I'm guessing this project preceded the open sourcing of https://github.com/aws/aws-lambda-java-libs, but now that it's available, what is the benefit of using this library instead?

Runtime only supports response payload up to 6MB. Using response streaming increases to 20MB.

/runtime/invocation/AwsRequestId/response – Propagates the Content-Type header from the runtime to send to the client. Lambda returns the response payload in chunks via HTTP/1.1 chunked transfer encoding. The response stream can be a maximum size of 20 MiB.

Any HTTP client that supports streaming answers may be used with Lambda Function URL.

As per title, is this project still maintained as there seems to have no commits since 2 years?

I figured that there is a open CVE in the latest published version 2.3.1 because of the used gson version, see https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-25647

Each invocation of the LambdaFunction calls the constructor of the provided Lambda handler.

This goes against the normal behaviour of the Java runtime, which only instantiates the Lambda handler class on the first invocation. The [custom runtime documentation](Initialization tasks) also mentions that "Initialize the function" should happen in the Initialization step and not when processing tasks.

Looking at the code, I think it is a matter of moving line 207 of LambdaRuntime outside the while(true) loop, but don't have enough context to be sure that does not break anything else.

I might find some time to experiment with this next week.

Publishing a Docker Image to hub.docker.com will allow to test lambda-runtime locally and not require deploying to AWS to verify.

aws-lambda-java-events allows converting of AWS JSON events to Java objects.

Adding support for:

• DynamodbEvent
• S3Event
• SQSEvent
• APIGatewayProxyRequestEvent

According to the custom runtime documentation, the processing task should

Propagate the tracing header – Get the X-Ray tracing header from the Lambda-Runtime-Trace-Id header in the API response. Set the _X_AMZN_TRACE_ID environment variable locally with the same value. The X-Ray SDK uses this value to connect trace data between services.

Without the _X_AMZN_TRACE_ID the X-Ray SDK cannot create subsegments which essentially means X-Ray cannot be used with Lambda functions running with this graalvm runtime.