Cloud Practitioner Certification Exam

What is cloud computing?

• on-demand delivery of compute power; database storage, apps, and other IT resources

• pay-as you-go pricing

• provision EXACTLY the right configurations of resources needed

• instant access to necessary resources

Deployment Models of the Cloud

• Private Cloud: complete control, meets specific business needs, security for sensitive apps

• Public Cloud: six advantages of cloud computing; cloud resources and owned and operated by a third party cloud services delivered over the internet

• Hybrid Cloud: control over sensitive assets in private infrastructure

5 characteristics of cloud computing

• On-demand self service

  • users can provision resources and user them without human interaction from the service provider

• Broad network access

  • resources available over the network can be accessed by diverse client platforms

• Multi-tenancy and resource pooling

  • multiple customers can share the same infrastructure and applications with security and privacy

  • multiple customers are serviced from the same physical resources

• Rapid elasticity and Scalability

  • Automatically and quickly acquire and dispose 

  • Quickly and easily scale based on demand

• Measured service

  • usage is measured, users pay correctly for what they have used

6 Advantages of Cloud Computing

• trade CapEx for OpEx

  • pay on-demand: RENTING from AWS

  • reduced Total Cost of Ownership (TCO) & OpEx

• benefit from massive economies of scale

  • prices are reduced as AWS is more efficient due to large scale

• stop guessing capacity

  • scale based on actual measured usage

• increase speed and agility

  • no blockers to be efficient

• less $ spent on maintaining data center

• can go global in mins

Problems solved by the cloud

• flexibility, cost-effectiveness, scalability, elasticity, high-availability + fault tolerance, and agility

• Types of Cloud Computing 

• Infrastructure as a Service (IaaS)

  • provide building blocks for cloud IT (like legos)

  • provides networking, computers, data storage space

  • highest level of flexibility

  • easy parallel with traditional on-premises IT

  • examples 

    • amazon EC2, GCP, Azure, rackspace, digital ocean, linode

• Platform as a Service (PaaS)

  • removes the need for your organization to manage the underlying infrastructure 

  • focus on the deployment and management of your applications

  • examples

    • heroku, google app engine (GCP), windows azure (microsoft)

  • where you ONLY want to manage APPS and DATA

• Software as a Service (SaaS)

  • completed product that is run and managed by the service provider 

  • examples

    • many AWS services (rekognition for ML)

    • google apps (gmail), dropbox, zoom

Pricing of the Cloud

• AWS has 3 pricing fundamentals, following the pay-as-you-go pricing model

  • compute: pay for compute time

  • storage: pay for data stored in the cloud

  • data transfer OUT of the cloud: data transfer IN is free

• solves the expensive issue of traditional IT

AWS Cloud Use Cases

• enables you to build sophisticated, scalable apps

• applicable to a variety of industries

• applications are endless!!!!

AWS Global Infrastructure

• each region is connected through networks

• within each region, there are availability zones

• can leverage the infrastructure of AWS to make an app GLOBAL

• AWS has regions all around the world

  • names can be us-east-I, er-west-3…

  • region is a cluster of data centers

  • most AWS services are region-focused

How to choose an AWs region?

• if you need to launch a new app, which region should you deploy it at?

  • compliance

    • data governance and legal requirements; data never leaves a region without your explicit permission

  • proximity to customers

    • reduced latency

  • available services within a region

    • new services and features aren’t available in every region

  • pricing: varies between regions and is transparent in the service pricing page

AWS Availability Zones

• each region has availability zones (AZ)

  • one or more discrete data centers with redundant power, networking, and connectivity

  • they’re separate from each other, so that they’re isolated from disasters

  • connected with high bandwidth, ultra-low latency networking

AWS Points of Presence (edge locations)

• 400+ points of presence in 90+ cities across 40+ countries

Tour of AWS Console

• AWS has global services

  • Identity and Access Management (IAM)

  • Route 53 (DNS service)

  • CloudFront (Content Delivery Network)

  • WAF (Web Application Firewall)

• AWS has region-scoped services

  • Amazon EC2 (IaaS)

  • Elastic Beanstalk (PaaS)

  • Lambda (FaaS)

  • Rekognition (SaaS)

Shared Responsibility

• customer = responsibility for the security IN the cloud

• AWS = responsibility for the security OF the cloud

IAM Users & Groups

• IAM = Identity and Access Management, Global service

• Root account created by default, shouldn’t be used or shared

• Users are people within your organization, and can be grouped

• Groups only contain users, not other groups

• Users don’t have to belong to a group and users can belong to multiple groups

IAM: Permissions

• Users or Groups can be assigned JSON documents called policies

• these policies define the permissions of the users

• in AWS, you apply the least privilege principle: don’t give more permissions than a user needs

IAM Policies inheritance

• policies are separated in categories and users can inherit multiple depending on what groups they are part of

IAM Policies structure

• consists of 

  • lololol

IAM Password policy

• Strong passwords = higher security for your account

• in AWS, you can setup a password policy

  • prevents password re-use and requires users to change their passwords after some time

• Multi-Factor Authentication

  • users have access to your account and can possibly change configurations or delete resources in your AWS account

  • MFA = password you know + security device you 

  • device options

    • Virtual MFA device

      • google authenticator and authy (phone only)

    • Universal 2nd Factor (U2F) Security Key

      • yubikey (third party)

    • Hardware Key Fob MFA device

      • provided third party

    • Hardware Key Fob MFA device for AWS GovCloud (US)

      • SurePassID

IAM Roles for Services

• some AWS services will need to perform actions on your behalf

• to do so, we will assign permissions to AWS services with IAM Roles

• Common Roles

  • EC2 Instance Roles

  • Lambda Function Roles

  • Roles for CloudFormation

• IAM Credentials Report (account-level)

  • a report that lists all your acc’s users and the statuses of their various credentials

• IAM Access Adviser (user-level

  • shows the service permissions granted to a user and when those services were last accessed

  • you can use this information to revise your policies

IAM Guidelines + Best Practices

• one physical user = one AWS user

• use Access Keys for Programmatic Access (CLI/SDK)

• audit permissions of your account using IAM Credentials Report & IAM Access Advisers

• assign users to groups and assign permissions to groups

• don’t use root acc except for AWS acc setup

• NEVER share IAM users & Access Keys

Shared Responsibility Model for IAM

• AWS - responsible for the infrastructure

  • infrastructure (global network security)

  • configuration and vulnerability analysis

  • compliance validation

• You - HOW you use the infrastructure

  • users, groups, roles, policies management and monitoring

  • enable MFA 

  • rotating your keys often

  • using IAM tools to apply appropriate permissions

  • analyze access patterns and review permissions

IAM Summary

• Users: mapped to a physical user, has a password for AWS Console

• Groups: contains users only

• Policies: JSON doc that outlines permissions for users or groups

• Roles: for EC2 instances or AWS services

• Security: MFA + password policy

• AWS CLI: manage your AWS services using the command line

• AWS SDK: manage your AWS services using a programming language

• Access Keys: access AWS using the CLI or SDK

• Audit: IAM Credential Reports & IAM Access Advisor

EC2 - Elastic Compute Cloud

Basics

• EC2 is one of the most popular offerings

• IaaS

• Mainly consists of:

  • renting virtual machines (EC2)

  • storing data on virtual drives (EBS)

  • distributing load across machines (ELB)

  • scaling the services using an auto-scaling group (ASG)

EC2 Sizing and Configuration Options 

• Operating System: Linux, Windows, or Mac

• How much power and cores (CPU)

• how much random-access memory (RAM)

• How much storage space:

  • network-attached (EBS & EFS)

  • hardware (EC2 Instance Store)

• Network card: speed of the card, public IP address

• Firewall rules: security group

• Bootstrap script (configure at first launch): EC2 User Data

EC2 User Data

• it is possible to bootstrap our instances using an EC2 user data script

• bootstrapping means to launch commands when a machine starts

• script is only run once at the instance first start 

• EC2 user data is used to automate boot tasks such as:

  • installing updates

  • installing software

  • downloading common files from the internet

  • anything you can think of

• EC2 User Data Script runs with the root user

• use “http://” to launch an instance

EC2 Instance Types 

• you can use different types of EC2 instances for different use cases

• AWS has the following naming convention

  • m5.2xlarge

    • m: instance class

    • 5: generation (AWS improves them over time)

    • 2xlarge: size within the instance class

• General Purpose

  • great for diversity of workloads such as web servers or code repositories

  • balance between compute, memory, networking

  • examples: t2.micro, T4g, T3, T3a, M5, M5a, M4, A1

• Compute Optimized

  • great for compute-intensive tasks that require high performance processors

    • batch processing workloads

    • media transcoding

    • high performance web servers

    • high performance computing

    • scientific modeling and machine learning

    • dedicated game servers

  • examples: C6gn, C5, C5a, C5n, C4

• Memory Optimized

  • fast performance for workloads that process large datasets in memory

  • use cases

    • high performance, relational/non-relational databases

    • distributed web scale cache stores

    • in-memory databases optimized for BI (Business Intelligence)

    • Apps performing real-time processing of big unstructured data

  • examples: R6g, R5, R5a, R5b, R5n, R4, X1e, X1, High Memory, z1d

• Storage Optimized

  • great for storage-intensive tasks that require high, sequential read and write access to large data sets on local storage

  • use cases

    • high frequency online transaction processing (OLTP) systems

    • relational & NoSQL databases

    • cache for in-memory databases

    • data warehousing applications

    • distributed file systems

Security Groups & Classic Ports Overview

• security groups are the fundamental of network security in AWS

• they control how traffic is allowed in or out of our EC2 instances

• security groups only contain allow rules

• security groups rules can reference by IP or by security group

• security groups deeper dive

  • security groups are acting as a “firewall” on EC2 instances

  • they regulate:

    • access to ports

    • authorized IP ranges — IP v4 and IPv6

    • control of inbound network (from other to the instance)

    • control of outbound network (from instance to other)

• good to knows

  • can be attached to multiple instances

  • locked down to a region/VPC combination

  • does live “outside” the EC2 — if traffic is blocked the EC2 instance won’t see it

  • it’s good to maintain one separate security group for SSH access

  • if your application is not accessible (time out), then it’s a security group issue

  •  if your app gives a “connection refused” error, then it’s an app error or is not launched 

  • all inbound traffic is blocked and all outbound traffic is authorized by default

• referencing other security groups 

  • inbound rules allow only authorized security groups

• Classic Ports to know

  • 22 = SSH (Secure Shell) - log into a Linux instance

  • 21 = FTP (File Transfer Protocol) - upload files into a file share

  • 22 = SFTP (Secure File Transfer Protocol) - upload files using SSH

  • 80 = HTTP - access unsecured websites

  • 443 = HTTPS - access secured websites

  • 3389 = RDP (Remote Desktop Protocol) - log into a windows instance

SSH Overview (Mac, Linux)

• SSH is one of the most important functions.. it allows you to control a remote machine, all using the command line!

• use the public IPv4 

EC2 Instance Purchasing Options

• on-demand instances — short workload, predictable pricing,  pay by second

• reserved (1 & 3 years)

  • reserved instances — long workloads

  • convertible reserved instances — long workloads with flexible instances

• savings plans (1 & 3 years) — commitment to an amount of usage, long workload

• short instances — short workloads, cheap, can lose instances (less reliable)

• dedicated hosts — book an entire physical server, control instance placement

• dedicated instances — no other customers will share your hardware

• capacity reservations — reserve capacity in a specific AZ for any duration

• EC2 On Demand

  • pay what you use:

  • has the highest cost but upfront payment

  • no long-term commitment

• EC2 Reserved Instance

  • up to 72% discount compared to on-demand

  • reserve specific instance attributes (Instance Type, Region, Tenancy, OS)

  • Reservation Period — 1 year (+discount) or 3 years (+++discount)

  • Payment Options — No Upfront (+), Partial Upfront (++), All Upfront (+++)

  • Reserved Instance’s Scope — Regional or Zonal (reserve capacity in an AZ)

  • recommended for steady-state usage applications (e.g. database)

  • you can buy and sell in the Reserved Instance Marketplace

• Convertible Reserved Instance

  • can change the EC2 instance type, instance family, OS, scope, and tenancy

  • up to 66% discount

• EC2 Savings Plans

  • get a discount based on a long-term usage (up to 72% - same as RIs)

  • commit to a certain type of usage ($10/h for 1 or 3 years)

  • usage beyond EC2 Savings Plans is billed at the On-Demand price

  • locked to a specific instance family & AWS region

  • flexible across:

    • instance size, OS, and tenancy

• EC2 Spot Instances

  • discounts up to 90% compared to On-Demand

  • instances that you can “lose” at any point of time if your max price is less than the current spot price

  • the MOST cost-efficient instances in AWS

  • useful for workloads that are resilient to failure

    • data analysis, batch jobs, image processing, any distributed workloads, workloads with a flexible start and end time

  • NOT suitable for critical jobs or databases

• EC2 Dedicated Hosts

  • a physical server with EC2 instance capacity fully dedicated to your use

  • allows you to address compliance requirements and use your existing server-bound software licenses (per-socket, per-core, pe—VM software licenses)

  • purchasing options

    • on-demand - pay per second for active dedicated host

    • reserved - 1 or 3 years (no upfront, partial upfront, all upfront)

  • the most expensive option

  • useful for software that have complicated licensing model (BYOL) 

  • or for companies with strong regulatory or compliance needs

• EC2 Dedicated Instances

  • instances run on hardware that’s dedicated to you

  • may share hardware with other instances in same account

  • no control over instance placement (can move hardware after stop/start)

  • Dedicated Instances: you have your own instance on your own hardware

  • Dedicated Hardware: you get access to the physical server itself and it gives you visibility on the lower-level hardware

• EC2 Capacity Reservations

  • reserve on-demand instances capacity in a specific AZ for any duration

  • you always have access to EC2 capacity when you need it

  • no time commitment (create/cancel anytime), no billing discounts

  • combine with with regional reserved instances and savings plans to benefit from billing discounts

  • you’re charged at on-demand rate whether you run instances or not

  • suitable for short-term, uninterrupted workloads that needs to be in a specific AZ

• Which purchasing option is right for me?

  • on-demand: coming and staying in resort whenever we like, we pay the full price

  • reserved: like planning ahead and if we plan to stay for a long time, we may get a good discount

  • savings plans: pay a certain amount per hour for certain period and stay in any room type 

  • spot instances: the hotel allows people to bid for the empty rooms and the highest bidder keeps the rooms. you can get kicked out anytime

  • dedicated hosts: we book an entire building of the resort

  • capacity reservations: you book a room for a period with full price even if you don’t stay in it

IP Address Charges in AWS

• starting Feb 1st 2024, there is a charge for all public IPv4 created in your account

• $0.005 per hour of public IPv4 ($3.6 per month)

• for new accounts in AWS, you have a free tier for the EC2 service: 750 hours of public IPv4 per month for the first 12 months

• for all other services there is no free tier!!

Shared Responsibility Model for EC2

• AWS

  • infrastructure

  • isolation on physical hosts

  • replacing faulty hardware

  • compliance validation

• user 

  • security groups rules

  • operating system patches and updates

  • software and utilities installed on the EC2 instance

  • IAM roles assigned to EC2 & IAM user access management

  • data security on your instance

EC2 Summary

• EC2 instance: AMI (OS) + Instance Size (CPU + RAM) + Storage + security groups + EC2 User Data

• Security Groups: firewall attached to the EC2 instance

• EC2 User Data: script launched at the first start of an instance

• SSH: start a terminal into our EC2 instances (Port 22)

• EC2 Instance Role: link to IAM roles

• Purchasing Options: 

  • on-demand

  • spot 

  • reserved (standard + convertible)

  • dedicated host

  • dedicated instance

EBS Volume

• What is an EBS Volume?

  • a network drive (NOT a physical drive) you can attach to your instances while they run

    • uses the network to communicate the instance, which means there may be a bit of latency

    • can be detached from an EC2 instance and attached to another one quickly

  • it allows your instances to persist data, even after their termination

  • they can only be mounted to one instance at a time

  • they are bound to a specific availability zone

  • analogy: think of them as a “network USB stick”

• locked to an AZ

  • an EBS volume in us-east-1a cannot be attached to us-east-1b

  • to move a volume across, you need to snapshot it first

• have a provision capacity (size in GBs and IOPS)

  • you get billed for all the provisioned capacity

  • you can increase the capacity of the drive over time

• EBS — delete on termination attribute

  • controls the EBS behavior when an EC2 instance is being terminated

  • by default, any other attached EBS volume is not deleted (attribute disabled)

  • this can be controlled by the AWS console / AWS CLI

  • use case: preserve root volume when instance is terminated

EBS Snapshots

• make a backup of your EBS volume at a point in time

• not necessary to detach volume to do snapshot, but recommended

• can copy snapshots across AZ or region

• you can transfer an EBS to another AZ through a snapshot

EBS Snapshots Features

• EBS snapshot archive

  • move a snapshot to an “archive tier” that is 75% cheaper

  • takes within 24-72h for restoring the archive

  • good for no-rush restores

• Recycle Bin for EBS Snapshots

  • setup rules to retain deleted snapshots so you can recover them after an accidental deletion (1 day-1y)

AMI Overview

• AMI = Amazon Machine Image 

• AMI are a customization of an EC2 instance

  • you add your own software, configuration, OS, monitoring…

  • faster boot/configuration time because all your software is prepackaged

• AMI are built for a specific region (and can be copied across regions)

• you can launch EC2 instances from:

  • a public AMI: AWS provided

  • your own AMI: you make and maintain them yourself

  • an AWS marketplace AMI: an AMI someone else made (and potentially sells)

• AMI Process (from an EC2 instance)

  • start an EC2 instance and customize it

  • stop the instance (for data integrity)

  • build an AMI — this will also create EBS snapshots

  • launch instances from other AMIs

EC2 Image Builder 

• used to automate the creation of virtual machines or container images

• ⇒ automate the creation, maintain, validate, and test EC2 AMIs

EC2 Instance Store

• EBS Volumes are network drives with good but LIMITED performance

• if you need a high-performance hardware disk, use EC2 Instance Store

• better I/O performance

  • EC2 Instance Store lost their storage if they’re stopped (ephemeral)

  • good for buffer / cache / scratch data / temporary content

  • risk of data loss if hardware fails

• backups and replication are your responsibility

 EFS — Elastic File System

• managed NFS (network file system) that can be mounted on 100s of EC2

• EFS works with Linus EC2 instances in multi-AZ

• highly available, scalable, expensive, pay per use, no capacity planning

• EBS vs EFS

  • EBS are bound by specific AZs

  • EBS snapshot → another AZ

  • EFS drive — shared file system

• EFS Infrequent Access (EFS-IA)

  • storage class that is cost-optimized for files not accessed every day

  • up to 92% lower cost compared to EFS Standard

  • EFS will automatically move your files to EFS-IA based on the last time they were accessed

  • enable EFS-IA with lifecycle policy

  • e.g. move files that are not accessed for 60 days to EFS-IA

  • transparent to the apps accessing EFS

• Shared Responsibility Model for EC2 Storage

  • AWS

    • infrastructure

    • replication for data for EBS volumes & EFS drives

    • replacing faulty hardware

    • ensuring their employees cannot access your data

  • user

    • setting up backup/snapshot procedures

    • setting up data encryption

    • responsibility of any data on the drives 

    • understanding the risk of using EC2 Instance Store

Amazon FSx — overview

• launch 3rd party high-performance file systems on AWS 

• fully managed services

  • FSx for Lustre

    • a fully managed high-performance scalable file storage for High Performance Computing (HPC)

    • the name Lustre is derived from “Linux” and “cluster”

    • machine learning, analytics, video processing, financial modeling ….

    • scales up to 100s GBs, millions of IOPS, sub-ms latencies

  • FSx for Windows File Server

    • a fully managed, highly reliable, and scalable Windows native shared file system

    • built on Windows File Server

    • supports SMB protocol and Windows NTFS

    • integrated with Microsoft Active Directory

    • can be accessed from AWS or your on-premise infrastructure

EC2 Instance Storage Summary

• EBS Volume

  • network drives attached to one EC2 instance at a time

  • mapped to an availability zones

  • can use EBS Snapshots for backups / transferring EBS volumes across AZ

• AMI

  • create ready-to-use EC2 instances with our customization

• EC2 Image Builder: automatically build, test, and distribute AMIs

• EC2 Instance Store

  • high performance hardware disk attached to our EC2 instance

  • lost if our instance is stopped/terminated 

• EFS: network file system, can be attached to 100s of instances in a region

• EFS-IA: cost-optimized storage class for infrequent accessed files

• FSx for Windows: network file system for windows servers

• FSx for Lustre: high performance computing Linus file system

Elastic Load Balancing and Auto Scaling Groups

• Scalability and High Availability

  • scalability means that an app/system can handle greater loads by adapting

  • there are two kinds of scalability

    • vertical scalability

      • can increase the size of the instance

      • t2.micro → t2.large

      • very common for non dist systems such as database

      • there’s usually a limit to how much you can vertically scale (hardware limit)

    • horizontal scalability (high elasticity)

      • increasing the number of instances/systems for your app

      • implies distributed systems

      • very common for web apps/modern apps

      • easy thanks to cloud offerings like EC2

  • scalability is linked but different to high availability

  • high availability

    • running app/system in at least 2 AZs

    • usually goes hand in hand with horizontal scaling

    • goal of high availability is to survive a data center loss

  • High availability & scalability for EC2

    • vertical scaling: increase instance size (up/down)

    • horizontal scaling: increase number of instances (out/in) 

      • auto scaling group

      • load balancer

    • high availability: run instances for the same app across multi AZ

      • auto scaling group multi AZ

      • load balancer multi AZ

• Scalability vs. Elasticity (vs. Agility)

  • Scalability: ability to accommodate a larger load by making the hardware stronger (scale up) or by adding nodes (scale out)

  • Elasticity: once a system is scalable, elasticity means that there will be some “auto-scaling” so that the system can scale based on the load. This is “cloud-friendly”; pay-per-use, match demand, optimize costs

• Agility: (not related to scalability - distractor) new IT resources are only a click away, which means that you reduce the time to make those resources available to your developers from weeks to just minutes

What is Load Balancing?

• load balancers are servers that forward internet traffic to multiple servers (EC2 instances) downstream

• Why use a load balancer?

  • spread load across multiple downstream instances

  • expose a single point of access (DNS) to your application

  • seamlessly handle failures of downstream instances

  • do regular health checks to your instances

  • provide SSL termination (HTTPS) for your websites

  • high available across zones

  • ELB (Elastic Load Balancer) is a managed load balancer

    • AWS guarantees that it will be working

    • AWS takes care of upgrades, maintenance, high availability

    • AWS provides only a few configuration knobs

  • costs less to set up your own load balancer but it will be a lot more effort on your end (maintenance, integrations)

  • 4 kinds of load balancers offered by AWS

    • App load balancer (HTTP/HTTPS) - layer 7

      • HTTP / HTTPS / gRPC

      • HTTP Routing features 

      • Static DNS (URL)

    • Network load balancer (ultra high performance, allows for TCP) - layer 4

      • TCP / UDP protocols

      • High Performance: millions of request per seconds

      • Static IP

    • Gateway load balancer - layer 3

      • GENEVE protocol on IP Packets (layer 3)

      • Route Traffic to Firewalls that you manage on EC2 instances

      • Intrusion detection

• What’s an Auto Scaling Group?

  • irl, the load on your websites and app can change

  • in the cloud, you can create and get rid of servers very quickly

  • the goal of an auto scaling group (ACG) is to:

    • scale out (add EC2 instances) to match an increased load

    • scale in (remove EC2 instances) to match a decreased load

    • ensure we have a minimum and a maximum number of machines running 

    • automatically register new instances to a load balancer

    • replace unhealthy instances

  • cost savings: only run at an optimal capacity (principle of the cloud)

• Auto Scaling Groups — Scaling Strategies

  • Manual Scaling: update the size of an ASG manually

  • Dynamic Scaling: respond to changing demand

    • Simple/Step Scaling

      • when a cloud watch alarm is triggered (e.g. CPU>70%) then add 2 units

      • when a cloud watch alarm is triggered (e.g. CPU <30%) then remove 1

    • Target Tracking Scaling

      • e.g. I want the avg ASG CPU to stay at around 40%

    • Scheduled Scaling

      • anticipate a scaling based on known usage patterns

      • e.g. increase the min capacity to 10 at 5pm on Fridays

    • Predictive Scaling

      • uses ML to predict future traffic ahead of time, forecasting what will happen in the future

      • automatically provisions the right number of EC2 instances in advance

      • useful when your load has predictable time-based patterns

• ELB & ASG 

  • High availability vs. Scalability (vertical and horizontal) vs. Elasticity vs. Agility in the Cloud

  • Elastic Load Balancers (ELB)

    • distribute traffic across backend EC2 instances, can be multi-AZ 

    • supports health checks

    • 4 types: 

      • Classic (old)

      • Application (HTTP - L7)

      • Network (TCP — L4)

      • Gateway (L3)

    • Auto Scaling Groups (ASG)

      • implement elasticity for your application across multiple AZ

      • scale EC2 instances based on the demand on your system, replace unhealthy instances

      • integrated with the ELB

S3

• one of the building blocks of AWS

• “infinitely scaling” storage

• many websites use