids":[
"as:downlink:01EXX9B1CA4DB68PKCDAK4SS4H",
"as:up:01EXXA5D45E77S19TXEV1E4GAJ",
"az:LockToken:57ea0fad-b6b3-492e-b194-10c4ff3e53cb",
"gs:conn:01EXRPTTFGFNTRGH7V8FTC3R0S",
"gs:up:host:01EXRPTTFTEXBNV87KZFYFWP5V",
"gs:uplink:01EXXA5CV73THH2RKEAC2T9MDP",
"ns:uplink:01EXXA5CVDCWPFBTXGGGB3T02W",
"rpc:/ttn.lorawan.v3.GsNs/HandleUplink:01EXXA5CVDEXDFBPYXC0J01Q3E"],
	"received_at":"2021-02-07T03:56:59.397330003Z",
	"downlink_ack":{
"session_key_id":"AXd6GPmneD3dKVoArcS36g==",
"f_port":71,"f_cnt":36,"frm_payload":"vu8=",
"confirmed":true,"priority":"NORMAL",
	"correlation_ids":[
"az:LockToken:57ea0fad-b6b3-492e-b194-10c4ff3e53cb",
"as:downlink:01EXX9B1CA4DB68PKCDAK4SS4H"]}}

 Found az:LockToken:
Exception of type 'Microsoft.Azure.Devices.Client.Exceptions.DeviceMessageLockLostException' was thrown.

03:56:59 TTN Uplink message
 ApplicationID: application1
 DeviceID: wisnodetest04
 Port: 0
......
03:57:04 Ack: v3/application1@tenant1/devices/wisnodetest04/down/ack
 payload: {"end_device_ids":{"device_id":"wisnodetest04","application_ids":{"application_id":"application1"},
"dev_eui":"60C5A8FFFE781691","join_eui":"70B3D57ED0000000","dev_addr":"26083BE1"},
"correlation_ids":[
"as:downlink:01EXX9B4RGSCJ4BN21GHPM85W5",
"as:up:01EXXA5K2FWGP9DGD7THWZ8HNR",
"az:LockToken:e2fef28c-fb1f-42cd-bb40-3ad8e6051da9",
"gs:conn:01EXRPTTFGFNTRGH7V8FTC3R0S",
"gs:up:host:01EXRPTTFTEXBNV87KZFYFWP5V",
"gs:uplink:01EXXA5JVDR102TKCWQ77P4YYF",
"ns:uplink:01EXXA5JVGNGMZN33FNT47G6PF",
"rpc:/ttn.lorawan.v3.GsNs/HandleUplink:01EXXA5JVGJFFQVEWX2M1XSFKK"],
"received_at":"2021-02-07T03:57:05.487910418Z","downlink_ack":{"session_key_id":"AXd6GPmneD3dKVoArcS36g==",
"f_port":72,"f_cnt":37,
"frm_payload":"vu8=",
"confirmed":true,"priority":"NORMAL","correlation_ids":
["az:LockToken:e2fef28c-fb1f-42cd-bb40-3ad8e6051da9","as:downlink:01EXX9B4RGSCJ4BN21GHPM85W5"]}}

The sequence of messages is a bit odd, in the Azure DeviceClient ReceiveMessageHandler a downlink message is published, then a queued message is received, then a nak and finally an ack, The exception was because my client was trying to Complete the delivery of a message that had already been Abandoned.

Application Insights & Configuration

As part of my The Things IndustriesTTI) Integration my current approach is to use an Azure web job and configure the Azure App Service host so it doesn’t get shutdown after a period of inactivity. This so my application won’t have to repeatedly use the TTI API to request the Application and Device configuration information to reload the cache (still not certain if this is going to be implemented with a ConcurrentDictionary or ObjectCache).

namespace devMobile.TheThingsNetwork.WorkerService
{
   using System.Collections.Generic;

   public class AzureDeviceProvisiongServiceSettings
   {
      public string IdScope { get; set; }
      public string GroupEnrollmentKey { get; set; }
   }

   public class AzureSettings
   {
      public string IoTHubConnectionString { get; set; }
      public AzureDeviceProvisiongServiceSettings DeviceProvisioningServiceSettings { get; set; }
   }

   public class ApplicationSetting
   {
      public AzureSettings AzureSettings { get; set; }

      public string MQTTAccessKey { get; set; }

      public byte? ApplicationPageSize { get; set; }

      public bool? DeviceIntegrationDefault { get; set; }
      public byte? DevicePageSize { get; set; }
   }

   public class TheThingsIndustries
   {
      public string MqttServerName { get; set; }
      public string MqttClientName { get; set; }

      public string Tennant { get; set; }
      public string ApiBaseUrl { get; set; }
      public string ApiKey { get; set; }

      public bool ApplicationIntegrationDefault { get; set; }
      public byte ApplicationPageSize { get; set; }

      public bool DeviceIntegrationDefault { get; set; }
      public byte DevicePageSize { get; set; }
   }

   public class ProgramSettings
   {
      public TheThingsIndustries TheThingsIndustries { get; set; }

      public AzureSettings AzureSettingsDefault { get; set; }

      public Dictionary<string, ApplicationSetting> Applications { get; set; }
   }
}

The amount of configuration required to support multiple TTI Applications containing many Devices is also starting to get out of hand.

I need to subscribe to a Message Queue Telemetry Transport Topics(MQTT using MQTTNet) for each Application and establish a connection (using an Azure DeviceClient) for each TTI Device to the configured Azure IoT Hub(s).

  • v3/{application id}@{tenant id}/devices/{device id}/up
  • v3/{application id}@{tenant id}/devices/{device id}/down/queued
  • v3/{application id}@{tenant id}/devices/{device id}/down/sent
  • v3/{application id}@{tenant id}/devices/{device id}/down/ack
  • v3/{application id}@{tenant id}/devices/{device id}/down/nack
  • v3/{application id}@{tenant id}/devices/{device id}/down/failed

The Azure DeviceClient has to be configured and OpenAsync called just before/after subscribing to the TTI Application /up topic so the SendEventAsync method can be called to send messages to the configured Azure IoT Hub(s). For downlink messages the SetReceiveMessageHandler method will need to be called just before/after subscribing to ../down/queued, ../down/sent,../down/ack,…/down/nack and ,…/down/failed downlink topics.

The ordering of downloading the Application and Device configuration so downlink messages can be sent and uplink message received as soon as possible (so no messages are lost) is important. I have considered making the downlink process multi-threaded so API calls are made concurrently but I’m not certain the additional complexity would be worth it, especially in initial versions.

I’m also currently not certain about how to register my program for Application and Device registry changes so it doesn’t have to be restarted when configuration changes. I have also considered reverting to an HTTP Integration so that I could use Azure Storage queues to buffer uplink and downlink messages. This may also introduce ordering issues when multiple threads are created for Azure Queue Trigger functions to process a message backlog.

For debugging the application and monitoring in production I was planning on using the Apache Log4Net library but now I’m not certain the additional configuration complexity and dependencies are worth it. The built in Microsoft.Extensions.Logging library with Azure Application Insights integration looks like a “light weight” alternative with sufficient functionality .

protected override async Task ExecuteAsync(CancellationToken stoppingToken)
{
   while (!stoppingToken.IsCancellationRequested)
   {
      _logger.LogDebug("Debug worker running at: {time}", DateTimeOffset.Now);
      _logger.LogInformation("Info worker running at: {time}", DateTimeOffset.Now);
      _logger.LogWarning("Warning worker running at: {time}", DateTimeOffset.Now);
      _logger.LogError("Error running at: {time}", DateTimeOffset.Now);

      using (_logger.BeginScope("TheThingsIndustries configuration"))
      {
         _logger.LogInformation("Tennant: {0}", _programSettings.TheThingsIndustries.Tennant);
         _logger.LogInformation("ApiBaseUrl: {0}", _programSettings.TheThingsIndustries.ApiBaseUrl);
         _logger.LogInformation("ApiKey: {0}", _programSettings.TheThingsIndustries.ApiKey);

         _logger.LogInformation("ApplicationPageSize: {0}", _programSettings.TheThingsIndustries.ApplicationPageSize);
         _logger.LogInformation("DevicePageSize: {0}", _programSettings.TheThingsIndustries.DevicePageSize);

         _logger.LogInformation("ApplicationIntegrationDefault: {0}", _programSettings.TheThingsIndustries.ApplicationIntegrationDefault);
         _logger.LogInformation("DeviceIntegrationDefault: {0}", _programSettings.TheThingsIndustries.DeviceIntegrationDefault);

         _logger.LogInformation("MQTTServerName: {0}", _programSettings.TheThingsIndustries.MqttServerName);
         _logger.LogInformation("MQTTClientName: {0}", _programSettings.TheThingsIndustries.MqttClientName);
      }

      using (_logger.BeginScope("Azure default configuration"))
      {
         if (_programSettings.AzureSettingsDefault.IoTHubConnectionString != null)
         {
            _logger.LogInformation("AzureSettingsDefault.IoTHubConnectionString: {0}", _programSettings.AzureSettingsDefault.IoTHubConnectionString);
         }

         if (_programSettings.AzureSettingsDefault.DeviceProvisioningServiceSettings != null)
         {
            _logger.LogInformation("AzureSettings.DeviceProvisioningServiceSettings.IdScope: {0}", _programSettings.AzureSettingsDefault.DeviceProvisioningServiceSettings.IdScope);
            _logger.LogInformation("AzureSettings.DeviceProvisioningServiceSettings.GroupEnrollmentKey: {0}", _programSettings.AzureSettingsDefault.DeviceProvisioningServiceSettings.GroupEnrollmentKey);
         }
      }
    
      foreach (var application in _programSettings.Applications)
      {
         using (_logger.BeginScope(new[] { new KeyValuePair<string, object>("Application", application.Key)}))
         {
            _logger.LogInformation("MQTTAccessKey: {0} ", application.Value.MQTTAccessKey);

            if (application.Value.ApplicationPageSize.HasValue)
            {
               _logger.LogInformation("ApplicationPageSize: {0} ", application.Value.ApplicationPageSize.Value);
            }

            if (application.Value.DeviceIntegrationDefault.HasValue)
            {
               _logger.LogInformation("DeviceIntegation: {0} ", application.Value.DeviceIntegrationDefault.Value);
            }

            if (application.Value.DevicePageSize.HasValue)
            {
               _logger.LogInformation("DevicePageSize: {0} ", application.Value.DevicePageSize.Value);
            }

            if (application.Value.AzureSettings.IoTHubConnectionString != null)
            {
               _logger.LogInformation("AzureSettings.IoTHubConnectionString: {0} ", application.Value.AzureSettings.IoTHubConnectionString);
            }

            if (application.Value.AzureSettings.DeviceProvisioningServiceSettings != null)
            {
               _logger.LogInformation("AzureSettings.DeviceProvisioningServiceSettings.IdScope: {0} ", application.Value.AzureSettings.DeviceProvisioningServiceSettings.IdScope);
               _logger.LogInformation("AzureSettings.DeviceProvisioningServiceSettings.GroupEnrollmentKey: {0} ", application.Value.AzureSettings.DeviceProvisioningServiceSettings.GroupEnrollmentKey);
            }
         }
      }

      await Task.Delay(300000, stoppingToken);
   }
}

The logging information formatting is sufficiently readable when running locally

Extensive use of the BeginScope method to include additional meta-data on logged records should make debugging easier.

This long post is to explain some of my design decisions and which ones are still to be decided

The Things Network HTTP Integration Part10

Assembling the components

After a series of articles exploring how portions of solution could be built

I now had working code for receiving The Things Network(TTN) HTTP integration JSON messages with an Azure Function using an HTTPTrigger. (secured with an APIKey) and then putting them into an Azure Storage Queue for processing. This code was intentionally kept as small and as simple as possible so there was less to go wrong. The required configuration is also minimal.

HTTP Endpoint handler application

In the last couple of posts I had been building an Azure Function with a QueueTrigger to process the uplink messages. The function used custom bindings so that the CloudQueueMessage could be accessed, and load the Azure Storage account plus queue name from configuration. I’m still using classes generated by JSON2CSharp (with minimal modifications) for deserialising the payloads with JSON.Net.

The message processor Azure Function uses a ConcurrentCollection to store AzureDeviceClient objects constructed using the information returned by the Azure Device Provisioning Service(DPS). This is so the DPS doesn’t have to be called for the connection details for every message.(When the Azure function is restarted the dictionary of DeviceClient objects has to be repopulated). If there is a backlog of messages the message processor can process more than a dozen messages concurrently so the telemetry events displayed in an application like Azure IoT Central can arrive out of order.

The solution uses DPS Group Enrollment with Symmetric Key Attestation so Azure IoT Hub devices can be “automagically” created when a message from a new device is processed. The processing code is multi-thread and relies on many error conditions being handled by the Azure Function retry mechanism. After a number of failed retries the messages are moved to a poison queue. Azure Storage Explorer is a good tool for viewing payloads and moving poison messages back to the processing queue.

public static class UplinkMessageProcessor
{
   static readonly ConcurrentDictionary<string, DeviceClient> DeviceClients = new ConcurrentDictionary<string, DeviceClient>();

   [FunctionName("UplinkMessageProcessor")]
   public static async Task Run(
      [QueueTrigger("%UplinkQueueName%", Connection = "AzureStorageConnectionString")]
      CloudQueueMessage cloudQueueMessage, // Used to get CloudQueueMessage.Id for logging
      Microsoft.Azure.WebJobs.ExecutionContext context,
      ILogger log)
   {
      PayloadV5 payloadObect;
      DeviceClient deviceClient = null;
      DeviceProvisioningServiceSettings deviceProvisioningServiceConfig;

      string environmentName = Environment.GetEnvironmentVariable("ENVIRONMENT");

      // Load configuration for DPS. Refactor approach and store securely...
      var configuration = new ConfigurationBuilder()
      .SetBasePath(context.FunctionAppDirectory)
      .AddJsonFile($"appsettings.json")
      .AddJsonFile($"appsettings.{environmentName}.json")
      .AddEnvironmentVariables()
      .Build();

      // Load configuration for DPS. Refactor approach and store securely...
      try
      {
         deviceProvisioningServiceConfig = (DeviceProvisioningServiceSettings)configuration.GetSection("DeviceProvisioningService").Get<DeviceProvisioningServiceSettings>(); ;
      }
      catch (Exception ex)
      {
         log.LogError(ex, $"Configuration loading failed");
         throw;
      }

      // Deserialise uplink message from Azure storage queue
      try
      {
         payloadObect = JsonConvert.DeserializeObject<PayloadV5>(cloudQueueMessage.AsString);
      }
      catch (Exception ex)
      {
         log.LogError(ex, $"MessageID:{cloudQueueMessage.Id} uplink message deserialisation failed");
         throw;
      }

      // Extract the device ID as it's used lots of places
      string registrationID = payloadObect.hardware_serial;

      // Construct the prefix used in all the logging
      string messagePrefix = $"MessageID: {cloudQueueMessage.Id} DeviceID:{registrationID} Counter:{payloadObect.counter} Application ID:{payloadObect.app_id}";
      log.LogInformation($"{messagePrefix} Uplink message device processing start");

      // See if the device has already been provisioned
      if (DeviceClients.TryAdd(registrationID, deviceClient))
      {
         log.LogInformation($"{messagePrefix} Device provisioning start");

         string enrollmentGroupSymmetricKey = deviceProvisioningServiceConfig.EnrollmentGroupSymmetricKeyDefault;

         // figure out if custom mapping for TTN applicationID
         if (deviceProvisioningServiceConfig.ApplicationEnrollmentGroupMapping != null)
        {
            deviceProvisioningServiceConfig.ApplicationEnrollmentGroupMapping.GetValueOrDefault(payloadObect.app_id, deviceProvisioningServiceConfig.EnrollmentGroupSymmetricKeyDefault);
         }

         // Do DPS magic first time device seen
         await DeviceRegistration(log, messagePrefix, deviceProvisioningServiceConfig.GlobalDeviceEndpoint, deviceProvisioningServiceConfig.ScopeID, enrollmentGroupSymmetricKey, registrationID);
      }

      // Wait for the Device Provisioning Service to complete on this or other thread
      log.LogInformation($"{messagePrefix} Device provisioning polling start");
      if (!DeviceClients.TryGetValue(registrationID, out deviceClient))
      {
         log.LogError($"{messagePrefix} Device provisioning polling TryGet before while failed");

         throw new ApplicationException($"{messagePrefix} Device provisioning polling TryGet before while failed");
      }

      while (deviceClient == null)
      {
         log.LogInformation($"{messagePrefix} provisioning polling delay");
         await Task.Delay(deviceProvisioningServiceConfig.DeviceProvisioningPollingDelay);

         if (!DeviceClients.TryGetValue(registrationID, out deviceClient))
         {
            log.LogError($"{messagePrefix} Device provisioning polling TryGet while loop failed");

            throw new ApplicationException($"{messagePrefix} Device provisioning polling TryGet while loopfailed");
         }
      }

      // Assemble the JSON payload to send to Azure IoT Hub/Central.
      log.LogInformation($"{messagePrefix} Payload assembly start");
      JObject telemetryEvent = new JObject();
      try
      {
         JObject payloadFields = (JObject)payloadObect.payload_fields;
         telemetryEvent.Add("HardwareSerial", payloadObect.hardware_serial);
         telemetryEvent.Add("Retry", payloadObect.is_retry);
         telemetryEvent.Add("Counter", payloadObect.counter);
         telemetryEvent.Add("DeviceID", payloadObect.dev_id);
         telemetryEvent.Add("ApplicationID", payloadObect.app_id);
         telemetryEvent.Add("Port", payloadObect.port);
         telemetryEvent.Add("PayloadRaw", payloadObect.payload_raw);
         telemetryEvent.Add("ReceivedAt", payloadObect.metadata.time);

         // If the payload has been unpacked in TTN backend add fields to telemetry event payload
         if (payloadFields != null)
         {
            foreach (JProperty child in payloadFields.Children())
            {
               EnumerateChildren(telemetryEvent, child);
            }
         }
      }
      catch (Exception ex)
      {
         if (DeviceClients.TryRemove(registrationID, out deviceClient))
         {
            log.LogWarning($"{messagePrefix} TryRemove payload assembly failed");
         }

         log.LogError(ex, $"{messagePrefix} Payload assembly failed");
         throw;
      }

      // Send the message to Azure IoT Hub/Azure IoT Central
      log.LogInformation($"{messagePrefix} Payload SendEventAsync start");
      try
      {
         using (Message ioTHubmessage = new Message(Encoding.ASCII.GetBytes(JsonConvert.SerializeObject(telemetryEvent))))
         {
            // Ensure the displayed time is the acquired time rather than the uploaded time. esp. importan for messages that end up in poison queue
            ioTHubmessage.Properties.Add("iothub-creation-time-utc", payloadObect.metadata.time.ToString("s", CultureInfo.InvariantCulture));
            await deviceClient.SendEventAsync(ioTHubmessage);
         }
      }
      catch (Exception ex)
      {
         if (DeviceClients.TryRemove(registrationID, out deviceClient))
         {
            log.LogWarning($"{messagePrefix} TryRemove SendEventAsync failed");
         }

         log.LogError(ex, $"{messagePrefix} SendEventAsync failed");
         throw;
      }

   log.LogInformation($"{messagePrefix} Uplink message device processing completed");
   }
}

There is also support for using a specific GroupEnrollment based on the application_id in the uplink message payload.

"DeviceProvisioningService": {
      "GlobalDeviceEndpoint": "global.azure-devices-provisioning.net",
      "ScopeID": "",
      "EnrollmentGroupSymmetricKeyDefault": "TopSecretKey",
      "DeviceProvisioningPollingDelay": 500,
      "ApplicationEnrollmentGroupMapping": {
         "Application1": "TopSecretKey1",
         "Application2": "TopSecretKey2"
      }
   }

In addition to the appsettings.json there is configuration for application insights, uplink message queue name and Azure Storage connection strings. The “Environment” setting is important as it specifies what appsettings.json file should be used if code is being debugged etc..

TTN Integration uplink message processor configuration

The deployed solution application consists of Azure IoTHub and DPS instances. There are two Azure functions, one for putting the messages from the TTN into a queue the other is for processing them. The Azure Functions are hosted in an Azure AppService plan.

Azure solution deployment

An Azure Storage account is used for the queue and Azure Function synchronisation information and Azure Application Insights is used to monitor the solution.

NLog and Application Insights Revisited

Just a few small changes to my NLog sample logging to Azure Application Insights.

I modified the application so I could provide the InstrumentationKey via the command line or the ApplicationInsights.Config file.(I have a minimalist config for this sample)

namespace devMobile.Azure.ApplicationInsightsNLogClient
{
   class Program
   {
      private static Logger log = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType.ToString());

      static void Main(string[] args)
      {
         if ((args.Length != 0) && (args.Length != 1))
         {
            Console.WriteLine("Usage ApplicationInsightsNLogClient");
            Console.WriteLine("      ApplicationInsightsNLogClient <instrumentationKey>");
            return;
         }

         if (args.Length == 1)
         {
            TelemetryConfiguration.Active.InstrumentationKey = args[0];
         }

         log.Trace("This is an nLog Trace message");
         log.Debug("This is an nLog Debug message");
         log.Info("This is an nLog Info message");
         log.Warn("This is an nLog Warning message");
         log.Error("This is an nLog Error message");
         log.Fatal("This is an nLog Fatal message");

         TelemetryConfiguration.Active.TelemetryChannel.Flush();

			Console.WriteLine("Press <enter> to exit>");
			Console.ReadLine();
		}
	}
}

Code for my sample console application is here.

Azure Function Log4Net configuration Revisted

In a previous post I showed how I configured Apache Log4Net and Azure Application Insights to work with an Azure Function, this is the code updated to .Net Core V3.1.

With the different versions of the libraries involved (Early April 2020) this was what I found worked for me so YMMV.

Initially the logging to Application Insights wasn’t working even though it was configured in the ApplicationIngisghts.config file. After some experimentation I found setting the APPINSIGHTS_INSTRUMENTATIONKEY environment variable was the only way I could get it to work.

namespace ApplicationInsightsAzureFunctionLog4NetClient
{
	using System;
	using System.IO;
	using System.Reflection;
	using log4net;
	using log4net.Config;
	using Microsoft.ApplicationInsights;
	using Microsoft.ApplicationInsights.Extensibility;
	using Microsoft.Azure.WebJobs;

	public static class ApplicationInsightsTimer
	{
		[FunctionName("ApplicationInsightsTimerLog4Net")]
		public static void Run([TimerTrigger("0 */1 * * * *")]TimerInfo myTimer, ExecutionContext executionContext)
		{
         ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

         using (TelemetryConfiguration telemetryConfiguration = TelemetryConfiguration.CreateDefault())
         {
            TelemetryClient telemetryClient = new TelemetryClient(telemetryConfiguration);
 
            var logRepository = LogManager.GetRepository(Assembly.GetEntryAssembly());
            XmlConfigurator.Configure(logRepository, new FileInfo(Path.Combine(executionContext.FunctionAppDirectory, "log4net.config")));

            log.Debug("This is a Log4Net Debug message");
            log.Info("This is a Log4Net Info message");
            log.Warn("This is a Log4Net Warning message");
            log.Error("This is a Log4Net Error message");
            log.Fatal("This is a Log4Net Fatal message");

            telemetryClient.Flush();
         }
      }
   }
}

I did notice that there were a number of exceptions which warrant further investigation.

'func.exe' (CoreCLR: clrhost): Loaded 'C:\Users\BrynLewis\source\repos\AzureApplicationInsightsClients\ApplicationInsightsAzureFunctionLog4NetClient\bin\Debug\netcoreapp3.1\bin\log4net.dll'. 
Exception thrown: 'System.IO.FileNotFoundException' in System.Private.CoreLib.dll
Exception thrown: 'System.IO.FileNotFoundException' in System.Private.CoreLib.dll
Exception thrown: 'System.IO.FileNotFoundException' in System.Private.CoreLib.dll
Exception thrown: 'System.IO.FileNotFoundException' in System.Private.CoreLib.dll
Exception thrown: 'System.IO.FileNotFoundException' in System.Private.CoreLib.dll
Exception thrown: 'System.IO.FileNotFoundException' in System.Private.CoreLib.dll
'func.exe' (CoreCLR: clrhost): Loaded 'C:\Users\BrynLewis\AppData\Local\AzureFunctionsTools\Releases\2.47.1\cli_x64\System.Xml.XmlDocument.dll'. 
'func.exe' (CoreCLR: clrhost): Loaded 'C:\Users\BrynLewis\source\repos\AzureApplicationInsightsClients\ApplicationInsightsAzureFunctionLog4NetClient\bin\Debug\netcoreapp3.1\bin\Microsoft.ApplicationInsights.Log4NetAppender.dll'. 
'func.exe' (CoreCLR: clrhost): Loaded 'C:\Users\BrynLewis\AppData\Local\AzureFunctionsTools\Releases\2.47.1\cli_x64\System.Reflection.TypeExtensions.dll'. 
Application Insights Telemetry: {"name":"Microsoft.ApplicationInsights.64b1950b90bb46aaa36c26f5dce0cad3.Message","time":"2020-04-09T09:22:33.2274370Z","iKey":"1234567890123-1234-12345-123456789012","tags":{"ai.cloud.roleInstance":"DESKTOP-C9IPNQ1","ai.operation.id":"bc6c4d10cebd954c9d815ad06add2582","ai.operation.parentId":"|bc6c4d10cebd954c9d815ad06add2582.d8fa83b88b175348.","ai.operation.name":"ApplicationInsightsTimerLog4Net","ai.location.ip":"0.0.0.0","ai.internal.sdkVersion":"log4net:2.13.1-12554","ai.internal.nodeName":"DESKTOP-C9IPNQ1"},"data":{"baseType":"MessageData","baseData":{"ver":2,"message":"This is a Log4Net Info message","severityLevel":"Information","properties":{"Domain":"NOT AVAILABLE","InvocationId":"91063ef9-70d0-4318-a1e0-e49ade07c51b","ThreadName":"14","ClassName":"?","LogLevel":"Information","ProcessId":"15824","Category":"Function.ApplicationInsightsTimerLog4Net","MethodName":"?","Identity":"NOT AVAILABLE","FileName":"?","LoggerName":"ApplicationInsightsAzureFunctionLog4NetClient.ApplicationInsightsTimer","LineNumber":"?"}}}}

The latest code for my Azure Function Log4net to Applications Insights sample is available on here.

Apache Log4net .NET Core and Application Insights

In the previous post I revisited my sample .NET application that used Apache log4net and Azure Application Insights. This post updates the application to .NET Core V3.1.

I had to remove the ability to set the instrumentation key via the command line as I couldn’t get it to work.

I tried initialising the logger after loading the telemetry configuration, passing the InstrumentationKey in as a parameter of the TelemetryConfiguration constructor etc. and it made no difference.

The only other option that appeared to work was setting the instrumentation key via an Environment Variable called APPINSIGHTS_INSTRUMENTATIONKEY

   class Program
   {
      private static ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

      static void Main(string[] args)
      {
         using (TelemetryConfiguration telemetryConfiguration = TelemetryConfiguration.CreateDefault())
         {
            TelemetryClient telemetryClient = new TelemetryClient(telemetryConfiguration);

            var logRepository = LogManager.GetRepository(Assembly.GetEntryAssembly());
            XmlConfigurator.Configure(logRepository, new FileInfo(Path.Combine(Environment.CurrentDirectory, "log4net.config")));

            log.Debug("This is a Log4Net Debug message");
            log.Info("This is a Log4Net Info message");
            log.Warn("This is a Log4Net Warning message");
            log.Error("This is a Log4Net Error message");
            log.Fatal("This is a Log4Net Fatal message");

            telemetryClient.Flush();
         }

         Console.WriteLine("Press <enter> to exit");
         Console.ReadLine();
      }
   }

I updated the Log4Net setup to use the ManagedColoredConsoleAppender which required a couple of modifications to the Log4Net.config file. (Initially it was failing because I was using the non US spelling of log4net.Appender.ManagedColoredConsoleAppender)

 <appender name="ColoredConsoleAppender" type="log4net.Appender.ManagedColoredConsoleAppender">
      <mapping>
         <level value="ERROR" />
         <foreColor value="White" />
         <backColor value="Red" />
      </mapping>
      <mapping>
         <level value="DEBUG" />
         <backColor value="Green" />
      </mapping>
      <layout type="log4net.Layout.PatternLayout">
         <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
      </layout>
   </appender>

I did notice that after a several seconds while waiting for the enter key to be pressed there were a number of exceptions which warrants further investigation.

devMobile.Azure.ApplicationInsightsLog4NetCoreClient.Program: 2020-04-08 17:14:23,455 [1] FATAL devMobile.Azure.ApplicationInsightsLog4NetCoreClient.Program – This is a Log4Net Fatal message
‘ApplicationInsightsLog4NetCoreClient.exe’ (CoreCLR: clrhost): Loaded ‘C:\Program Files\dotnet\shared\Microsoft.NETCore.App\3.1.3\System.Security.Cryptography.Encoding.dll’.
Exception thrown: ‘System.Threading.Tasks.TaskCanceledException’ in System.Private.CoreLib.dll
Exception thrown: ‘System.Threading.Tasks.TaskCanceledException’ in System.Private.CoreLib.dll
Exception thrown: ‘System.Threading.Tasks.TaskCanceledException’ in System.Private.CoreLib.dll
Exception thrown: ‘System.Threading.Tasks.TaskCanceledException’ in System.Private.CoreLib.dll
Exception thrown: ‘System.Threading.Tasks.TaskCanceledException’ in System.Net.Http.dll
Exception thrown: ‘System.Threading.Tasks.TaskCanceledException’ in System.Private.CoreLib.dll
Exception thrown: ‘System.Threading.Tasks.TaskCanceledException’ in System.Private.CoreLib.dll
Exception thrown: ‘System.Threading.Tasks.TaskCanceledException’ in System.Private.CoreLib.dll
Exception thrown: ‘System.Threading.Tasks.TaskCanceledException’ in System.Net.Http.dll
Exception thrown: ‘System.Threading.Tasks.TaskCanceledException’ in System.Private.CoreLib.dll
Exception thrown: ‘System.Threading.Tasks.TaskCanceledException’ in System.Net.Http.dll
Exception thrown: ‘System.Threading.Tasks.TaskCanceledException’ in System.Private.CoreLib.dll
Exception thrown: ‘System.Threading.Tasks.TaskCanceledException’ in System.Private.CoreLib.dll
Exception thrown: ‘System.Threading.Tasks.TaskCanceledException’ in System.Private.CoreLib.dll
The program ‘[13920] ApplicationInsightsLog4NetCoreClient.exe’ has exited with code 0 (0x0).
The program ‘[13920] ApplicationInsightsLog4NetCoreClient.exe: Program Trace’ has exited with code 0 (0x0).

A sample project is available here.

“Don’t forget to flush” .Net Core Application Insights

This post updates a previous post “Don’t forget to flush Application insights Revisited” for .Net Core 3.X and shows the small change required by the deprecation of on of the TelemetryClient constructor overloads.

warning CS0618: ‘TelemetryClient.TelemetryClient()’ is obsolete: ‘We do not recommend using TelemetryConfiguration.Active on .NET Core. See https://github.com/microsoft/ApplicationInsights-dotnet/issues/1152 for more details’

   class Program
   {
      static void Main(string[] args)
      {
#if INSTRUMENTATION_KEY_TELEMETRY_CONFIGURATION
         if (args.Length != 1)
         {
            Console.WriteLine("Usage AzureApplicationInsightsClientConsole <instrumentationKey>");
            return;
         }

         TelemetryConfiguration telemetryConfiguration = new TelemetryConfiguration(args[0]);
         TelemetryClient telemetryClient = new TelemetryClient(telemetryConfiguration);
         telemetryClient.TrackTrace("INSTRUMENTATION_KEY_TELEMETRY_CONFIGURATION", SeverityLevel.Information);
#endif
#if INSTRUMENTATION_KEY_APPLICATION_INSIGHTS_CONFIG
         TelemetryConfiguration telemetryConfiguration = TelemetryConfiguration.CreateDefault();
         TelemetryClient telemetryClient = new TelemetryClient(telemetryConfiguration);
         telemetryClient.TrackTrace("INSTRUMENTATION_KEY_APPLICATION_INSIGHTS_CONFIG", SeverityLevel.Information);
#endif
         telemetryClient.Context.User.Id = Environment.UserName;
         telemetryClient.Context.Device.Id = Environment.MachineName;
         telemetryClient.Context.Operation.Name = "Test harness";

         telemetryClient.TrackTrace("This is a .Net Core AI API Verbose message", SeverityLevel.Verbose);
         telemetryClient.TrackTrace("This is a .Net Core AI API Information message", SeverityLevel.Information);
         telemetryClient.TrackTrace("This is a .Net Core AI API Warning message", SeverityLevel.Warning);
         telemetryClient.TrackTrace("This is a .Net Core AI API Error message", SeverityLevel.Error);
         telemetryClient.TrackTrace("This is a .Net Core AI API Critical message", SeverityLevel.Critical);

         telemetryClient.Flush();

         telemetryConfiguration.Dispose(); // In real-world use a using or similar approach to ensure cleaned up

         Console.WriteLine("Press <enter> to exit");
         Console.ReadLine();
      }
   }

A sample project is available here

Apache Log4net and Application Insights Revisited

In a previous post I showed how we configured a client’s application to use Apache log4net and Azure Application Insights.

I modified the code to allow the Instrumentation Key input via a command line parameter or from the ApplicationInsights.config file.

class Program
{
   private static ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

   static void Main(string[] args)
   {
      if (( args.Length != 0) && (args.Length != 1 ))
      {
         Console.WriteLine("Usage AzureApplicationInsightsClientConsole");
         Console.WriteLine("      AzureApplicationInsightsClientConsole <instrumentationKey>");
         return;
      }

      if (args.Length == 1)
      {
         TelemetryConfiguration.Active.InstrumentationKey = args[0];
      }

      log.Debug("This is a Log4Net Debug message");
      log.Info("This is a Log4Net Info message");
      log.Warn("This is a Log4Net Warning message");
      log.Error("This is an Log4Net Error message");
      log.Fatal("This is a Log4Net Fatal message");

      TelemetryConfiguration.Active.TelemetryChannel.Flush();

      Console.WriteLine("Press <enter> to exit>");
      Console.ReadLine();
   }
}

I updated the Log4Net setup to use the ManagedColoredConsoleAppender which required a couple of modifications to the Log4Net.config file. (I had to remove HighIntensity)

 <appender name="ColoredConsoleAppender" type="log4net.Appender.ManagedColoredConsoleAppender">
      <mapping>
         <level value="ERROR" />
         <foreColor value="White" />
         <backColor value="Red" />
      </mapping>
      <mapping>
         <level value="DEBUG" />
         <backColor value="Green" />
      </mapping>
      <layout type="log4net.Layout.PatternLayout">
         <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
      </layout>
   </appender>

A sample project is available here.

“Don’t forget to flush” Application Insights Revisited

This post revisits a previous post “Don’t forget to flush” Application insights and shows how to configure the instrumentation key in code or via the ApplicationInsights.config file.

 class Program
   {
      static void Main(string[] args)
      {
#if INSTRUMENTATION_KEY_TELEMETRY_CONFIGURATION
         if (args.Length != 1)
         {
            Console.WriteLine("Usage AzureApplicationInsightsClientConsole <instrumentationKey>");
            return;
         }

         TelemetryConfiguration telemetryConfiguration = new TelemetryConfiguration(args[0]);
         TelemetryClient telemetryClient = new TelemetryClient(telemetryConfiguration);
         telemetryClient.TrackTrace("INSTRUMENTATION_KEY_TELEMETRY_CONFIGURATION", SeverityLevel.Information);
#endif
#if INSTRUMENTATION_KEY_APPLICATION_INSIGHTS_CONFIG
         TelemetryClient telemetryClient = new TelemetryClient();
         telemetryClient.TrackTrace("INSTRUMENTATION_KEY_APPLICATION_INSIGHTS_CONFIG", SeverityLevel.Information);
#endif
         telemetryClient.TrackTrace("This is an AI API Verbose message", SeverityLevel.Verbose);
         telemetryClient.TrackTrace("This is an AI API Information message", SeverityLevel.Information);
         telemetryClient.TrackTrace("This is an AI API Warning message", SeverityLevel.Warning);
         telemetryClient.TrackTrace("This is an AI API Error message", SeverityLevel.Error);
         telemetryClient.TrackTrace("This is an AI API Critical message", SeverityLevel.Critical);

         telemetryClient.Flush();

         Console.WriteLine("Press <enter> to exit");
         Console.ReadLine();
      }

A sample project is available here