(FAQ) Frequently Asked Questions

What is native backend?

Native backend/runtime is GraalVM native-image compiled version of AWS Custom Runtime. Native runtime is entirely written in Clojure and upon hl:native:executable packed with the user code.

The output artifact of this operation is zip which can be deployed with any of the available deployment tools.

Can I use HL with CDK, Pulumi, Terraform?

Sure! HL doesn't stop you from using any of above deployment tools. All you need is the knowledge how to build deployable artifacts, that you can reference in your deployment descriptor.

Deployable artifact coordinate according to backend

• Clojure - > .holy-lambda/build/output.jar

  Build command

  bb hl:compile
  

• Native -> .holy-lambda/build/latest.zip

  Build command

  bb hl:compile && bb hl:native:executable
  

  Content of latest.zip

  • bootstrap - a script that executes the initializes the runtime and executes the binary
  • output - native compiled Clojure user code + Custom runtime
  • native-deps - dependencies of the application

• Babashka -> src (Application sources provided as is)

  Babashka backend is provided as a serverless layer which you have to deploy manually and reference it's ARN in deployment descriptor.

  1. Deploy the layer and get it's ARN.
  2. Reference src as the CodeUri of your application.
  3. Set runtime to provided and reference ARN of the layer in layers option.
  4. Additional Clojure deps should be packed to a layer. Clojure deps are stored at: .holy-lambda/bb-clj-deps.
  5. Additional babashka pods should be packed to a layer. Babashka pods are stored at .holy-lambda/pods.

Is HL runtime asynchronous?

Nope! Native, Babashka and Java runtimes are synchronous, but handlers can be asynchronous for convenience and return either:

 - `Channel<Map|String|ByteArray|nil>`
 - `Future<Map|String|ByteArray|nil>`
 - `Promise<Map|String|ByteArray|nil>`

Still though the runtime will wait for the result of asynchronous handler, before taking a new task to process. Scaling lambdas should be achieved via concurrency option. More info here