Lambda

Question 1

What does AWS X-Ray do?

Answer 1

it allows you to scan Lambda architecture and debug issues with AWS Lambda

Question 2

Does AWS Lambda scale out automatically?

Answer 2

Yes

Question 3

Does AWS Lambda scale up automatically?

Answer 3

No

Question 4

Can an AWS Lambda function trigger another AWS Lambda Function?

Answer 4

Yes

Question 5

What does SAM stand for?

Answer 5

Serverless Application Model

Question 6

What is AWS SAM?

Answer 6

A superset of Cloudformation functionality that allows you to run serverless applications locally

Question 7

At a high level, what is Fargate?

Answer 7

Fargate is a serverless container engine

Question 8

What is the pricing structure for Fargate?

Answer 8

You specify and pay for resources per application

Question 9

In what instances would you use EC2 instances instead of Fargate?

Answer 9

• Strict compliance requirements
• Your use case requires broader customization (since you can’t actually get in to the Fargate instance)
• Your use case requires GPUs

Question 10

How does ECS benefit from ELB?

Answer 10

with ELB, you can distribute traffic evenly across tasks in your service

Question 11

What is the difference between EC2 Instance Roles and Task Roles?

Answer 11

• An EC2 Instance Role applies a policy to all tasks running in that EC2 instance
• A Task Role only applies to that task

So, Task Roles respect Least Priviledges better than EC2 instance Roles

Question 12

When configuring SQS as event source for AWS Lambda function, what is the maximum batch size supported by AWS SQS RecieveMessage API call?

Answer 12

10

Question 13

What Amazon CloudFront events can be used to trigger a Lambda Function?

Answer 13

• Viewer Request
• Viewer Response
• Origin Request
• Origin Response

_{(Source: https://github.cloud.capitalone.com/puggles/deposits-accounts-bankcard-pin/blob/develop/settings.xml#L9)}

Question 14

Suppose you change code and upload a new version of code to an AWS Lambda Function. What will happen to requests sent immediately after the code change?

Answer 14

For a brief period (usually less than one minute) requests might be served by either the old or new version

Question 15

What poll-based services are supported by AWS Lambda?

Answer 15

• Kinesis
• DynamoDB
• SQS

_{(Source: https://docs.aws.amazon.com/lambda/latest/dg/lambda-invocation.html?shortFooter=true%23streaming-event-source-mapping)}

Question 16

Are Lambda environment variables automatically encrypted?

Answer 16

They are encrypted when deployed, and decrypted when invoked (so your code can use them)

Question 17

What actions are required by Lambda Execution Role in order to write logs in CloudWatch?

Answer 17

• CreateLogGroup
• CreateLogStream
• PutLogEvents

Question 18

When a lambda is synchronously invoked and errors, what is returned?

Answer 18

A 200 status code

A FunctionError field in the response

Question 19

What is the pricing model for AWS Lambda?

Answer 19

• Requests (per million)
• Total Duration and Hardware (per GB-s)