Building Scalable IoT Applications

AWS IoT Platform

David Reines
VP of Technology
Object Partners, Inc.
david.reines@objectpartners.com
@dhreines

Introductions

Introduction

David Reines, VP of Technology at Object Partners
Eighteen years of industry experience
- Sixteen years at Object Partners
- Nine years telematics experience

Focus

Development, Architecture, Technology Leadership

Cloud Services, Distributed Systems, Microservices, Distributed Data Stores, Messaging Systems

Object Partners

Building and Delivering Custom Software Solutions
- Since 1996
- ~100 Full-time Consultants
Minneapolis, Omaha, Chicago
- Clients Nationwide

Modern Platforms

JVM
JavaScript
DevOps and Continuous Delivery
Real-time Data
Mobile
Solution Delivery

IoT @ Object Partners

Clients
- Telematics
- Home Automation
- And More…
Cloud IoT Platforms
- AWS IoT
- Exosite

IoT Blogs @ Object Partners

AWS IoT Platform

Managed platform for internet connected devices.

AWS IoT Provides

Fully Managed Service
Readily Available
Highly Scalable
Secure
Standard Protocol Support
Device Management Services
Simplified Integrations

Presentation Overview

Creating a Device
Understanding the Broker
Publishing Data via a Device
Capturing Data in the Cloud
Consuming Data via a Device
Managing Device State
Monitoring

Creating a Device (Thing)

Create a Thing Type

Up to three attributes
Searchable
Simplifies management
Not required

Create a Thing

Thing type and non-searchable attributes optional.

Create and Activate a Certificate

Download private key and certificate for device communication.

Create a Policy

Associate Certificate

To a device and policy.

Understanding the Broker

AWS IoT Message Broker

Pub/Sub message broker supporting MQTT, MQTT/WebSockets and HTTP (pub only).

MQTT

An ISO standard (ISO/IEC PRF 20922) publish-subscribe-based "lightweight" messaging protocol for use on top of the TCP/IP protocol. It is designed for connections with remote locations where a "small code footprint" is required or the network bandwidth is limited.

https://en.wikipedia.org/wiki/MQTT

MQTT Concepts

Clients connect with a "ClientId".
Clients publish messages to a "Topic".
Clients subscribe to "TopicFilters".

Topics and TopicFilters

// topics are divided into levels
abccompany/west/speed/SampleDevice
abccompany/east/temperature/AnotherDevice

// topic filters allow single (+) and multi-level (#) wildcards

// topic filter matching all west coast speed messages
abccompany/west/speed/+

// topic filter matching all abccompany messages in all regions
abccompany/#

// topic filter matching all speed messages
abccompany/+/speed/+

Quality of Service

QOS 0 (at most once)
QOS 1 (at least once)
QOS 2 (exactly once)
- not supported

Last Will and Testament (LWT)

Security

TLS Encryption
Authentication
- X.509 Certificate (MQTT, HTTPS)
- AWS IAM (HTTPS, WebSockets)
- AWS Cognito (HTTPS, WebSockets)
AWS Policy Based Authorization

Broker Policy Actions

iot:Connect, iot:Publish, iot:Subscribe, iot:Receive

Allow Connect

{
    "Effect": "Allow",
    "Action": [
        "iot:Connect"
    ],
    "Resource": [
        "arn:aws:iot:us-east-1:<aws-account>:client/SampleDevice"
    ]
}

Allow Receive

{
    "Effect": "Allow",
    "Action": [
        "iot:Receive"
    ],
    "Resource": [
        "arn:aws:iot:us-east-1:<aws-account>:topic/sample/SampleDevice"
    ]
}

Allow Publish

{
    "Effect": "Allow",
    "Action": [
        "iot:Publish"
    ],
    "Resource": [
        "arn:aws:iot:us-east-1:<aws-account>:topic/abccompany/west/speed/${iot:ClientId}"
    ]
}

MQTT 3.1.1 Deviations

QOS 2, cleanSession=false and more…

http://docs.aws.amazon.com/iot/latest/developerguide/protocols.html

cleanSession = false

Device Shadows
Application Level Acknowledgements
Lifecycle Events (Connect/Disconnect)

Publishing Data

via a Device

Device SDKs

Embedded C, JavaScript, Arduino Yún
Java, Python, iOS, Android

Java SDK MQTT Connection

CertificateUtils.KeyStorePasswordPair pair = CertificateUtils.getKeyStorePasswordPair(
    clientConfig.certificateFile, clientConfig.privateKeyFile
);

awsIotMqttClient = new AWSIotMqttClient(
    clientConfig.clientEndpoint, clientConfig.clientId, pair.keyStore, pair.keyPassword
);

awsIotMqttClient.connect();

Java SDK Publish

// sample speed publisher (see sample application)
awsIotMqttClient.publish("speed/" + clientId, AWSIotQos.QOS1, payload);

Capturing Data

Server-Side

Rules Engine

Provides SQL-like syntax for selecting messages and performing various actions.

Selecting Messages

SELECT *
  FROM 'speed/+'
 WHERE speed > 55

Available Actions

AWS ElasticSearch, Firehose, Kinesis, Lambda, SQS, S3, DynamoDB, Republish, CloudWatch, SNS

Rules Engine Demo

Send speeding messages to SQS.

Consuming Data

via a Device

Device Subscription Demo

public void subscribe() throws AWSIotException {

  log.info("Subscribing to sample topic.");
  AWSIotTopic topic = new AWSIotTopic("sample/" + clientId, AWSIotQos.QOS1) {

    @Override public void onMessage(AWSIotMessage message) {

      log.debug("Received message: {}", message.getStringPayload());
    }
  };
  awsIotMqttClient.subscribe(topic);
}

Device State Management

Device Shadows

Provides service for managing device state.

Example Device State

{
  "desired": {
    "minSpeed": 20
  },
  "reported": {
    "minSpeed": 20
  }
}

Device Shadow Demo

How’s this working?

Shadow Topics

$aws/things/thingName/shadow/update
$aws/things/thingName/shadow/update/accepted
$aws/things/thingName/shadow/update/documents (previous/current)
$aws/things/thingName/shadow/update/rejected
$aws/things/thingName/shadow/update/delta
$aws/things/thingName/shadow/get
$aws/things/thingName/shadow/get/accepted
$aws/things/thingName/shadow/get/rejected
$aws/things/thingName/shadow/delete
$aws/things/thingName/shadow/delete/accepted
$aws/things/thingName/shadow/delete/rejected

Device Helper Classes

// Java Helper
public class SampleShadowDevice extends AWSIotDevice {

  ....

  @AWSIotDeviceProperty
  private volatile int minSpeed;

  public int getMinSpeed() {
    return minSpeed;
  }

  public void setMinSpeed(int minSpeed) {
    this.minSpeed = minSpeed;
  }
}