Week 1: Intro to Cloud Computing

Question 1

How does virtualization work?

Answer 1

• Virtual machines are created using a hyper visor that managers the hardware resources
• Resources such as CPU, memory, storage, and network bandwidth are allocated to different VMs.
• Providers can “oversubscribe” CPU usage since not all VMs will require full processing power simultaneously​

Question 2

What is the anatomy of the platform of a web service?

Answer 2

User Interface: Users interact with the service via a browser or app.
DNS Resolution: Translates domain names into IP addresses.
Load Balancer: Distributes incoming requests to different servers.
Web Tier: Handles HTTP requests.
Application Tier: Handles business logic and computations.
Database Tier: Stores data and handles read/write requests​.

Question 3

Applications of MBAAS?

Answer 3

Fast development of mobile apps.
Unified backend management for cross-platform apps.
Handling user logins and notifications centrally.

Question 4

What is cloud computing?

Answer 4

Cloud Computing is the delivery of computing services (e.g. storage, processing, networking, and applications) over the internet rather than relying on local servers or personal devices

Question 5

Why is cloud computing important?

Answer 5

• No need to maintain physical infrastructure (cost efficient)
• Resources can be increased or decreased based on demand (scalable)
• Can access services rom anywhere with an internet connection (flexible)
• Cloud providers handle system updates and security (easily maintainable)
• Cloud providers often have failover and backup strategies (reliable)

Question 6

What are the three main service tiers of cloud computing?

Answer 6

Infrastructure as a Service (IaaS), Platform as a Service (PaaS), Software as a Service (SaaS)

Question 7

What is virtualization?

Answer 7

Technology that allows multiple virtual instances to run on a physical machine.

Question 8

What is PaaS?

Answer 8

PaaS provides a managed environment for developing, running, and managing applications without handling the underlying infrastructure.

Question 9

What does the Cloud Provider manage and what does the user manage for PaaS?

Answer 9

Cloud Provider: Hardware, OS, runtime, database, auto-scaling
User: Applications, data

Question 10

What does the Cloud Provider manage and what does the user manage for SaaS?

Answer 10

Cloud Provider: Complete software solution
User: Nothing

Question 11

Why is virtualization important?

Answer 11

It enables cloud providers to divide physical ardware resources into smaller manageable chunks, allowing multiple users to run different operating system and applications on the same physical server

Question 12

What is IaaS?

Answer 12

IaaS is the foundational model of cloud computing where the provider offers virtualized computing resources (servers, storage, and networking). The user controls the operating system and applications but not the physical hardware.

Question 13

What are the advantages of IAAS

Answer 13

Flexibility: Users can configure and run any OS or software.
Cost-saving: No need for physical hardware.
Scalability: Can scale up or down based on demand.
Resilience: Cloud providers manage failures, and workloads can be distributed across availability zones​.

Question 14

WHat are the main providers of IAAS?

Answer 14

Amazon Web Services (AWS): Amazon EC2 (Elastic Compute Cloud)
Microsoft: Azure
Google: Google Cloud Platform

Question 15

Advantages of PaaS

Answer 15

Pre-built infrastructure: Load balancers, databases, and runtime environments are managed by the provider.
Auto-scaling: Instances are created and removed automatically based on demand.
Cost-effective: Reduces the need for hardware and infrastructure management​.

Question 16

What is Amazon AWS Elastic Beanstalk?

Answer 16

Elastic Beanstalk is a PaaS offering by AWS that automates deployment, scaling, and monitoring of applications.
It supports multiple programming languages (Java, Python, Node.js, etc.).
Handles infrastructure scaling using Amazon EC2.
Provides built-in load balancing and monitoring with CloudWatch​

Question 17

What is SaaS?

Answer 17

SaaS delivers complete software solutions over the internet. Users access the software through a browser without needing to install or maintain it.

Question 18

Examples of SaaS

Answer 18

Email: Gmail, Yahoo Mail
Office Tools: Google Docs, Microsoft Office 365
Project Management: Atlassian Jira
CRM: Salesforce
Finance: TurboTax​.

Question 19

Advantages of SaaS

Answer 19

No installation: Direct access from a browser.
Lower costs: Pay-as-you-go model.
Automatic updates: Providers handle maintenance and updates.
Global access: Accessible from any location with internet access.

Question 20

Disadvantages of SaaS

Answer 20

Limited control: Customization options are limited.
Vendor lock-in: Moving data between providers may be difficult.
Performance issues: Dependent on internet connection and provider performance​.

Question 21

What is Mobile Backend as a Service (MBaaS)

Answer 21

MBaaS provides backend infrastructure for mobile and web apps, including:
Database integration
User authentication
Social media integration
Push notifications
Cloud storage

Question 22

What does the Cloud Provider manage and what does the User manage for IaaS?

Answer 22

Cloud Provider: Virtualized hardware, storage, networking
User: OS, applications, middleware

Question 23

What to consider when choosing a cloud service tier?

Answer 23

Level of Control: IaaS gives the most control; SaaS gives the least.
Cost: SaaS is usually subscription-based; IaaS and PaaS can be pay-as-you-go.
Scalability: PaaS and IaaS provide more options for scaling.
Customization: IaaS offers the most flexibility; SaaS is more fixed​.

Question 24

PaaS vs. IaaS

Answer 24

PaaS: Less control: Limited to programming environment, Less Complex because infrastructure is managed, Scalability is Handles automatically
IaaS: More control over OS and platform, More complex: have to specify architecture, Scalability requires user configuration

Question 25

What is the Shared Responsibility Model?

Answer 25

The Shared Responsibility Model defines the division of security and management tasks between the cloud provider and the customer. This model helps ensure that both the provider and the customer clearly understand their roles in maintaining a secure and efficient cloud environment​.

Question 26

What are the Cloud Provider's Responsibilities in the Shared Responsibiity Model?

Answer 26

Physical infrastructure (data centers, servers, and networking hardware). Hardware and software maintenance. Global infrastructure security (e.g., physical access control).

Question 27

What are the Customer's Responsibilities in the Shared Responsibility Model?

Answer 27

Configuring services securely. Managing user permissions. Safeguarding data (e.g., encryption, backups).

Question 28

Importance of IAM User Accounts

Answer 28

Root accounts have full access to all services—misuse can lead to catastrophic consequences. IAM allows: Creating different users with specific roles and permissions. Implementing the principle of least privilege (only give the necessary permissions).

Question 29

Importance of MFA

Answer 29

Adds an extra layer of security. Even if a password is compromised, the attacker cannot log in without the MFA code. Recommended to use an authenticator app over SMS for increased security​.

Question 30

Difference Between Stopping and Terminating an EC2 Instance

Answer 30

Stopping an EC2 Instance: Shuts down the instance. Preserves the associated storage (Elastic Block Storage - EBS). You are NOT charged for compute usage while stopped, but you ARE charged for the EBS volume and IP address (if attached). Terminating an EC2 Instance: Permanently deletes the instance. Associated storage (EBS) is deleted unless configured otherwise. Cannot recover the instance once terminated​.

Question 31

What is the key pair in an EC2 instance and why is it important?

Answer 31

The key pair (.pem file) is used to authenticate SSH access to the EC2 instance. Without the key pair, you cannot access the instance unless you have configured alternative access methods. Recommendations: Store key pairs securely (e.g., password manager). Do not share key pairs. Use separate key pairs for different environments (e.g., production, development

Question 32

What Are the Key Cloud Services?

Answer 32

1. EC2 (Elastic Compute Cloud) Virtual machines running in the cloud. Allows users to run applications on demand. 2. S3 (Simple Storage Service) Object storage service. Ideal for data storage, backups, and static file hosting. 3. Lambda Serverless computing. Runs code in response to events without needing to provision infrastructure. 4. VPC (Virtual Private Cloud) Isolated cloud network environment. Controls networking, IP addressing, and routing. 5. RDS (Relational Database Service) Managed relational database (MySQL, PostgreSQL, etc.). 6. DynamoDB Managed NoSQL database. Scalable with low-latency performance. 7. CloudWatch Monitors metrics and logs. Can trigger alerts based on performance issues or failures​.