Alex Pshul & Moaid Hathot Senior Consultants @CodeValue, in their session from "Architecture Next 19"

1. A Serverless IoT Story
From Design to Production and Monitoring
Alex Pshul
Software Architect &
Consultant
@AlexPshul
alexp@codevalue.net
http://pshul.com
http://codevalue.net
Moaid Hathot
Senior Consultant
@MoaidHathot
moaidh@codevalue.net
http://www.moaid.codes
www.codevalue.net

2. Vision
 Manage a parking lot
 Know which parking spot is occupied
3

3. 4
Free Spots
32

4. Traditional Architecture
5
Devices communicators
WebApp
Service A
Load balancer
Service B Service C
Backend Services
Storage

5. How About Serverless?
6
WebApp

6. About Us
7
Alex Pshul
 Architect, Consultant and lecturer
 More than 8 years of hands on experience
 Talk to me about:
 Software Development
 Hardware and Gadgets
 Gaming
 Animals
Moaid Hathot
 Software engineer, consultant and code Jedi
 Software Craftsmanship advocate
 Clean Coder
 OzCode Evangelist

7. Serverless
Save time and money
10

8. Time & Money
 Pay per use
 Don’t worry about server management
 Quicker time to release
 Faster to deploy new functionality
 Don’t have to manage scaling and load balancing
 Focus on business logic instead of servers and boilerplate.
 Inherent Auto-Scalability
11

9. When to Serverless
 Logic can be disassembled into small modules
 Irregular Workloads
 Hard to predict load peaks
 Run closer to the user
12

10. When not to Serverless
 Performance is important
 A consistently high and predictable workload
 Long running tasks that can’t be split into sub-tasks or multiple cycles
 Complex computing with high memory/CPU requirements.
13

11. Migrating to Serverless
14
WebApp

12. Compute - FaaS
 FaaS – Function as a Service
 First mentioned by D. J. Wheeler in 1952- ‘The use of sub-routines in programmes’.
 Event-Driven serverless compute
 Examples:
 Azure Functions
 AWS Lambda
 Google Cloud Functions
15

13. FaaS – Azure Functions
 Trigger Oriented
 Input & Output Binding
 Dependency Injection
 Tackle Cold-Start performance hits by leaving host loaded
 Premium Plan
 AppService Plan
 Supports several frameworks and languages
 C#, JavaScript, Java, Python, F#, PowerShell & TypeScript
18

14. FaaS - Azure Functions
19
[FunctionName("EchoFunc")]
public static Task<IActionResult> EchoFunc(
[HttpTrigger(AuthorizationLevel.Anonymous, "get")]
HttpRequest request,
ILogger log)
{
string message = request.Query["message"];
//Do Something
var result = new OkObjectResult($"Message received: {message}");
return Task.FromResult((IActionResult) result);
}

15. FaaS – Azure Functions - Deployment
 Different ways to deploy your functions
 Visual Studio
 Using FTP
 Uploading a zip
 Continues deployment
 GitHub
 Dropbox
 Azure DevOps
 More…
21

16. Migrating to Serverless
23
WebApp

17. Events
 Process a high number of events per second
 Decouple communication between components
 Store and transform events
 Integrate with other services
24

18. Events – Azure EventHub
 Can receive and process millions of events per second
 Support Apache Kafka clients
 Integrate with other azure services
 Provide SDKs for several frameworks
 .Net, Node.js, Java, Python, Go, C, Apache Storm
 Enable capturing and storing events
 Partitioning
26

19. Events – Azure EventHub
27

20. Migrating to Serverless
30
WebApp

21. Communication
 Real-time
 Bi-directional
 Scale
 Secure
31

22. Communication – SignalR Service
 Fully managed
 Cross Platform
 Easily integrated with other Azure resources
 Such as Azure Functions
 Provides abstractions
 WebSockets, Long Polling or Server-sent events (SSE)
 Send message to all or to a subset of users
32

23. Integration
33
[FunctionName("UpdateUsers")]
public static Task OnDeviceUpdated(
[EventHubTrigger("device-updates", Connection = "EventHubConnectionAppSetting")] EventData myEventHubMessage,
[SignalR(HubName = "updates")]IAsyncCollector<SignalRMessage> signalRMessages,
ILogger log)
{
string message = Encoding.UTF8.GetString(myEventHubMessage.Body);
//Do something
return signalRMessages.AddAsync(new SignalRMessage
{
Target = "updateReceived",
Arguments = new[] { message }
});
}

24. Migrating to Serverless
36
WebApp

25. IoT
Avoid reinventing the wheel
37

26. Do Not Reinvent the Wheel
38
D2C
Messages
C2D
Messages
Devices
Management
Security
Message
Routing
Deployment

27. IoT Hub
 One of Microsoft`s PaaS solutions for building IoT solutions
 Provides the infrastructure for working with devices
 Most of the work is defining the devices and coding
 SDKs for various languages (.NET, Java, Node.js, Python, C, iOS)
 Exposes various endpoints
 Integration with other Azure services
39

28. IoT Hub - Tiers
 Each tier has 3 paid editions
 Each tier provides higher throughput
 Makes the service more expensive
 Basic tier
 Limited features
 Cheaper (compared with same standard tier edition)
 Standard tier
 All features are available
 More expensive (compared with same basic tier edition)
 Contains a free edition
 Standard Free edition
 1 free IoT Hub allowed per subscription
 Encourages PoC projects
 Same features as the Standard tier (Not same throughput)
40

29. Do Not Reinvent the Wheel
41
D2C
Messages
C2D
Messages
Devices
Management
Security
Message
Routing
Deployment

30. Device to Cloud Messages
 Send device telemetry to the cloud
 Using an SDK
 Send a message directly using a protocol
 MQTT (+ over WebSocket)
 AMQP (+ over WebSocket)
 HTTPS
 Uses a connection string to identify the device in the IoT Hub
 Stored by IoT Hub, up to 7 days
 Up to 256-KB messages
 Frequency depends on the selected IoT Hub edition
42

31. Device to Cloud Messages
43
static async Task Main(string[] args)
{
// Initialize the device client object
DeviceClient deviceClient =
DeviceClient.CreateFromConnectionString("Device_Connection_String");
// Create the message
var data = new { Temperature = 30, Humidity = 37 };
var messageString = JsonConvert.SerializeObject(data);
Message message = new Message(Encoding.ASCII.GetBytes(messageString));
// Send the message
await deviceClient.SendEventAsync(message);
}

32. Do Not Reinvent the Wheel
44
D2C
Messages
C2D
Messages
Devices
Management
Security
Message
Routing
Deployment
D2C
Messages

33. Cloud to Device Messages – Regular Messages
 Not awaited
 Stored in the device queue
 If queue is full (>50) - results in an error
 Can Reject or Abandon messages (unless MQTT)
 Can set feedback for each message
45

34. Cloud to Device Messages
46
static async Task Main(string[] args)
{
// Initialize the device client object
DeviceClient deviceClient =
DeviceClient.CreateFromConnectionString("Device_Connection_String");
// Read message
Message receivedMessage = await deviceClient.ReceiveAsync();
string messageString = Encoding.ASCII.GetString(receivedMessage.GetBytes());
Console.WriteLine($"Received message: {messageString}");
// Acknowledge completion
await deviceClient.CompleteAsync(receivedMessage);}
}
Device

35. Cloud to Device Messages
47
static async Task Main(string[] args)
{
// Initialize the service client object
ServiceClient serviceClient =
ServiceClient.CreateFromConnectionString("Service_Connection_String");
// Create the message
byte[] messageBytes = Encoding.ASCII.GetBytes("Cloud to device message.");
Message message = new Message(messageBytes);
// Send to a specific device
await serviceClient.SendAsync("myDeviceId", message);
}
Backend

36. Cloud to Device Messages – Direct Methods
 Initiate an action on the device
 Receive immediate response
 Response contains
 Status Code
 Payload
48

37. Cloud to Device Messages
49
static async Task Main(string[] args)
{
// Initialize the device client object
DeviceClient deviceClient = DeviceClient.CreateFromConnectionString("Device_Connection_String");
// Register Method
await deviceClient.SetMethodHandlerAsync("GetData", GetData, null);
}
private static Task<MethodResponse> GetData(MethodRequest request, object userContext)
{
string someData = "My Cool Response!";
byte[] dataBytes = Encoding.ASCII.GetBytes(someData);
MethodResponse response = new MethodResponse(dataBytes, 200);
return Task.FromResult(response);
}
Device

38. Cloud to Device Messages
50
static async Task Main(string[] args)
{
// Initialize the service client object
ServiceClient serviceClient =
ServiceClient.CreateFromConnectionString("Service_Connection_String");
// Create method object
var methodInvocation = new CloudToDeviceMethod("GetData");
methodInvocation.SetPayloadJson("10");
// Invoke the direct method asynchronously and get the response from the simulated device.
CloudToDeviceMethodResult response =
await serviceClient.InvokeDeviceMethodAsync("MyDotnetDevice", methodInvocation);
Console.WriteLine($"Status: {response.Status}. Payload: {response.GetPayloadAsJson()}");
}
Backend

39. Do Not Reinvent the Wheel
51
C2D
Messages
Devices
Management
Security
Message
Routing
Deployment
D2C
Messages
C2D
Messages

40. Devices Management – Twin Properties
 Devices can have states
 No feedback, unless subscribing to IoT Hub messages
 Desired Properties
 C2D
 Shouldn’t represent device state
 Reported Properties
 D2C
 Should reflect the current device state
52

41. Devices Management – Query Devices
 Devices can be queried
 Example: Get only the devices that were installed today
 Supports queries by twin properties as well
 Built in functions that allow more complex scenarios
 Simple example
 SELECT * FROM devices
 Returns all devices and their data
53

42. Devices Management – Device Provisioning Service
 Zero-Touch Provisioning
 Single IoT Hub
 Multitenancy
 Solution Isolation
 Geo-Sharding
 Much more scenarios…
54

43. Devices Management – Device Provisioning Service
55
Enrollment List
Device Provisioning ServiceDevice IoT Hub

44. Do Not Reinvent the Wheel
56
C2D
Messages
Devices
Management
Security
Message
Routing
Deployment
D2C
Messages
Devices
Management

45. Security
 Uses permissions to grant access to each IoT Hub endpoint
 RegistryRead
 RegistryReadWrite
 ServiceConnect
 DeviceConnect
 X.509 certificates
 Existing device certificate
 CA-signed certificate
 Self-generated and self-signed certificate
57

46. Security – Custom device authentication
 Use the identity registry to configure credentials
58

47. Do Not Reinvent the Wheel
59
C2D
Messages
Devices
Management
Security
Message
Routing
Deployment
D2C
Messages
Security

48. Message Routing
 Messages have a common format across protocols
 Routes send messages to different endpoints based on a query
 IoT Hub handles routing duplication
 Supports various endpoint types
 Built-in endpoint
 Azure Blob Storage
 Service Bus Queues and Service Bus Topics
 Event Hubs
60

49. Message Routing – Built-in endpoint & Event Hubs
 The Build-in endpoint is just like any other Event Hub endpoint
 Monitor build-in endpoint messages using Azure IoT Hub Toolkit extension
for VS/VS Code
 Stops receiving messages when another route is created
 Unless a route to the default endpoint is created explicitly
 Can add other Event Hubs for different routes
61

50. Message Routing – Azure Blob Storage
 Writes batches of data to the blob storage
 When size is reached
 When a certain time windows has passed
 Supports AVRO format only
 JSON format available as a preview
(Not supported in East US, West US and West Europe)
 A file is created for each batch of data
62

51. Message Routing – Service Bus Queues and Topics
 Session and Duplicate Detection must be disabled
 Endpoint will appear as unreachable if above is not met
63

52. Do Not Reinvent the Wheel
64
C2D
Messages
Devices
Management
Security
Message
Routing
Deployment
D2C
Messages
Message
Routing

53. Demo
IoT Hub
Device Deployment
65
*Show a picture of IoT Hub*

54. Monitoring
Full Solution
70

55. The Problem
 It is hard to debug remote resources
 Applications are built of small little modules
 Resources can be created and disposed of according to scale
 A monitoring approach is easier to achieve
 And is needed in any case
71

56. Monitor – Azure Functions
 Logging is your friend
 An ILogger object can be injected to your function
 Use Application Insights to view logs
72

57. Integration
73
[FunctionName("UpdateUsers")]
public static Task OnDeviceUpdated(
[EventHubTrigger("device-updates", Connection = "EventHubConnectionAppSetting")] EventData myEventHubMessage,
[SignalR(HubName = "updates")]IAsyncCollector<SignalRMessage> signalRMessages,
ILogger log)
{
log.LogDebug($"Body received with {myEventHubMessage.Body.Count} bytes");
string message = Encoding.UTF8.GetString(myEventHubMessage.Body);
log.LogInformation($"Message Extracted: {message}");
//Do something
return signalRMessages.AddAsync(new SignalRMessage
{
Target = "updateReceived",
Arguments = new[] { message }
});
}

58. Demo
End-to-end
scenario
77

59. Summary
78

60. Traditional Architecture
79
Devices communicators
WebApp
Service A
Load balancer
Service B Service C
Backend Services
Storage

61. Serverless Architecture
80
WebApp

62. Summary
 Serverless is not always the option
 But very useful
 Saves money and time
 IoT solutions are available as PaaS
 Don’t reinvent the wheel
 Debugging is not easy, but it is possible
 Monitoring is your friend
81

63. Ales Pshul
Software Architect & Consultant
@AlexPshul
alexp@codevalue.net
http://pshul.com
http://codevalue.net
Moaid Hathot
Senior Consultant
@MoaidHathot
moaidh@codevalue.net
http://www.moaid.codes
www.codevalue.net