This is a simple serverless application built in Groovy. It consists of an Amazon API Gateway backed by four AWS Lambda functions and an Amazon DynamoDB table for storage.

• AWS CLI
• AWS SAM
• Java 11
• Groovy 4.0 (Read release notes for breaking changes)
• Gradle
• Artillery for load-testing the application

The AWS Lambda functions used in this application rely on tiered compilation. After following the above blog, you should be able to create Lambda Layer and use AWS_LAMBDA_EXEC_WRAPPER as an environment variable for the 4 AWS Lambda functions.

Deploy the demo to your AWS account using AWS SAM. Use serverless-groovy-demo as the app/stack name.

sam build && sam deploy --guided

SAM will create an output of the API Gateway endpoint URL for future use in our load tests. Make sure the app name used here matches with the STACK_NAME present under load-test/run-load-test.sh.

Artillery is used to make 200 requests / second for 2 minutes to our API endpoints. You can run this with the following command.

cd load-test
./run-load-test.sh

This is a demanding load test, to change the rate alter the arrivalRate value in load-test.yml.

Using this CloudWatch Logs Insights query you can analyse the latency of the requests made to the Lambda functions.

The query separates cold starts from other requests and then gives you p50, p90 and p99 percentiles.

filter @type="REPORT"
| fields greatest(@initDuration, 0) + @duration as duration, ispresent(@initDuration) as coldStart
| stats count(*) as count, pct(duration, 50) as p50, pct(duration, 90) as p90, pct(duration, 99) as p99, max(duration) as max by coldStart

X-Ray Tracing is available via Lambda Powertools for Java.

build.gradle dependency

plugins{
  id 'io.freefair.aspectj.post-compile-weaving' version '6.3.0'
}
...
dependencies {
  aspect 'software.amazon.lambda:powertools-tracing:1.10.2'
}

Example cold start trace

Example warm start trace

You can find implementations of this project in other languages here:

• 🦀 Rust
• ☕ Java (GraalVM)
• Kotlin
• 🏗️ TypeScript
• 🐿️ Go
• Micronaut, Quarkus, Springboot
• 🥅 .NET

See CONTRIBUTING for more information.

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