Section - Serverless

Question 1

Exam Tips: AWS Lambda?

Answer 1

• One of the most common ways you’re going to see Lambda used is to “add” features to AWS.
• If you need to automatically remove entries from a security group, start and stop instances, or do anything else that isn’t built in, the answer is mostly likely going to be use Lambda
• Limitations:
  
  • 10 gig of ram
  • 15 minutes to run

Question 2

Current AWS Lambda characterics?

Answer 2

• Execution time 15 minutes (Hard limit)
• 1000 executions at a time
• Enviroment variables 4 KB
• Parameter limit on Syncronous process 64 MB
• Parameter limit on Asyncronous process 256 KB
• The first 1 million requests per month are free.
• 20 cents per 1 million requests

Question 3

AWS services that can invoke Lambda functions

Answer 3

Lambda Triggers:

• DynamoDB
• Kinesis
• SQS
• Application Load Balancer
• API Gateway
• Alexa
• CloudFront
• S3
• SNS
• SES
• CloudFormation
• CouldWatch
• CodeCommit
• CodePipeLine

https://docs.aws.amazon.com/lambda/latest/dg/lambda-services.html

Question 4

AWS Lambda Versioning?

Answer 4

• When you create a Lambda function, there is only one version $LATEST
• When you upload a new version of your code to Lambda, this version will become $LATEST
• You can create multiple versions of your function code and use aliases to reference the version you want to use as part of the ARN

Question 5

AWS Lambda concurrent executions limit?

Answer 5

Concurent Executions:

• Default is 1,000 concurrent executions per second per region (You can make a request to increase via AWS Support Center)
• TooManyRequestsException
• HTTP Status Code: 429
• Request throughput limit exceeded
• Reserved concurrency guarantees that a set number of executions which will always be available for your critical function, however this also acts as a limit.

Question 6

AWS Lambda connecting to a VPC?

Answer 6

Enabling Lambda to access VPC resources

• Lambda needs the following:
  
  • Private subnet ID
  • Security group ID (with required access)
  • Lambda uses this information to set up ENIs using an avialable IP address from your private subnet.

Question 7

What is ECS?

Answer 7

• Management of Containers at Scale
  
  • ECS can manage 1, 10 hundreds, or thousands of containers.
  • It will appropriatelly place the containers and keep them online.
• Elastic Load balancer Integration
  
  • Containers are appropriately registered with load balancers as they come online and go offline
• Role Integration
  
  • Containers can have individual roles attached to them making security a breeze.

Question 8

What is Elastic Kuberbetes Service (EKS)?

Answer 8

• AWS managed version of kubernetes.

Question 9

ECS vs EKS

Answer 9

• ECS
  
  • Proprietary AWS container management solution
  • Best used when you’all in on AWS and looking for something simple
  • Does not work on-prem
• EKS
  
  • AWS-Managed version of open source Kubernetes container management solution.
  • Best used when you’re not all in on AWS.
  • More work to configure and integrate with AWS.

Question 10

Exam Tips: ECS and EKS

Answer 10

• ECS is preferred
• Only consider EKS when running containers on-premises or open source.

Question 11

What is Fargate?

Answer 11

• AWS Fargate is a serverless compute engine for containers that works with both Amazon Elastic Container Service(ECS) and Amazon Elastic Kubernetes Service (EKS)
• Requires the use of ECS or EKS
• Linux-ony workloads

Question 12

EC2 vs Fargate?

Answer 12

• EC2
  
  • Yoiu are responsible for underlying operating system
  • EC2 pricing model
  • Long-running containers
  • Multiple containers share the same host
• Fargate
  
  • No operating system access
  • Pay based on resources allocated and time ran
  • short-running tasks (batch processing)
  • Isolated environments

Question 13

Fargate Vs Lambda

Answer 13

• Fargate
  
  • Select Fargate when you have more consistent workloads
  • Allows Dcoker use across the organization and a greater level of control by developers
  • can work on-prem as well
• Lambda
  
  • Great for unpredicatable or inconsistent workloads
  • perfect for applications that can be expressed as a single function.

Question 14

Exam Tips: Fargate

Answer 14

• When to use Lambda vs Fargate vs EC2
  
  • use lambda for light weight functions that can run very quickly that generally need to be integrated to AWS
  • Fargate whe nyou have containers which do not have to run all the time
  • EC2 when you have containers that run 24/7
  • Fargate is more expensive than EC2

Question 15

What is Amazon EventBridge?

Answer 15

• Amazon EventBridge (formerly known as CloudWatch Events) is a serverless event bus.
• it allows you to pass events from source to an endpoint.
• EventBridge holds together a serveless application and lambda functions. any API call that happens in AWS can alert a lambda function or a variety of different endpoints, that something has happened.