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

• AWS CLI
• AWS CDK
• Java 11
• Gradle
• Artillery for load-testing the application

Within the software folder is the Kotlin Gradle project. This single project contains all the code for all four Lambda functions.

To build the cod run:

gradle shadowJar

Deploy the demo to your AWS account using AWS CDK.

cdk deploy

CDK will create an output of the API Gateway endpoint URL for future use in our load tests.

Artillery is used to make 300 requests / second for 10 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

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

• 🦀 Rust
• ☕ Java (GraalVM)
• 🏗️ TypeScript
• 🐿️ Go
• 🥅 .NET

See CONTRIBUTING for more information.

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