High Availability and Scalability: ELB and ASG

Question 1

A server that forwards traffic to multiple servers downstream

Answer 1

A load balancer

Question 2

Deprecated load balancer type that provides a fixed hostname and supports TCP (Layer 4) and HTTP/HTTPS (Layer 7) traffic

Answer 2

Classic Load Balancer

Question 3

True/False: Application Load Balancers are a great fit for micro services and container-based applications

Answer 3

True

Question 4

True/False: A Network Load Balancer can have multiple static IPs per AZ

Answer 4

False - Network Load Balancers have one static IP per AZ

Question 5

Load balancer type that is used to forward TCP & UDP traffic to your instances

Answer 5

Network Load Balancer

Question 6

True/False: Sticky sessions (session affinity) can be enabled for all load balancers

Answer 6

False - It can only be enabled for Classic and Application load balancers

Question 7

Feature that allows clients to be redirected to the same instance behind a load balancer on subsequent requests

Answer 7

Sticky Sessions

Question 8

What are the two types of cookies you can have when enabling sticky sessions on a load balancer?

Answer 8

Application-based cookies and duration-based cookies

Question 9

Feature that allows each load balancer instance to distribute traffic evenly across all registered instances in all AZs

Answer 9

Cross-Zone Load Balancing

Question 10

Cross-Zone Load Balancing is enabled by default for all load balancers

Answer 10

False - Enabled by default for an Application load balancer, but disabled by default for Network and Classic

Question 11

This type of certificate allows traffic between your clients and your load balancer to be encrypted in transit

Answer 11

SSL Certificate

Question 12

Newer protocol that allows you to load multiple SSL certificates onto one web server

Answer 12

Server Name Indication (SNI)

Question 13

True/False: Server Name Indication is supported by all Load Balancers

Answer 13

False - It is only supported by Application and Network load balancers, as well as CloudFront

Question 14

Which Load balancers use Server Name Indication (SNI) to support multiple listeners with multiple SSL certificates?

Answer 14

Application and Network Load Balancers

Question 15

Configurable time to complete ‘in-flight’ requests while an instance in de-registering from the ELB due to being unhealthy

Answer 15

Connection Draining / Deregistration Delay

Question 16

Scaling policy type that allows you to set a baseline for your ASG (i.e. “I want ASG CPU utilization to stay at 40%”)

Answer 16

Target Tracking Scaling

Question 17

Scaling policy that allows you to set actions to take based on specified CloudWatch alarms

Answer 17

Simple/Step Scaling

Question 18

Scaling policy that allows you to set scaling based on anticipated usage patterns

Answer 18

Scheduled Actions

Question 19

Scaling policy that uses ML to anticipate resource needs

Answer 19

Predictive Scaling

Question 20

True/False: Auto Scaling groups are configured using a Launch Template

Answer 20

True

Question 21

A collection of EC2 instances that are treated as a logical grouping for the purposes of automatic scaling and management

Answer 21

Auto Scaling Group

Question 22

If your website only sees traffic coming from private IPv4 addresses that belong to your Application Load Balancer, what should you do to get the IP address of clients connected to your website?

Answer 22

Modify your website’s backend to get the client IP address from the X-Forwarded-For header

Question 23

Which protocols does an Application Load Balancers support?

Answer 23

HTTP, HTTPS, and WebSocket

Question 24

ALBs can route traffic to different Target Groups based on what four traffic characteristics?

Answer 24

URL Path, Hostname, HTTP Headers, and Query Strings

Question 25

Network Load Balancers have one static IP address per AZ. What do Application Load Balancers and Classic Load Balancers have?

Answer 25

A static DNS name

Question 26

What are the three reserved cookie names for ELBs?

Answer 26

AWSALB, AWSALBAPP, and AWSALBTG

Question 27

A web application hosted on a fleet of EC2 instances managed by an Auto Scaling Group. You are exposing this application through an Application Load Balancer. Both the EC2 instances and the ALB are deployed on a VPC with the following CIDR 192.168.0.0/18. How do you configure the EC2 instances’ security group to ensure only the ALB can access them on port 80?

Answer 27

Add an Inbound Rule with port 80 and ALB’s Security Group as the source

Question 28

You have a website hosted in EC2 instances in an Auto Scaling Group fronted by an Application Load Balancer. Currently, the website is served over HTTP, and you have been tasked to configure it to use HTTPS. You have created a certificate in ACM and attached it to the Application Load Balancer. What you can do to force users to access the website using HTTPS instead of HTTP?

Answer 28

Configure the Application Load Balancer to redirect HTTP to HTTPS

Question 29

What type of load balancer offers Content-Based Routing?

Answer 29

Application Load Balancer

Question 30

True/False: You can assign an Elastic IP to an Application Load Balancer

Answer 30

False

Question 31

Feature used ensure that an Elastic Load Balancer stops sending requests to instances that are de-registering or unhealthy while keeping the existing connections open

Answer 31

Connection draining

Question 32

By default, cross-zone load balancing is _____ for Application Load balancer and _____ for Network Load Balancer

Answer 32

enabled; disabled