Java on AWS Lambda: Differences and challenges

For more than 25 years, Java has played an essential role in building enterprise applications. The traditional approach of deploying more or less monolithic applications on application servers is completely challenged in the cloud, especially with Serverless and Lambda functions. During this presentation, we will see the main paradigm differences as well as the challenges of this new approach: with among others the invocation and execution model, the development model (what about the usual frameworks), how to package and deploy, cold starts and optimizations, use cases...

Transcript

1. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
   © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
   Java on AWS Lambda:
   Differences and challenges
   Jerome Van Der Linden
   Sr Solutions Architect Builder @AWS
   23/05/2023
   

   View Slide

2. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
   © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
   Difference #1: Scope of responsibility
   

   View Slide

3. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
   A standard Serverful Java / Spring Application
   Client
   Application Load
   Balancer
   Instances
   HTTP server
   Spring Framework
   Application code
   Spring Boot application
   Dispatcher Servlet
   Handler Mapping
   Handler Adapter
   Controller
   Service
   Repository
   You take care of
   + networking + security + autoscaling + multi-AZ + patching + upgrades + …
   

   View Slide

4. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
   No infrastructure provisioning,
   no management
   Automatic scaling
   Pay for value Highly available and secure
   What is serverless?
   

   View Slide

5. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
   AWS Lambda
   F U L L Y M A N A G E D S E R V E R L E S S C O M P U T E
   Auto Scaling group
   Availability Zone A Availability Zone B Availability Zone C
   Region
   Instances Instances Instances
   AWS Lambda
   ≈
   Load Balancer
   EC2 Instance
   FireCracker
   MicroVM
   FireCracker
   MicroVM
   FireCracker
   MicroVM
   FireCracker
   MicroVM
   

   View Slide

6. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
   AWS Lambda
   F U L L Y M A N A G E D S E R V E R L E S S C O M P U T E
   Auto Scaling group
   Availability Zone A Availability Zone B Availability Zone C
   Region
   Instances Instances Instances
   AWS Lambda
   ≈
   Load Balancer
   EC2 Instance
   FireCracker
   MicroVM
   Execution
   Environment
   Language
   Runtime
   Application
   code
   You take care of
   FireCracker
   MicroVM
   FireCracker
   MicroVM
   FireCracker
   MicroVM
   FireCracker
   MicroVM
   

   View Slide

7. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
   © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
   Difference #2: Execution model
   

   View Slide

8. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
   A standard Serverful Java / Spring Application
   Client
   Application Load
   Balancer
   Instances
   HTTP server
   Spring Framework
   Application code
   Spring Boot application
   Dispatcher Servlet
   Handler Mapping
   Handler Adapter
   Controller
   Service
   Repository
   Always running
   Always accepting requests
   

   View Slide

9. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
   AWS Lambda
   Auto Scaling group
   Availability Zone A Availability Zone B Availability Zone C
   Region
   Instances Instances Instances
   AWS Lambda
   ≈
   Load Balancer
   EC2 Instance
   FireCracker
   MicroVM
   Execution
   Environment
   Language
   Runtime
   Application
   code
   FireCracker
   MicroVM
   FireCracker
   MicroVM
   FireCracker
   MicroVM
   FireCracker
   MicroVM
   NOT always running
   Accept 1 request at a time
   

   View Slide

10. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    E X E C U T I O N E N V I R O N M E N T S
    Time
    1 Initialization Execution Env. #1
    

    View Slide

11. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    E X E C U T I O N E N V I R O N M E N T S
    Time
    1 Initialization Execution
    Execution environment
    is blocked or busy for this
    entire time
    Env. #1
    

    View Slide

12. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    E X E C U T I O N E N V I R O N M E N T S
    Time
    1 Initialization Execution
    2 Initialization Execution
    Env. #1
    Env. #2
    3 Initialization Execution Env. #3
    

    View Slide

13. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    E X E C U T I O N E N V I R O N M E N T S
    Time
    1 Initialization Execution
    2 Initialization Execution
    Env. #1
    Env. #2
    3 Initialization Execution Env. #3
    Execution
    4
    

    View Slide

14. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Difference #3: Invocation model
    

    View Slide

15. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    E V E N T - D R I V E N F U N C T I O N S
    Event source Services (anything)
    Database
    AWS Service
    3rd party service
    Function
    Changes in
    data state
    Changes in
    resource state
    Request to
    endpoints
    Node.js
    Python
    C#
    Go
    Ruby
    Runtime API
    8 / 11 / 17
    

    View Slide

16. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    E V E N T - D R I V E N F U N C T I O N S
    Event source Services(anything)
    Function
    com.amazonaws:aws-lambda-java-core:1.2.2
    com.amazonaws:aws-lambda-java-events:3.11.1
    software.amazon.awssdk:dynamodb:2.20.56
    software.amazon.awssdk:s3:2.20.56
    software.amazon.awssdk:*
    Or any Java library you’d like to use
    

    View Slide

17. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    A N A T O M Y O F A F U N C T I O N
    public class App implements RequestHandler{
    public Response handleRequest(final Event event, final Context context) {
    // do some stuff
    return response;
    }
    }
    • Handler: function that will be triggered for each event received
    • Event: the incoming event that triggered the function (in JSON format)
    • Context: informations about the function configuration and invocation
    • Your code, anything, …
    • Input type
    • Output type
    

    View Slide

18. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    C O M M O N U S E C A S E S
    Amazon
    API Gateway
    AWS Lambda
    AWS Lambda
    AWS AppSync
    APIs / microservices
    (REST / GraphQL)
    AWS
    Lambda
    AWS Step
    Functions
    Orchestration
    AWS Lambda
    AWS Config
    Operations/
    Remediation
    AWS Lambda
    Amazon SNS
    AWS Lambda
    AWS Lambda
    Amazon
    EventBridge
    Amazon SQS
    Event-driven
    architectures
    File processing
    Stream
    processing
    Data processing
    (transformation
    , cleansing, …)
    Analytics
    IoT backend
    …
    

    View Slide

19. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    C O M M O N U S E C A S E : H A N D L I N G H T T P / R E S T R E Q U E S T S
    Amazon
    API Gateway
    AWS Lambda
    public class App implements RequestHandler {
    public APIGatewayProxyResponseEvent handleRequest(final APIGatewayProxyRequestEvent input,
    final Context context) {
    String name = input.getQueryStringParameters().get("name");
    Map headers = new HashMap<>();
    headers.put("Content-Type", "application/json");
    APIGatewayProxyResponseEvent response = new APIGatewayProxyResponseEvent()
    .withHeaders(headers);
    try {
    String output = String.format("{ \"message\": \"hello %s\" }", name);
    return response
    .withStatusCode(200)
    .withBody(output);
    } catch (IOException e) {
    return response
    .withBody("{}")
    .withStatusCode(500);
    }
    }
    }
    

    View Slide

20. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Difference #4: Development model
    

    View Slide

21. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Single-purpose functions
    do “x”
    do “y”
    do “z”
    • Benefits:
    • Easier to debug, trace errors
    • Enforce least privilege, one role per function
    • Simpler to test
    • Favor reusability
    • Less surface area
    • Tips:
    • Use naming conventions and tags to enhance
    discoverability
    • Don’t go nano
    

    View Slide

22. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Testing
    • Unit / Integration tests with aws-lambda-java-tests
    @ParameterizedTest
    @Event(value = "sqs/sqs_event.json", type = SQSEvent.class)
    public void testInjectSQSEvent(SQSEvent event) {
    // test your handleRequest method with this event as parameter
    }
    • Local invocation with SAM:
    sam local invoke MyFunction --event local-event.json
    

    View Slide

23. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Difference #5: Deployment model
    

    View Slide

24. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    Supports either Zip or Jar format
    • Gradle: using Zip build type
    • Maven: using Shade plugin / Assembly
    plugin or Dependency plugin
    P A C K A G I N G
    https://docs.aws.amazon.com/lambda/latest/dg/java-package.html
    

    View Slide

25. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    Supports container images
    • AWS Images for Lambda
    (lambda/java)
    • Bring your own image (ex if
    you want Java 20)
    • Run and test images locally
    P A C K A G I N G
    $ docker build -t docker-image:test .
    $ docker run –p 9000:8080 docker-image:test
    $ curl –XPOST "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{}'
    https://docs.aws.amazon.com/lambda/latest/dg/java-image.html
    

    View Slide

26. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    • Using the AWS CLI: aws lambda create-function ...
    D E P L O Y M E N T
    

    View Slide

27. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    • Using the AWS CLI: aws lambda create-function ...
    • Using Infrastructure as code:
    § AWS SAM
    D E P L O Y M E N T
    https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/what-is-sam.html
    

    View Slide

28. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    • Using the AWS CLI
    • Using Infrastructure as code:
    § AWS SAM
    § AWS CDK
    D E P L O Y M E N T
    https://docs.aws.amazon.com/cdk/v2/guide/getting_started.html
    

    View Slide

29. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    • Using the AWS CLI
    • Using Infrastructure as code:
    § AWS SAM
    § AWS CDK
    § Terraform
    § …
    D E P L O Y M E N T
    https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/lambda_function
    

    View Slide

30. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Challenge #1: Lambda Limits
    

    View Slide

31. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Soft Limits
    C A N B E I N C R E A S E D
    Concurrency = (average requests per second) * (average request duration in seconds)
    è (average requests per second) = Concurrency / (average request duration in seconds)
    Ex for a function that takes 250ms: 1000 / 0.25 ≈ 4000 req / sec
    https://docs.aws.amazon.com/lambda/latest/dg/lambda-concurrency.html
    

    View Slide

32. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Hard limits
    AWS Step
    Functions
    Amazon S3
    Container
    image
    Amazon EFS (NFS)
    No GPU
    

    View Slide

33. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Challenge #2: Cold Starts
    

    View Slide

34. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    I N I T I A L I Z A T I O N O F T H E E X E C U T I O N E N V I R O N M E N T
    Cold start Warm start
    Time
    1 Initialization Execution Env. #1
    Execution
    4
    

    View Slide

35. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    I N I T I A L I Z A T I O N O F T H E E X E C U T I O N E N V I R O N M E N T
    Time
    1 Initialization Execution Env. #1
    Execution
    4
    Create Env Download code Start Runtime Initialize Function
    You can optimize this
    AWS optimizes this
    

    View Slide

36. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    I N I T I A L I Z A T I O N O F T H E E X E C U T I O N E N V I R O N M E N T
    Time
    1 Initialization Execution Env. #1
    Execution
    4
    Create Env Download code Start Runtime Initialize Function
    You can optimize this
    

    View Slide

37. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Reducing Cold Starts
    § Use AWS Java SDK v2 and use only the required dependencies (s3, dynamodb, …)
    § Remove unnecessary jar dependencies
    § Use lighweight dependencies (jackson-jr vs jackson, slf4j simple logger vs log4j, …)
    R E D U C E A S M U C H A S P O S S I B L E T H E S I Z E O F T H E P A C K A G E
    

    View Slide

38. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    I N I T I A L I Z A T I O N O F T H E E X E C U T I O N E N V I R O N M E N T
    Time
    1 Initialization Execution Env. #1
    Execution
    4
    Create Env Download code Start Runtime Initialize Function
    You can optimize this
    

    View Slide

39. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Reducing Cold Starts
    Use the AWS CRT HTTP Client
    • faster SDK startup time
    • smaller memory footprint
    • reduced latency time
    U S E T H E A W S C R T H T T P C L I E N T
    
    software.amazon.awssdk
    aws-crt-client
    
    S3AsyncClient
    .builder()
    .httpClientBuilder(
    AwsCrtAsyncHttpClient.builder().maxConcurrency(100))
    .build();
    https://aws.amazon.com/blogs/developer/announcing-availability-of-the-aws-crt-http-client-in-the-aws-sdk-for-java-2-x/
    

    View Slide

40. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Reducing Cold Starts
    § Objects that’s expected to be reused
    across multiple invocations should move
    its respective initialization code to either
    the static initializer or constructor.
    ⚠ Don’t store secrets that must not be reused
    § When using the AWS SDK, pre-configure
    specific items during client initialization.
    For example: region, the credentials
    provider, and endpoint.
    I N I T I A L I Z E B E F O R E T H E H A N D L E R
    

    View Slide

41. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Reducing Cold Starts
    § C1 is a lightweight & fast compiler (no profiling)
    § C2 is using the profiler to detect “hot” code and produce native
    code, optimised, but it’s heavier and slower
    – Also in the Lambda context (not always running), it’s not very useful
    § Set Tiered Compilation level to 1 with an environment variable
    U S E T I E R E D C O M P I L A T I O N
    JAVA_TOOL_OPTIONS=-XX:+TieredCompilation -XX:TieredStopAtLevel=1
    https://aws.amazon.com/blogs/compute/increasing-performance-of-java-aws-lambda-functions-using-tiered-compilation/
    

    View Slide

42. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Reducing Cold Starts
    • Avoid runtime dependency injection & reflection as much as possible (eg. Spring, Spring Boot)
    • Use compile-time dependency injection frameworks (eg. Dagger 2, Micronaut, Quarkus).
    A V O I D D I A N D R E F L E C T I O N
    https://github.com/aws-samples/serverless-java-frameworks-samples
    

    View Slide

43. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Reducing Cold Starts
    Compile your application ahead-of-time (AOT)
    and create Native Images with
    • https://www.graalvmonlambda.com/
    • Requires a custom Lambda Runtime
    • May not work for all Java applications
    B U I L D N A T I V E I M A G E S
    1
    10
    100
    1000
    10000
    100000
    1 2 3 4 5 6 7 8 9 10
    Iteration
    JVM Native image
    Same Lambda function with Quarkus
    invocation savings of more than 95%.
    https://aws.amazon.com/blogs/architecture/field-notes-optimize-your-java-application-for-aws-lambda-with-quarkus/
    

    View Slide

44. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Reducing Cold Starts
    Right size the memory with Lambda Power Tuning
    A D J U S T M E M O R Y ( A N D C P U )
    https://github.com/alexcasalboni/aws-lambda-power-tuning
    & use multi-threading
    

    View Slide

45. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    AWS Lambda
    I N I T I A L I Z A T I O N O F T H E E X E C U T I O N E N V I R O N M E N T
    Time
    1 Initialization Execution Env. #1
    Execution
    4
    Create Env Download code Start Runtime Initialize Function
    AWS optimizes this
    

    View Slide

46. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Reducing Cold Starts
    Use Provisioned Concurrency to warm-up ahead of time.
    Especially important if you’re expecting a big spike in traffic on a short amount of
    time.
    P R O V I S I O N E D C O N C U R R E N C Y
    https://docs.aws.amazon.com/lambda/latest/dg/provisioned-concurrency.html
    

    View Slide

47. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Reducing Cold Starts
    S N A P S T A R T
    Code
    execution
    Invoke
    Resume
    Resume
    Snapshot
    Post
    Snapshot
    Hook
    (optional)
    Pre
    Snapshot
    Hook
    (optional)
    Create
    Execution
    Environment
    Init during deployment
    Download
    Code
    Start
    Runtime
    Initialize
    Function
    Code
    Create
    Snapshot
    first request
    https://aws.amazon.com/blogs/compute/starting-up-faster-with-aws-lambda-snapstart/
    

    View Slide

48. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Going further…
    

    View Slide

49. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Want to try?
    W O R K S H O P J A V A O N A W S L A M B D A
    https://s12d.com/java-workshop
    

    View Slide

50. © 2022, Amazon Web Services, Inc. or its affiliates. All rights reserved.
    Thank you!
    Jerome Van Der Linden
    @jeromevdl
    

    View Slide