Default Lambda Deployment | Overview.

Default Lambda Deployment - Overview.

Scope:

• Intro,
• Deployment Location,
• Invocation Flow,
• Scaling,
• Networking,
• Deployment Package,
• Lifecycle,
• Default Lambda vs Lambda@Edge.

Intro:

• The default deployment mechanism for an AWS Lambda function depends on the tools being used, but the most fundamental methods involve uploading a .zip file archive or a container image.
• When twtech create and deploy a function, AWS handles the provisioning of the underlying infrastructure, treating each invocation as potentially new and stateless.

1. Deployment Location

• Lambda functions are regional by default.
• twtech chooses an AWS region (e.g., us-east-2,) when creating the function.
• The function only runs in that region unless twtech replicate it to other regions.

2. Invocation Flow

• Clients (apps, APIs, AWS services) must send requests to that region to invoke the function.
• AWS provisions twtech function on-demand in the chosen region.
• If the function hasn’t been invoked for a while, a cold start occurs:
• AWS allocates a container.
• Loads twtech function code and runtime.
• Then executes twtech handler.

3. Scaling

• Automatic scaling — AWS runs multiple instances of twtech function in parallel if needed.
• Each execution environment handles one request at a time.
• There’s no extra configuration needed for scaling unless twtech wants reserved or provisioned concurrency.

4. Networking

• By default, Lambda functions can access the public internet (unless twtech attaches them to a VPC).
  By default, Lambda functions are created outside the VPC.
• They can also integrate with other AWS services in the same region without internet.

5. Deployment Package

• Code + dependencies are uploaded as:
• A ZIP file
• A container image (if using container-based Lambda)
• AWS stores it and deploys it to execution environments on-demand.

6. Lifecycle

Default (Regional) Lambda Lifecycle:

1. Creates Lambda in a region.
2. Deploys twtech code (publish version or use $LATEST).
3. On invocation, AWS:
• Allocates environment (cold start if needed)
• Runs handler function
4. Keeps environment warm for a short time for subsequent requests (warm starts).
5. Scales horizontally when traffic increases.

twtech biggest difference for: default Lambda vs Lambda@Edge,

• Default Lambda → lives in one AWS region.
• Lambda@Edge → replicated automatically to multiple global edge locations.