Can we use both DynamoDb and VPC to an aws lambda?

Question

I am working on a AWS lambda in which i want to use DynamoDB and a VPC(Amazon elasticcache for redis). But I was getting time out error when trigger lambda

Answer 1

You either need to create a DyanmoDB VPC Endpoint in the VPC, or add a NAT Gateway to the VPC, and only deploy the Lambda function in subnets that have a route to the NAT Gateway.

Answer 2

Depending on the VPC configuration subnet/Security Group of your lambda,

If your lambda are in a public subnet, they can access to DynamoDB.

If your lambda is in a private subnet:

• If you want a secure internal way, you can pass with VPC endpoint
• Else if you want to pass with internet, you must have a NAT Gateway.

Check also the security groups/NACLS....

Answer 3

When you connect a function to a VPC, Lambda assigns your function to a Hyperplane ENI (elastic network interface) for each subnet in your function's VPC configuration.

Refer to link for more details - https://docs.aws.amazon.com/lambda/latest/dg/configuration-vpc.html

Answer 4

Consider taking 2 lambdas, one lambda to handle Dynamodb logic and another lambda is to communicate with VPC. And invoke the second lambda from the first lambda.