Serverless DevOps

Question 1

Give characteristic of serverless application

Answer 1

• No servers to provision or manage
• Automatically scales with usage
• Never pay for idle
• Highly available

Question 2

Name few service in AWS which are serverless

Answer 2

Any service which fullfil the characteristic of serverless is serverless service
- Lambda
- DynamoDB
- Api Gateway
- Step Functions
- Simple Queue Service

Question 3

What are advantage of serverless

Answer 3

• No Patching headache
• No scaling headache
• Pay for only usage

Question 4

What are disadvantage of serverless

Answer 4

• You can’t install any software like Webserver, Appserver
• For AWS Lambda, can only have a memory from 128 MB to 3 GB
• Your serverless function needs to complete in 1 sec to 15 mins. You can’t run long-running operations in a serverless function
• You can’t add hard disk, or deployment package size is limited

Question 5

What are use case for serverless

Answer 5

It shines in the event-driven architecture
- Say, you need to process something when the file is added to S3 or Kinesis
- It is suited when traffic is unpredictable, automation calling, pay as you go
- It use in a microservice architecture, it has integration with API Gateway, the Code is modular with software, easier to migrate to cloud-native, green fields apps

Question 6

On what parameters, Lambda cost is calculated?

Answer 6

• Number of time functions run in a month
• Memory used by the function
• Time is taken to execute the function

Question 7

What is serverless alternative to Microservice running on EC2

Answer 7

Lambda-API Gateway

Question 8

What is serverless alternative to Web server running on EC2

Answer 8

Website hosting using S3 + Lambda-API Gateway

Question 9

What is Serverless alternative to Databases on EC2?

Answer 9

Amazon RDS, Amazon Aurora

Question 10

What is Serverless alternative to Self Managed K8 cluster on EC2?

Answer 10

EKS, Fargate, ECS

Question 11

What is a Serverless alternative to ML on EC2

Answer 11

SageMaker

Question 12

There is a scenario where the client sends messages which need to be put in the SQS queue. What would you use, load balancer or API Gateway?

Answer 12

AWS Loadbalancer Target group can support Lambda, apart from Instance and IP. But, you need lambda or some code on EC2 to put to SQS
https://medium.com/nerd-for-tech/aws-lambda-behind-application-load-balancer-75f71413c9e6
AWS API Gateway can directly put message in SQS queue without the need of lambda or any code

Question 13

What is the difference between Equality-based and Set-Based label selector

Answer 13

Labels are used to filter out the kubernetes resource.Kubernetes has two selectors
Equality-based: Use =,==,!= and two Equality-based are used, it use as AND operator
Set-based: environment in (production, qa) OR operator

Question 14

What are the federated cluster in Kubernetes

Answer 14

Base cluster to manage multiple clusters.
E.g. Rancher, CrossPlane, etc.