Serverless by Example: Building a Real-Time Chat System

Web Summit, Lisbon, November 9th, 2017

One of the great advantages of serverless development is the possibility to “chain” multiple functions and tools together. This session will show as an example how to build a scalable and highly available web chat for real-time communications.

Transcript

1. © 2017, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
   Danilo Poccia, Technical Evangelist
   danilop@amazon.com
   Serverless by Example:
   Building A Real-Time Chat System
   @danilop
   danilop
   

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2. “Where” is Serverless?
   

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3. Client Back End
   AWS
   Lambda
   

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4. CDN
   Client Back End Devices
   Sensors
   Actuators
   AWS
   Lambda
   Gateway
   

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5. AWS Greengrass
   

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6. Lambda Functions on a Raspberry Pi
   AWS
   Greengrass
   Lambda
   Function
   

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7. AWS Snowball Edge
   100TB + Greengrass Core (≃ EC2 m4.4xlarge instance)
   

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8. Snowball Edge Use Cases
   “Snowball Edge enables us to extend the
   innovative capabilities of HealthSuite, our cloud-
   enabled connected health ecosystem of devices,
   applications and digital tools supported by AWS,
   even when there is no network support.”
   Embedded Applications
   —Dale Wiggins,
   Business Leader, HealthSuite digital platform,
   Philips
   

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9. Snowball Edge Use Cases
   “With AWS Snowball Edge, we can now collect
   100 TB of data with no intermediate steps, and
   we can also analyze the images immediately
   using the onboard compute capabilities.”
   Remote Locations for data collection and analysis
   — Bob Cowen,
   Director of Hatfield Marine Research Center,
   Oregon State University
   

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10. AWS Lambda@Edge
    Customize content delivery while reducing load on the origin
    Events / Triggers
    Take serverless to your users
    

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11. Lambda@Edge Use Cases
    Demo build of a
    CloudFront+S3 distribution,
    using Lambda@Edge
    to secure its HTTP headers
    

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12. Lambda@Edge Use Cases
    These processes include applying
    transactional labels to purchases so
    Blockbuster can track customer activity, and
    providing personalized recommendations
    based on previous purchases.
    Blockbuster runs serverless compute
    processes across AWS Regions and
    Amazon CloudFront edge locations (using
    Lambda@Edge) without provisioning or
    managing servers.
    

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13. Let’s build a Web Chat…
    

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14. Web
    Browser
    

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15. Web
    Browser
    CloudFront
    Edge Location
    S3
    Bucket
    HTTPS
    Static Content
    (HTML, CSS, JS)
    

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16. Web
    Browser
    CloudFront
    Edge Location
    S3
    Bucket
    HTTPS
    Amazon
    Cognito
    Authentication
    (AWS Temporary
    Credentials)
    Static Content
    (HTML, CSS, JS)
    

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17. Web
    Browser
    CloudFront
    Edge Location
    S3
    Bucket
    Amazon
    API Gateway
    Lambda
    Function(s)
    DynamoDB
    Table(s)
    HTTPS
    Dynamic
    Content
    Database
    Access
    Execute
    Functions
    Amazon
    Cognito
    Authentication
    (AWS Temporary
    Credentials)
    Static Content
    (HTML, CSS, JS)
    

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18. Let’s make it more interactive…
    

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19. Web
    Browser
    CloudFront
    Edge Location
    S3
    Bucket
    Amazon
    API Gateway
    Lambda
    Function(s)
    DynamoDB
    Table(s)
    AWS IoT
    Topic(s)
    HTTPS
    Dynamic
    Content
    Database
    Access
    MQTT over
    Secure WebSockets
    (Publish, Subscribe)
    Execute
    Functions
    Amazon
    Cognito
    Authentication
    (AWS Temporary
    Credentials)
    Static Content
    (HTML, CSS, JS)
    

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20. Web
    Browser
    CloudFront
    Edge Location
    S3
    Bucket
    Amazon
    API Gateway
    Lambda
    Function(s)
    DynamoDB
    Table(s)
    AWS IoT
    Topic(s)
    AWS IoT
    Rule(s)
    HTTPS
    Dynamic
    Content
    Database
    Access
    MQTT over
    Secure WebSockets
    (Publish, Subscribe)
    Subscribe
    Republish
    Execute
    Functions
    Amazon
    Cognito
    Authentication
    (AWS Temporary
    Credentials)
    Static Content
    (HTML, CSS, JS)
    

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21. Web
    Browser
    CloudFront
    Edge Location
    S3
    Bucket
    Amazon
    API Gateway
    Lambda
    Function(s)
    DynamoDB
    Table(s)
    AWS IoT
    Topic(s)
    AWS IoT
    Rule(s)
    HTTPS
    Dynamic
    Content
    Database
    Access
    MQTT over
    Secure WebSockets
    (Publish, Subscribe)
    Subscribe
    Republish
    Execute
    Functions
    Execute
    Functions
    Amazon
    Cognito
    Authentication
    (AWS Temporary
    Credentials)
    Static Content
    (HTML, CSS, JS)
    Publish
    

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22. Web
    Browser
    CloudFront
    Edge Location
    S3
    Bucket
    Amazon
    API Gateway
    Lambda
    Function(s)
    DynamoDB
    Table(s)
    AWS IoT
    Topic(s)
    AWS IoT
    Rule(s)
    HTTPS
    Dynamic
    Content
    Database
    Access
    MQTT over
    Secure WebSockets
    (Publish, Subscribe)
    Subscribe
    Republish
    Execute
    Functions
    Write to
    DynamoDB
    Execute
    Functions
    Amazon
    Cognito
    Authentication
    (AWS Temporary
    Credentials)
    Static Content
    (HTML, CSS, JS)
    Publish
    

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23. Web
    Browser
    CloudFront
    Edge Location
    S3
    Bucket
    Amazon
    API Gateway
    Lambda
    Function(s)
    DynamoDB
    Table(s)
    AWS IoT
    Topic(s)
    AWS IoT
    Rule(s)
    Kinesis
    Stream(s)
    HTTPS
    Dynamic
    Content
    Database
    Access
    MQTT over
    Secure WebSockets
    (Publish, Subscribe)
    Subscribe
    Republish
    Execute
    Functions
    Streaming
    Data
    Write to
    DynamoDB
    Execute
    Functions
    Execute
    Functions
    (Micro-Batches)
    Amazon
    Cognito
    Authentication
    (AWS Temporary
    Credentials)
    Static Content
    (HTML, CSS, JS)
    Publish
    

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24. Web
    Browser
    CloudFront
    Edge Location
    S3
    Bucket
    Amazon
    API Gateway
    Lambda
    Function(s)
    DynamoDB
    Table(s)
    AWS IoT
    Topic(s)
    AWS IoT
    Rule(s)
    Kinesis
    Stream(s)
    HTTPS
    Dynamic
    Content
    Database
    Access
    MQTT over
    Secure WebSockets
    (Publish, Subscribe)
    Subscribe
    Republish
    Execute
    Functions
    Streaming
    Data
    Write to
    DynamoDB
    Execute
    Functions
    Execute
    Functions
    (Micro-Batches)
    Amazon
    Cognito
    Authentication
    (AWS Temporary
    Credentials)
    Static Content
    (HTML, CSS, JS)
    Publish
    

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25. What about Topics & Rules?
    

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26. Web
    Browser
    AWS IoT
    Topics
    chat/in/${iot:ClientId}
    chat/out
    chat/pub/${room}
    chat/stream
    $aws/events/#
    Each client has a secure “input” topic
    to receive content from the back end
    All client can publish on an “output” topic,
    they are recognizable by their clientId
    All client can subscribe and receive
    from “public” topics
    Another “output” topic
    optimized for high volumes
    AWS IoT
    Lifecycle Events
    

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27. Web
    Browser
    AWS IoT
    Topics
    AWS IoT
    Rules
    chat/in/${iot:ClientId}
    chat/out
    chat/pub/${room}
    chat/stream
    $aws/events/#
    Each client has a secure “input” topic
    to receive content from the back end
    All client can publish on an “output” topic,
    they are recognizable by their clientId
    All client can subscribe and receive
    from “public” topics
    Another “output” topic
    optimized for high volumes
    AWS IoT
    Lifecycle Events
    Lambda function
    to process important messages,
    such as a new client connection
    Republish rule to send messages
    to the corresponding room public topic
    Lambda function to process
    high volume dreaming data
    Kinesis Stream to manage
    high volume streaming data
    Lambda function
    to process AWS IoT Lifecycle Events
    Store all messages in a database,
    to be sent to the client on connection
    

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28. Web
    Browser
    AWS IoT
    Topics
    AWS IoT
    Rules
    chat/in/${iot:ClientId}
    chat/out
    chat/pub/${room}
    chat/stream
    $aws/events/#
    Each client has a secure “input” topic
    to receive content from the back end
    All client can publish on an “output” topic,
    they are recognizable by their clientId
    All client can subscribe and receive
    from “public” topics
    Another “output” topic
    optimized for high volumes
    AWS IoT
    Lifecycle Events
    Lambda function
    to process important messages,
    such as a new client connection
    Republish rule to send messages
    to the corresponding room public topic
    Lambda function to process
    high volume dreaming data
    Kinesis Stream to manage
    high volume streaming data
    Lambda function
    to process AWS IoT Lifecycle Events
    Store all messages in a database,
    to be sent to the client on connection
    You can use this topic
    to inject JavaScript code
    in the browser
    

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29. So how does the flow look like?
    

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37. Demo
    https://chat.danilop.net/websummit
    

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38. Code
    https://github.com/danilop/serverless-chat
    More Info
    http://docs.aws.amazon.com/iot/latest/developerguide/protocols.html
    http://docs.aws.amazon.com/iot/latest/developerguide/life-cycle-events.html
    http://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/DynamoDB/DocumentClient.html
    

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39. From Event-Driven Architectures…
    

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40. …To Functional Programming?
    

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41. Functional Programming
    Transforming Data
    Using Expressions (Functions)
    Without Side Effects
    Immutable Data
    Pure Functions
    Higher-Order Functions
    From “Research Topics in Functional Programming” ed. D. Turner, Addison-Wesley, 1990, pp 17–42.
    1
    Why
    Functional Programming
    Matters
    John Hughes
    The University, Glasgow
    Abstract
    As software becomes more and more complex, it is more and more
    important to structure it well. Well-structured software is easy to write
    and to debug, and provides a collection of modules that can be reused
    to reduce future programming costs. In this paper we show that two fea-
    tures of functional languages in particular, higher-order functions and lazy
    evaluation, can contribute significantly to modularity. As examples, we
    manipulate lists and trees, program several numerical algorithms, and im-
    plement the alpha-beta heuristic (an algorithm from Artificial Intelligence
    used in game-playing programs). We conclude that since modularity is the
    key to successful programming, functional programming o↵ers important
    advantages for software development.
    1 Introduction
    This paper is an attempt to demonstrate to the larger community of (non-
    functional) programmers the significance of functional programming, and also
    to help functional programmers exploit its advantages to the full by making it
    clear what those advantages are.
    Functional programming is so called because its fundamental operation is
    the application of functions to arguments. A main program itself is written as
    a function that receives the program’s input as its argument and delivers the
    program’s output as its result. Typically the main function is defined in terms of
    other functions, which in turn are defined in terms of still more functions, until
    at the bottom level the functions are language primitives. All of these functions
    are much like ordinary mathematical functions, and in this paper they will be
    1
    An earlier version of this paper appeared in the The Computer Journal, 32(2):98–107,
    April 1989. Copyright belongs to The British Computer Society, who grant permission to
    copy for educational purposes only without fee provided the copies are not made for direct
    commercial advantage and this BCS copyright notice appears.
    https://www.cs.kent.ac.uk/people/staff/dat/miranda/whyfp90.pdf
    

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42. Let’s build a “Tag Cloud” from Your Pictures
    images
    

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43. getLabels
    groupBy
    +
    renderHtml
    images
    Amazon
    Rekognition
    browser
    Event-Driven Architecture
    Let’s build a “Tag Cloud” from Your Pictures
    

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44. renderHtml(groupBy(getLabels([images])), htmlParams)
    Functional View
    Let’s build a “Tag Cloud” from Your Pictures
    

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45. renderHtml(groupBy(getLabels([images])), htmlParams)
    Functional View
    Let’s build a “Tag Cloud” from Your Pictures
    

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46. renderHtml(groupBy(getLabels([images])), htmlParams)
    Functional View
    Let’s build a “Tag Cloud” from Your Pictures
    

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47. renderHtml(groupBy(getLabels([images])), htmlParams)
    Functional View
    Let’s build a “Tag Cloud” from Your Pictures
    

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48. map(f, [x1, x2, …, xn]) = [f(x1), f(x2), …, f(xn)]
    Higher-Order
    Functions
    filter(f, [x1, x2, …, xn]) = [xi if f(xi) is true]
    count([a, b, a, c, a, b]) = {a: 3, b: 2, c: 1}
    

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49. renderHtml(groupBy(getLabels([images])), htmlParams)
    ⇩
    renderHtml(count(map(getLabel, [images]))), htmlParams)
    Reusable
    More
    reusable
    

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50. Lambda Functions + Step Functions
    Lambda
    Function
    Input
    State
    Machine
    Output
    translate
    create
    execute
    Tasks
    State passing (Immutable Data)
    Tasks are performed only if required (Lazy Evaluation)
    A Lambda Function dynamically creating a State Machine executing the logic
    

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51. Event-Driven Architectures
    +
    Functional Programming
    +
    Standard Serverless Library
    Happy to get your feedback on this!
    

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52. What is Serverless?
    “Build and run
    applications
    without thinking
    about servers”
    

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53. https://bit.ly/devworkshops
    

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54. © 2017, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
    Danilo Poccia, Technical Evangelist
    danilop@amazon.com
    Serverless by Example:
    Building A Real-Time Chat System
    @danilop
    danilop
    

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