AWS: Lambda

Source Events

• AWS CLI.
• AWS API.
• AWS SDK.
• Triggers (via CloudWatch Events).

Scaling

• Lambda scales in parallel.
• Compute scales proportionately to memory allocation.
• Concurrency can be reserved for a specific funciton.
• You cannot reserve the last 100 available Lambda slots.

Billing

• Billed by memory allocated to the function.
• Billed per 100ms that the function is running.

Limitations

• The maximum execution time is 900 seconds. (Default is 180 seconds.)
• The default limit for concurrent Lambda functions is 1000.

Lambda and VPCs

• Lambda functions can access resources inside a VPC with configuration.

• When this happens, an ENI for the function is attached to the VPC.

• If a Lambda function needs Internet access while connected to a VPC, a NAT Gateway or Internet Gateway is required; data routes through the VPC.