HA Architecture

Question 1

How to make sure the customers IP is seen by the application?

Answer 1

X-Forwarded-For header needs be in place

Question 2

Why cross load balancing is disabled by default?

Answer 2

Probably to save costs. The cross zone balancing would allow the traffic to be evenly distributed among all the target instances even fi there is a different number of instances on the AZs

Question 3

What are the advanced features of ALB?

Answer 3

Path Pattern
Cross Zone Balancing
Sticky Session

Question 4

What are the scaling options for Auto Scaling?

Answer 4

Maintain current instance level: In case the instance is not health, a new one will be provisioned and added to the auto scaling group
Scale manually: specify the minimum, maximum and desired number of instance
Schedule: Scale automatically based as function of time and date
On demand: scale based on CPU utilization
Predictive: combination of EC2 Auto Scaling and AWS Auto Scaling to scale resources across multiple services

Question 5

What are the on-premise AWS services you can use?

Answer 5

Database Migration Service: Move database to/from AWS. Might have your DR environment in AWS and on-premise as the primary. It supports Oracle, MySQL, DynamoDB, etc with homogenous and heterogenous (different databases)

Server Migration Service: Incremental replication of on-premises servers into AWS. It can also be used as multi-site and DR strategies.

AWS Application Discovery Service: It is a virtual appliance on VMWare that will scan, map the dependencies and output the costs of infrastructure. The data will be available on the AWS Migration Hub to track the progress of the migration

VM Import/Export: From/to AWS VMs. It can be used for DR.

Download Amazon Linux 2 as an ISO: It works with all major virtualization providers