Function Versioning and Aliases

5 minutes 5 Questions

Function Versioning and Aliases are concepts in AWS Lambda that provide additional control over your application's deployment and rollback process. A version is an immutable snapshot of the Lambda function code and its configuration, including the runtime, memory size, and environment variables. Each version has a unique Amazon Resource Name (ARN) which remains unchanged throughout its lifecycle. An alias is a pointer to a specific version, which allows you to reference a Lambda function in your applications without updating them whenever the underlying function version changes. You can have multiple aliases pointing to different versions, which allows you to implement blue-green deployments, canary releases, and other advanced deployment strategies.

Function Versioning and Aliases in AWS Lambda: A comprehensive guide

As part of the AWS Solution Architect exam, understanding the concepts of Function Versioning and Aliases in AWS Lambda is imperative.

Why Function Versioning and Aliases are important: They offer the ability to seamlessly manage and invoke different versions of a function, enabling easy rollback, code testing, and staged deployment.

What are Function Versioning and Aliases: Function Versioning is a feature in AWS Lambda which allows you to manage different versions of a Lambda function. An Alias, on the other hand, is a pointer to a specific Lambda function version.

How they work: When you upload your code, AWS Lambda creates an initial version. For subsequent updates, you can create a new version which is an immutable snapshot of the code and configuration. Aliases help in routing traffic to different versions and can be accordingly updated to point to new versions.

Answering Exam Questions: Adhere to the basic principles of Aliases and Versions. Recognize that aliases allow you to direct incoming requests to different versions, and not all versions need to be available live; you can use versions to test and validate your code before updating the alias.

Exam Tips: Remember that a new version only gets created when you publish it - Lambda doesn't create versions automatically. Also, each version has its separate ARN. Comprehend that aliases can point to different versions and can be changed at any time. Understanding their organized, cohesive relationship can steer you towards the right answer in the exam.

Test mode:

Exam (Timed)

Practice (With explanations)

Start practice test

Question 1

You have a Lambda function that is responsible for generating reports, and you have created multiple versions of this function. Your team has asked you to create an alias for an older version of the function for debugging purposes, but also maintain the current alias for the latest version. Which of the following actions should you perform?

Delete the existing alias and create a new one for the older version. Create an additional alias pointing to the required older version of the function. Create a separate Lambda function for the older version. Update the existing alias to point to the older version.

Correct Answer: Create an additional alias pointing to the required older version of the function.

Aliases provide a way to manage multiple versions of a Lambda function with a single alias. You can create multiple aliases for different versions of the function. By creating an additional alias for the older version, you can maintain the existing alias for the latest version while allowing the debugging team to use the newly created alias.

Question 2

You have created a function with multiple versions and assigned aliases for the development, test, and production environments. How do you ensure that the development environment points to the latest version when publishing a new function version?

Delete the alias and recreate it to point to the latest version. Always use a wildcard ARN for the development environment. Update the development alias to point to the latest version. Use an event trigger with an automatic version update.

Correct Answer: Update the development alias to point to the latest version.

To ensure the development environment points to the latest version, after publishing a new version, update the development alias to point to this new version. This way, your development environment's alias always points to the latest changes made to the function.

Question 3

Your company is using AWS Lambda, and you have set up multiple function versions and aliases for staging, production, and development environments. However, you now need to restrict certain IAM principals to only invoke specific versions or aliases. What should you do?

Apply an IAM policy with a Condition statement restricting access to the specific versions or aliases. Create separate Lambda functions for each environment. Use security groups to restrict access. Update function-level access control for each version or alias separately.

Correct Answer: Apply an IAM policy with a Condition statement restricting access to the specific versions or aliases.

You can restrict access to specific versions or aliases of a Lambda function using IAM policies with a Condition statement that includes a qualifier, such as the alias or version resource. This ensures that only the specified IAM principals can access the specified versions or aliases in the policy.

Go Premium

AWS Certified Solutions Architect - Associate Preparation Package (2024)

More Function Versioning and Aliases questions

4 questions (total)