DVA-C02 Deployment Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  aws lambda publish-version --function-name my-function

  Why it's wrong here

  The `aws lambda publish-version` command creates an immutable snapshot of the current Lambda function's code and configuration, assigning it a unique version number. While this makes the new version available for use, it does not automatically direct any invocation traffic to it. To deploy this new version and shift traffic, an alias must be explicitly updated to point to it, or traffic routing configured through an alias.

• ✗

  aws lambda create-function --function-name my-function --zip-file fileb://my-code.zip

  Why it's wrong here

  The `aws lambda create-function` command is used to provision an entirely new AWS Lambda function, requiring a unique name and an initial code package. This operation does not update an existing function's code or configuration, nor does it create a new version of an already deployed function. Deploying a new version specifically refers to updating an *existing* function, typically using `update-function-code` followed by `publish-version` or directly updating an alias.

• ✓

  aws lambda update-alias --function-name my-function --name prod --function-version 2 --routing-config AdditionalVersionWeights={"1":0.9}

  Why this is correct

  This command precisely implements a canary deployment strategy by updating the `prod` alias. It configures the alias to direct 10% of the invocation traffic (calculated as 1.0 minus the specified `AdditionalVersionWeights` for the older version, 0.9) to the newly specified `function-version 2`. The remaining 90% of traffic continues to serve `version 1`, allowing for gradual rollout and monitoring of the new version before a full cutover.

• ✗

  aws lambda invoke --function-name my-function --payload '{}'

  Why it's wrong here

  The `aws lambda invoke` command is solely used to execute a Lambda function on demand, passing a specific payload as input to trigger its execution. Its purpose is to test the function's runtime behavior or to programmatically trigger it, not to modify its code, configuration, or deployment strategy. This command plays no role in the deployment process of a new function version.