AWS Lambda custom runtime with Java 18

An AWS Lambda custom runtime to enable Java 18 support on a minimalistic JRE, which only includes the Java modules required by the application. This is the example repository for the Build a custom Java runtime for AWS Lambda blog post.

1. Download the preferred Java version and take advantage of jdeps, jlink and Class Data sharing to create a minified and optimized Java runtime based on the application code (function.jar).
2. Create a bootstrap file with optimized starting instructions for the application.
3. Package the application code, the optimized Java runtime and the bootstrap file as a zip file.
4. Deploy the runtime, including the app, to AWS Lambda e.g. via the AWS Cloud Development Kit (CDK)

Getting started

1. Download or clone the repository.

2. install prerequisite software:

   1. Install AWS CDK
   2. Install Docker

3. Build and package the AWS Lambda function and create the AWS Lambda custom runtime using Docker:

./build.sh

4. Provision the AWS infrastructure (Amazon API Gateway, AWS Lambda and Amazon DynamoDB) using AWS CDK:

./provision-infrastructure.sh

The API Gateway endpoint URL is displayed in the output and saved in the file infrastructure/target/outputs.json. The contents are similar to:

{
  "LambdaCustomRuntimeMinimalJRE18InfrastructureStack": {
    "apiendpoint": "https://<API_ID>.execute-api.<AWS_REGION>.amazonaws.com/prod/"
  }
}

Using Artillery to test the changes

First, install prerequisites:

1. Install jq and Artillery Core
2. Run the following script from the projects root directory:

artillery run -t $(cat infrastructure/target/outputs.json | jq -r '.LambdaCustomRuntimeMinimalJRE18InfrastructureStack.apiendpoint') -v '{ "url": "/custom-runtime" }' infrastructure/loadtest.yml

Check results in Amazon CloudWatch Insights

1. Navigate to Amazon CloudWatch Logs Insights.
2. Select the log groups /aws/lambda/custom-runtime-java-18 from the drop-down list
3. Copy the following query and choose Run query:

 filter @type = "REPORT"
    | parse @log /\d+:\/aws\/lambda\/(?<function>.*)/
    | stats
    count(*) as invocations,
    pct(@duration+coalesce(@initDuration,0), 0) as p0,
    pct(@duration+coalesce(@initDuration,0), 25) as p25,
    pct(@duration+coalesce(@initDuration,0), 50) as p50,
    pct(@duration+coalesce(@initDuration,0), 75) as p75,
    pct(@duration+coalesce(@initDuration,0), 90) as p90,
    pct(@duration+coalesce(@initDuration,0), 95) as p95,
    pct(@duration+coalesce(@initDuration,0), 99) as p99,
    pct(@duration+coalesce(@initDuration,0), 100) as p100
    group by function, ispresent(@initDuration) as coldstart
    | sort by coldstart, function

You see results similar to:

For cold-starts only you will see results similar to:

Security

See CONTRIBUTING for more information.

License

This library is licensed under the MIT-0 License. See the LICENSE file.