Lec 2: AWS Intro

Question 1

What is the core technique of cloud computing?

Answer 1

Virtualization

Question 2

What if the machine needs to be shut down for maintenance?

Answer 2

Virtual machine live migration: Alice can migrate the running VMs to different physical machines without interrupting any customers.

Question 3

What should Alice do?

Suppose Alice has a machine with 16 CPUs and 64 GB of memory. There are three customers:
Bob wants a machine with 8 CPUs and 32 GB of memory
Charlie wants a machine with 8 CPUs and 32 GB of memory
Daniel wants a machine with 4 CPUs and 8 GB of memory

Answer 3

Virtualization: Alice installs a virtual machine monitor (VMM) and provides each customer with a guest OS/virtual machine (VM) and the requested resources as vCPUs and guest physical memory.

Ex: Bob will be assigned with 8 vCPUs and 32GB of guest physical memory

Question 4

Can customers access other customers data?

Answer 4

No because of VM isolation: One customer cannot access data of another customer

Question 5

How is virtualization implemented?

Answer 5

-VMM (“Hypervisor”) has translation tables that map virtual (guest) memory to physical memory

Example:
VM 1 accesses memory cell #0; VMM maps this to memory cell #0
VM 2 accesses memory cell #0; VMM maps this to memory cell #300.

-VMs also time-share CPUs (a time-multiplexed manner)

Question 6

Time-multiplex does not work for memory. Why?

Answer 6

-Memory cannot be overlapped
-Other users are not supposed to access other memory spaces

Question 7

What if Alice serves more customers?

Answer 7

-Existing customers will be allocated less shares, thus performance will be affected

Question 8

Benefits of virtualization

Answer 8

Flexible to cloud providers, who
-can generate VMs with different resource capabilities
-can migrate VMs if necessary (e.g., for maintenance)
-can increase load by overcommitting resources

Secure to VMs
-One VM cannot access another without permission

Convenient to customers
- Complete control over the virtual ‘hardware’ (can install their own operating systems, applications, …)

But there might be performance impacts
-Load changes in one VM may affect the performance of another VM on the same physical machine (e.g., Bob is allowed to increase his vCPUs from 8 to 16.)

Question 9

Amazon: the pioneer (Timeline)

Answer 9

Jul 2002
Amazon Web Services launched

Mar 2006
Amazon S3 (Simple Storage Service) launched
-Proposed the ‘pay-per-use’ business model, which is now the standard in cloud computing

Aug 2006
Amazon EC2 (Elastic Compute Cloud) launched

Nov 2009
Microsoft Azure Beta launched
-Microsoft’s online services are gradually transitioning to Azure

Dec 2013
Google Compute Engine launched

Question 10

What services does a cloud provide? (3 common types)

Answer 10

Software as a service (SaaS)
SaaS delivers fully functional software on a subscription basis.

Platform as a service (PaaS)
PaaS provides a platform and pre-configured environment for users to develop their software.

Infrastructure as a service (IaaS)
IaaS offers basic computing resources such as virtual machines, storage, and network bandwidth.

Other XaaS: anything as a service (less common)
-Desktop as a service (DaaS)
-Network as a service (NaaS)

Question 11

What is SaaS? Give an example.

Answer 11

SaaS: Cloud provides an entire application

Email, Drive, Doc, Slides,…
Example: Google Workspace

Question 12

What is PaaS? Give an example.

Answer 12

PaaS: Cloud provides middleware

Common Language Runtime environment
Example: Heroku

Question 13

What is IaaS? Give an example.

Answer 13

IaaS: Cloud provides hardware resources

Virtual Machines, Virtual Memory, Virtual Disk,…
Examples: AWS Elastic Compute Cloud (EC2)

Question 14

Types of cloud in terms of target customers

Answer 14

Public cloud: open to general public.
Example: AWS, Microsoft Azure, Google Compute Engine

Community cloud: shared by multiple organizations with common interests and requirements.
Example: Healthcare Sectors

Private cloud: exclusively used by a single organization.
Example: Google’s internal datacenter

Question 15

What is XaaS cloud computing? Describe the different categories of XaaS cloud computing can provide and specific examples of each service.

Answer 15

Cloud computing offers a range of services, referred to as “XaaS,” which stands for “Anything as a Service.”

-Infrastructure as a Service that provides virtualized computing resources. An example is AWS EC2.

-Platform as a Service that provides a runtime environment for developers to build, deploy, and manage applications. An examples is Google App Engine or Heroku.

-Software as a Service that delivers fully functional software applications. An example is Microsoft 365 office or Google workplace.

Question 16

Examples of cloud services provided by AWS

Answer 16

Analytics
Application Integration
AWS Cost Management
Blockchain
Business Applications
Compute
Containers
Customer Enablement
Database
Developer Tools
End User Computing
Front-end Web & Mobile
Game Development
Internet of Things
Machine Learning
Management & Governance
Media Services
Migration & Transfer
Networking & Content Delivery
Quantum Technologies
Robotics
Satellite
Security, Identity, & Compliance
Storage

AWS: the leading cloud providing a wide range of services
The services satisfy different needs of customers:
-Allowing us to design, deploy, and manage applications on the cloud, so-called application architecture.
e.g., build a web application

Question 17

What is an application architecture?

Answer 17

It is the structural design and organization of a software application.

Question 18

What are the main types of application architecture?

Answer 18

Monolithic architecture
Client/Server architecture
Three-tier architecture
Cloud-based serverless architecture

Question 19

What is monolithic architecture? Give an example.

Answer 19

combines the frontend, backend, and database functionalities into a single application

e.g., wordpress: a content management system (CMS)

Question 20

What is Client/Server architecture? Give an example.

Answer 20

an application is split into two main components:
the client, which handles the user requests, and
the server, which handles the processing of requests and data storage.

e.g., gmail

Question 21

What is Three-tier architecture? Give an example.

Answer 21

a presentation tier (frontend),
application logic tier (backend), and
a database tier (backend)

e.g., Shopify: an e-commerce platform.

Question 22

What is Cloud-based serverless architecture? Give an example.

Answer 22

known as Function-as-a-Service, which is a cloud computing model where the cloud provider provisions, maintains and scales applications.

e.g., AWS Lambda

Question 23

Deploying a cloud application
When an application is ready, it can be deployed onto AWS via different services. What are these services?

Answer 23

Elastic Compute Cloud (EC2): an EC2 instance is a virtual machine that runs a Windows or Linux server. It is essentially running on Virtual Machine Monitor (VMM).

Elastic Container Service (ECS): a customized environment provided by an EC2 instance.

Question 24

Describe the main steps which you would take on AWS and the decisions that would need to be made to create, configure and launch an EC2 Instance.

Answer 24

Sign in to the AWS management console

Navigate to EC2 Dashboard and click “Launch instance”

Select/Create names and tags
–“Name and tags”: In this step, we add a tag for the instance, e.g., Key: Name, Value: 00000000-vm. We can click the “Add new tag” button to add multiple tags as needed.

Select AMI and Instance type
–“Application and OS Images (Amazon Machine Image)”: In this step, we select an AMI that suits our requirements.
–“Instance type”: In this step, we select an appropriate instance type. (t2.micro)

Select/Create Key pair for login
–“Key pair (login)”: In this step, we can select/create a key pair (SSH key) for secure access to our first instance.

Configure network settings and storage
–Create security group: a security group is a set of firewall rules that control the network traffic for our instance.
–“Configure storage”: In this step, we specify storage volume for our instance. By default, one EBS volume is attached to the instance. We can add more EBS volumes if needed.
—-EBS setting
–“Advanced details”
—-Instance purchasing options
—-IAM: a service that allows us to manage users, groups, and permissions to securely control access to AWS resources.

Review and launch

Question 25

Describe EBS and what features it offers

Answer 25

EBS is a ‘virtual disk’ and allocated in volumes. A volume ranges from 1GB to 1TB.
It provides block level storage volumes for EC2 instances. It is attached to any instance in the same Availability Zone. We pay for what we use with EBS.

Features:
Persistent Storage: EBS volumes persist independently from EC2 instances, indicating that when an instance is terminated, the data stored on the attached EBS volume CAN be retained.

High availability: EBS replicates volumes data across multiple physical servers within the same availability zone to prevent the loss of data from hardware failures.

Snapshots: allows users to create point-in-time snapshots of their volumes. These snapshots serve as backups and can be used to restore volumes to a previous state.

Elastic volumes : allows users to dynamically adapt their volumes when the needs of their applications change.

Question 26

What is an availability zone?

Answer 26

Availability zone: A region is further divided into multiple availability zones, which are identified by additional letters such as “us-west-2a” and “us-west-2b”.

Zones represent data centers in different physical locations within a region.

Each zone within a region is networked with low-latency connections

Question 27

What are the instance purchasing options available under advanced details when creating an EC2 instance?

Answer 27

On-Demand Instances
Savings Plans
Reserved Instances
Spot Instances
Dedicated Hosts
Dedicated Instances
Capacity Reservations

Question 28

What is the principle of least privilege?

Answer 28

A user only has those privileges which are essentially vital to perform their intended operations.

Question 29

Lab1: Configure AWS

Answer 29

aws configure

will output, need to enter every line
AWS Access Key ID [None]: AKIAIOSFODNN7EXAMPLE
AWS Secret Access Key [None]: wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY
Default region name [None]: ap-southeast-2
Default output format [None]: json

Question 30

Lab1:
Test the AWS environment

Test the Python environment

Answer 30

aws ec2 describe-regions –output table

python3
»> import boto3
»> ec2 = boto3.client(‘ec2’)
»> response = ec2.describe_regions()
»> print(response)

Question 31

Lab1: Install Python 3.8.x

Answer 31

sudo apt update
sudo apt -y upgrade

python3 -V

sudo apt install -y python3-pip

Python packages can be installed by: pip3 install package_name

Question 32

Lab1: Install awscli

Answer 32

sudo apt install awscli
pip3 install awscli –upgrade

OR sudo snap install aws-cli –classic

Question 33

Lab1: Install boto3

Answer 33

pip3 install boto3