Java Lambda Archetype Broken (and out of date)

[luketn]

Describe the bug

When I tried to create the archetype for a Java lambda this morning, I got the error:

The desired archetype does not exist (software.amazon.awssdk:archetype-lambda:2.x)

In addition, the archetype hasn't been updated for several years.

It would be really useful to see an up to date version using Java 21 and your latest recommendations and best practices for a high-performing low latency cold start Java lambda.

Regression Issue

• Select this option if this issue appears to be a regression.

Expected Behavior

The archetype should generate a working lambda demonstrating the latest best practice for using the AWS SDK within a Java lambda.

I got to this page BTW after creating my own Java lambda using the default AWS SDK imports as documented and seeing absolutely abysmal performance. (4s to upload a 5 byte object to a bucket in the same region)

After profiling the lambda locally I saw that much of the time was initialising Apache Http client and TLS.

After switching to use the aws-crt implementation for http clients, this was radically improved:

S3Client.builder()
                        .region(Region.of(System.getenv(SdkSystemSetting.AWS_REGION.environmentVariable())))
                        .credentialsProvider(EnvironmentVariableCredentialsProvider.create())
                        .httpClient(AwsCrtHttpClient.builder().build())
                        .build();

Performance Improvement (Cold Start S3 Uploads):
Before (Apache client): Average 3,984 ms
After (CRT client): Average 2,806.5 ms
Improvement:
Absolute decrease: 1177.5 ms
Percentage improvement: ≈ 29.6% faster
Warm Starts: No significant change (remained around 22–25 ms).

I'm not sure if CRT is faster than Netty NIO with the special version mentioned here or not - I'd appreciate your advice.

Current Behavior

The archetype fails to create a project

Reproduction Steps

mvn archetype:generate \
    -DarchetypeGroupId=software.amazon.awssdk \
    -DarchetypeArtifactId=archetype-lambda \
    -DarchetypeVersion=2.x \
    -DgroupId=com.test \
    -DartifactId=sample-project \
    -Dservice=s3  \
    -DinteractiveMode=false

or

mvn archetype:generate \
  -DarchetypeGroupId=software.amazon.awssdk \
  -DarchetypeArtifactId=archetype-lambda \
  -DarchetypeVersion=2.x

Possible Solution

No response

Additional Information/Context

No response

AWS Java SDK version used

na

JDK version used

na

Operating System and version

Mac OS Sequoia 15.4.1

[debora-ito]

@luketn Hi Luke, thank you for reaching out.

software.amazon.awssdk:archetype-lambda works as a regular maven artifact, so you need to provide a specific version instead of 2.x, e.g.:

mvn archetype:generate \
    -DarchetypeGroupId=software.amazon.awssdk \
    -DarchetypeArtifactId=archetype-lambda \
    -DarchetypeVersion=2.31.45 \
    -DgroupId=com.test \
    -DartifactId=sample-project \
    -Dservice=s3  \
    -DinteractiveMode=false

archetype-lambda should work fine with JDK 21, let us know of the errors you are running into, if any.

As for recommendations: yes, using CRT HttpClient is one, and you can reduce the jar size by removing the other unused http clients; another recommendation is to initialize the service clients outside of the Lambda function handler, this way if the execution context is reused, the client initialization will be skipped.

You can read more details about these and other recommendations in our Developer Guide - Reduce SDK startup time for AWS Lambda

[luketn]

Thanks @debora-ito ! Can I suggest updating the readme to include the latest specific version, or if not a sentence telling you where to find the latest version to update the statement?
(probably should have thought of that!)

A couple of other errors that happened once I got past this:

1. Tests fail because the environment variable AWS_REGION is not set.

mvn test

->
[ERROR] AppTest.handleRequest_shouldReturnConstantValue:11 » NullPointer region must not be null.

You can get them running like:

AWS_REGION=eu-west-1 mvn package

Maybe the code in the DependencyFactory should have a fallback to a default region if there is no env var?

2. There are errors (both during tests and when deployed) because of some missing dependencies:
   [INFO] -------------------------------------------------------
   [INFO] Running com.test.AppTest
   SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
   SLF4J: Defaulting to no-operation (NOP) logger implementation
   SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
   [INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.299 s -- in com.test.AppTest

Could you recommend (and update the archetype) the most performant SL4J binding so that the AWS SDK doesn't have these logging errors?

As a suggestion it might also be good to include in the archetype POM some profiles for different archetecture targets. If you look at the CRT dependency, it includes binaries for every operating system resulting in a 26MB JAR. The profiles could either be specified on the command line or detect the current operating system.

[debora-ito]

Can I suggest updating the readme to include the latest specific version, or if not a sentence telling you where to find the latest version to update the statement?

Yes, we can do that. I also suggest checking our Developer Guide for up-to-date information, it is noted to replace 2.x with the latest version from maven central.

1. Tests fail because the environment variable AWS_REGION is not set.
   Maybe the code in the DependencyFactory should have a fallback to a default region if there is no env var?

So archetype-lambda is an utility that will create a template of a Java project for a Lambda function handler, for a quick and easy start using the Java SDK. The DependencyFactory generated by default will look for the AWS_REGION env variable, but you should replace that code with your own Lambda function logic.

Could you recommend (and update the archetype) the most performant SL4J binding so that the AWS SDK doesn't have these logging errors?

Yup, we got a feature request for that, tracking here: #5312. Feel free to thumbs up.

As a suggestion it might also be good to include in the archetype POM some profiles for different archetecture targets.

We have a feature request for this too, feel free to add a thumbs up: #5425

[luketn]

Thanks @debora-ito! I'll watch those other tickets and look for improved readme based on this one.