Lambda layers for shared code in AWS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Lambda layer in AWS?

A Lambda layer is a way to package and share code or libraries that multiple Lambda functions can use. It helps avoid repeating the same code in each function.

beginner

How do Lambda layers help with code management?

Lambda layers let you keep shared code in one place. When you update the layer, all functions using it get the update without changing each function separately.

intermediate

Can a Lambda function use multiple layers?

Yes, a Lambda function can use up to five layers at the same time. This allows combining different shared code packages.

intermediate

What is the maximum size of a Lambda layer?

Each Lambda layer can be up to 50 MB compressed (zipped) and 250 MB uncompressed when deployed.

intermediate

How do you update shared code in Lambda layers?

You create a new version of the layer with the updated code and then update your Lambda functions to use the new layer version.

What is the main benefit of using Lambda layers?

A To monitor Lambda function performance

B To increase the memory of a Lambda function

C To share common code across multiple Lambda functions

D To schedule Lambda functions automatically

Lambda layers allow sharing common code or libraries across multiple Lambda functions, reducing duplication.

How many layers can a single Lambda function use at once?

A 3

B 5

C 1

D 10

A Lambda function can use up to 5 layers simultaneously.

What must you do to apply updated shared code in a Lambda layer to your functions?

A Update the Lambda function code only

B Restart the Lambda service

C Delete the old layer

D Create a new layer version and update the function to use it

You create a new version of the layer with updated code and then update your Lambda functions to use this new version.

What is the maximum compressed size of a Lambda layer?

A 50 MB

B 10 MB

C 100 MB

D 250 MB

Each Lambda layer can be up to 50 MB compressed (zipped).

Which of the following is NOT a use case for Lambda layers?

A Storing environment variables

B Sharing utility libraries

C Including custom runtimes

D Sharing configuration files

Environment variables are set directly on Lambda functions, not stored in layers.

Explain how Lambda layers help reduce code duplication in AWS Lambda functions.

Think about how one package can be used by many functions instead of copying code.

Describe the steps to update shared code using Lambda layers and apply it to your Lambda functions.

Focus on versioning and function configuration.