Skip to content

mill5james/IoTEdgeMethodVsMessage

BranchesTags

Repository files navigation

IoTEdgeMethodVsMessage

Demonstrates sending messages and calling direct methods between modules using the Azure IoT Edge runtime

Producer

Implements direct method handler and an input message handler that just return the current time in UTC.

The latest image can be found in the Docker Hub at mill5james/producer

Consumer

Calls the direct method on the Producer module and records the timestamps for the method call.

Sends a message to the Producer module and waits for a message response on an input mesage handler, then records timestamps for the message exchange.

The latest image can be found in the Docker Hub at mill5james/consumer

Statistics from the Consumer

The statisitcs are collected by the Consumer module every minute in a background task. They capture:

  • The total number messages send and received and method calls
  • The latency for sending a message or invoking a method from the consumer to the producer (C->P)
  • The latency for sending a message or handling the method invocation from the producer to the consumer (P->C)
  • The total latency as seen at the consumer (Total)
  • A histogram of the total latency in 1 second bins

Example of the consumer module output every minute:

2019-06-19T19:32:16.4161739+00:00 - 2868 items in 1 minute
Messages         | Minimum    | Maximum    | Average    |
--------+--------+------------+------------+------------|
        |  C->P  |     1.0952 | 10019.3094 |    16.2191 |
    936 |  P->C  |     0.9817 |    51.9430 |     1.3836 |
        |  Total |     2.5858 | 10022.2115 |    17.6027 |
--------+--------+------------+------------+------------|
Count   | Millis | Percentage
--------+--------+-------------
    930 |  <1000 | ████████████
      0 |   1000 |
      0 |   2000 |
      2 |   3000 | █
      1 |   4000 | █
      0 |   5000 |
      0 |   6000 |
      0 |   7000 |
      0 |   8000 |
      0 |   9000 |
      3 | >10000 | █
--------+--------+-------------
Method           | Minimum    | Maximum    | Average    |
--------+--------+------------+------------+------------|
        |  C->P  |    14.1958 |  4504.8295 |    17.5319 |
   1932 |  P->C  |     0.8823 |   106.8569 |     1.5188 |
        |  Total |    15.5089 |  4508.3599 |    19.0508 |
--------+--------+------------+------------+------------|
Count   | Millis | Percentage
--------+--------+-------------
   1930 |  <1000 | ████████████
      0 |   1000 |
      0 |   2000 |
      1 |   3000 | █
      1 |   4000 | █
      0 |   5000 |
      0 |   6000 |
      0 |   7000 |
      0 |   8000 |
      0 |   9000 |
      0 | >10000 |
--------+--------+-------------

Build

By default the Dockerfile build will produce a image for Release targeting the stretch-slim .NET Code 2.2 image. Invoke the docker build command from the root of the repo.

docker build --file "Consumer/Dockerfile" --tag consumer:latest $PWD
docker build --file "Producer/Dockerfile" --tag producer:latest $PWD

Build for Debug

To build for debug, pass the build a build argumnet CONFIG=Debug which will build for Debug and include the debugger in the image

docker build --file "Consumer/Dockerfile" --tag consumer:debug --build-arg CONFIG=Debug $PWD
docker build --file "Producer/Dockerfile" --tag producer:debug --build-arg CONFIG=Debug $PWD

Target a different base image

To target another base image, pass the BASE_TAG build argumnet.

For example, to target alpine base image:

docker build --file "Consumer/Dockerfile" --tag consumer:alpine --build-arg BASE_TAG=alpine $PWD

For example, to target an ARM32 base image:

docker build --file "Consumer/Dockerfile" --tag consumer:arm32v7 --build-arg BASE_TAG=arm32v7 $PWD

IoT Edge Deployment

If you want to deploy just these modules to an IoT Edge for testing, you can simply download the deployment.json included in the repository.

If you want deploy these modules along other modules in your environment, the only deployment requirements are the message routes between the consumer and producer modules (assuming that your modules are named producer and consumer respectively.

   "routes": {
      "ConsumerToProducer": "FROM /messages/modules/consumer/outputs/GetTimeMessage INTO BrokeredEndpoint(\"/modules/producer/inputs/GetTimeMessage\")",
      "ProducerToConsumer": "FROM /messages/modules/producer/outputs/GetTimeMessage INTO BrokeredEndpoint(\"/modules/consumer/inputs/GetTimeMessage\")"
   },

Customize your deployment

You can disable invoking methods or sending messages from consumer module the deployment by passing false to the EnableMethod or EnableMessage environment variables. If you don't care about the histogram, you can set EnableHistogram to false.

   "consumer": {
      "settings": {
            "image": "mill5james/consumer:latest",
            "createOptions": "{}"
      },
      "type": "docker",
      "env": {
            "EnableMethod": {
               "value": "true"
            },
            "EnableMessage": {
               "value": "true"
            },
            "EnableHistogram": {
               "value": "true"
            }
      },
      "version": "1.0",
      "status": "running",
      "restartPolicy": "always"
   }

Known Issues

As of the iotedge 1.0.7.1 release, these are the known issues.

Exceptions seen in the Consumer module

Intermittently I see an IotHubCommunicationException with the message "The SSL connection could not be established, see inner exception." when calling ModuleClient.InvokeMethodAsync(...). The module recovers and subsequent calls succeed.

GetTimeMethod: Caught exception IotHubCommunicationException - The SSL connection could not be established, see inner exception.
Inner exception HttpRequestException - The SSL connection could not be established, see inner exception.
Inner exception HttpRequestException - The SSL connection could not be established, see inner exception.
   at Microsoft.Azure.Devices.Client.Transport.HttpClientHelper.ExecuteAsync(HttpMethod httpMethod, Uri requestUri, Func`3 modifyRequestMessageAsync, Func`2 isSuccessful, Func`3 processResponseMessageAsync, IDictionary`2 errorMappingOverrides, CancellationToken cancellationToken)
   at Microsoft.Azure.Devices.Client.Transport.HttpClientHelper.PostAsync[T1,T2](Uri requestUri, T1 entity, IDictionary`2 errorMappingOverrides, IDictionary`2 customHeaders, CancellationToken cancellationToken)
   at Microsoft.Azure.Devices.Client.ModuleClient.InvokeMethodAsync(Uri uri, MethodRequest methodRequest, CancellationToken cancellationToken)
   at IoTEdge.Consumer.GetTimeMethod(ModuleClient moduleClient, CancellationToken cancellationToken) in /src/Consumer/Consumer.cs:line 64

After running for some time, I see an IotHubCommunicationException with the message "Address already in use" when calling ModuleClient.InvokeMethodAsync(...). Once we receive this exception, the module never recovers and every subsequent call returns the same exception.

06/13/2019 17:54:17 - GetTimeMethod: Caught exception IotHubCommunicationException - Address already in use
Inner exception HttpRequestException - Address already in use
Inner exception HttpRequestException - Address already in use
   at Microsoft.Azure.Devices.Client.Transport.HttpClientHelper.ExecuteAsync(HttpMethod httpMethod, Uri requestUri, Func`3 modifyRequestMessageAsync, Func`2 isSuccessful, Func`3 processResponseMessageAsync, IDictionary`2 errorMappingOverrides, CancellationToken cancellationToken)
   at Microsoft.Azure.Devices.Client.Transport.HttpClientHelper.PostAsync[T1,T2](Uri requestUri, T1 entity, IDictionary`2 errorMappingOverrides, IDictionary`2 customHeaders, CancellationToken cancellationToken)
   at Microsoft.Azure.Devices.Client.ModuleClient.InvokeMethodAsync(Uri uri, MethodRequest methodRequest, CancellationToken cancellationToken)
   at IoTEdge.Consumer.GetTimeMethod(ModuleClient moduleClient, CancellationToken cancellationToken) in /src/Consumer/Consumer.cs:line 64

Exceptions seen in the Edge Hub

When only sending messages between modules, we will repeatedly see unacknowledged messages in the Edge Hub without any error in the producer or consumer. These will be followed by exceptions from the MQTT stack. I have no clue as to the periodicity of these exceptions.

2019-06-16 21:06:13.114 +00:00 [WRN] - Error sending messages to module jamesp-iotedge2/producer
System.TimeoutException: Message completion response not received
   at Microsoft.Azure.Devices.Edge.Hub.Core.Device.DeviceMessageHandler.SendMessageAsync(IMessage message, String input) in /home/vsts/work/1/s/edge-hub/src/Microsoft.Azure.Devices.Edge.Hub.Core/device/DeviceMessageHandler.cs:line 363
   at Microsoft.Azure.Devices.Edge.Hub.Core.Routing.ModuleEndpoint.ModuleMessageProcessor.ProcessAsync(ICollection`1 routingMessages, IDeviceProxy dp, CancellationToken token) in /home/vsts/work/1/s/edge-hub/src/Microsoft.Azure.Devices.Edge.Hub.Core/routing/ModuleEndpoint.cs:line 164
2019-06-16 21:06:14.139 +00:00 [WRN] - Closing connection for device: jamesp-iotedge2/consumer, scope: ExceptionCaught, DotNetty.Codecs.DecoderException: [MQTT-2.3.1-1]
   at DotNetty.Codecs.Mqtt.MqttDecoder.DecodePacketIdVariableHeader(IByteBuffer buffer, PacketWithId packet, Int32& remainingLength)
   at DotNetty.Codecs.Mqtt.MqttDecoder.DecodePublishPacket(IByteBuffer buffer, PublishPacket packet, Int32& remainingLength)
   at DotNetty.Codecs.Mqtt.MqttDecoder.DecodePacketInternal(IByteBuffer buffer, Int32 packetSignature, Int32& remainingLength, IChannelHandlerContext context)
   at DotNetty.Codecs.Mqtt.MqttDecoder.TryDecodePacket(IByteBuffer buffer, IChannelHandlerContext context, Packet& packet)
   at DotNetty.Codecs.Mqtt.MqttDecoder.Decode(IChannelHandlerContext context, IByteBuffer input, List`1 output)
   at DotNetty.Codecs.ReplayingDecoder`1.CallDecode(IChannelHandlerContext context, IByteBuffer input, List`1 output)
   at DotNetty.Codecs.ByteToMessageDecoder.ChannelRead(IChannelHandlerContext context, Object message)
   at DotNetty.Transport.Channels.AbstractChannelHandlerContext.InvokeChannelRead(Object msg), 6cfe9aea
2019-06-16 21:06:14.140 +00:00 [INF] - Disposing MessagingServiceClient for device Id jamesp-iotedge2/consumer because of exception - DotNetty.Codecs.DecoderException: [MQTT-2.3.1-1]
   at DotNetty.Codecs.Mqtt.MqttDecoder.DecodePacketIdVariableHeader(IByteBuffer buffer, PacketWithId packet, Int32& remainingLength)
   at DotNetty.Codecs.Mqtt.MqttDecoder.DecodePublishPacket(IByteBuffer buffer, PublishPacket packet, Int32& remainingLength)
   at DotNetty.Codecs.Mqtt.MqttDecoder.DecodePacketInternal(IByteBuffer buffer, Int32 packetSignature, Int32& remainingLength, IChannelHandlerContext context)
   at DotNetty.Codecs.Mqtt.MqttDecoder.TryDecodePacket(IByteBuffer buffer, IChannelHandlerContext context, Packet& packet)
   at DotNetty.Codecs.Mqtt.MqttDecoder.Decode(IChannelHandlerContext context, IByteBuffer input, List`1 output)
   at DotNetty.Codecs.ReplayingDecoder`1.CallDecode(IChannelHandlerContext context, IByteBuffer input, List`1 output)
   at DotNetty.Codecs.ByteToMessageDecoder.ChannelRead(IChannelHandlerContext context, Object message)
   at DotNetty.Transport.Channels.AbstractChannelHandlerContext.InvokeChannelRead(Object msg)

About

No description, website, or topics provided.

Resources

Readme
Activity

Stars

0 stars

Watchers

1 watching

Forks

0 forks
Report repository

Releases

No releases published

Packages

 
 
 

Contributors

Languages