Ensure AWS Lambda function is configured for function-level concurrent execution limit

Error: AWS Lambda function is not configured for function-level concurrent execution Limit

Bridgecrew Policy ID: BC_AWS_GENERAL_63
Checkov Check ID: CKV_AWS_115
Severity: LOW

AWS Lambda function is not configured for function-level concurrent execution Limit

Description

Adding concurrency to Lambda initializes that number of execution environments for multiple parallel requests at low latency. However, this could spike costs and open the door for abuse. Adding concurrency limits can prevent a rapid spike in usage and costs, while also increasing or lowering the default concurrency limit.

Fix - Buildtime

Terraform

  • Resource: aws_lambda_function
  • Argument: reserved_concurrent_executions
resource "aws_lambda_function" "example" {
   ...
+  reserved_concurrent_executions = 100
}

CloudFormation

  • Resources: AWS::Lambda::Function, AWS::Serverless::Function
  • Argument: Properties/ReservedConcurrentExecutions
Type: AWS::Lambda::Function
Properties: 
  ...
  ReservedConcurrentExecutions: 100
  ...