1. Lecture

Question 1

What is the cloud?

Answer 1

The practice of using a network of remote servers hosted on the internet to store, manage, and process data, rather than a local or personal computer.

Question 2

What are the different cloud computing deployment models?

Answer 2

IaaS: Infrastructure as a Service
PaaS: Platform as a Service
SaaS: Software as a Service

Question 3

What are the characteristics of IaaS?

Answer 3

• End-user applications delivered as a service, rather than by on-premise solutions
• Includes dedicated Virtual Machines (VM)
• Users configure the server type, operating systems …
• Scale up/down out/in

Question 4

What are the characteristics of PaaS?

Answer 4

• Application platform or middleware is provided as a service on which developers can build and deploy custom applications on.
• Delivers and manages various development environments
• Environment and tools can be easily provisioned and torn down

Question 5

What are the characteristics of SaaS?

Answer 5

• Computer, storing or other IT infrastructure are provided as a service, rather than as dedicated capability
• Internet hosted software
• Full vendor maintenance
• No upfront costs
• Pay for the services that are used

Question 6

Explain the service model division of responsibility

Answer 6

1. On-premises: Applications, Data, Runtime, Middleware, Operating system, virtualization, servers, storage, and networking is all managed by the user
2. IaaS: Applications, Data, Runtime, and Middleware are managed by the user.

The rest is managed by the provider.

3. PaaS: Applications and Data are managed by the user.

The rest is managed by the provider.

4. SaaS: Provider manages all responsibilities.

Question 7

What does to scale up/down (vertical scaling) mean?

Answer 7

Increase/decrease the CPU/memory or computing power of a VM

Question 8

What does scale out/in (horizontal scaling) mean?

Answer 8

Increase/decrease number of VM

Question 9

What are the cloud deployment models?

Answer 9

Private cloud
Hybrid cloud
Public cloud

Question 10

What is a private cloud?

Answer 10

• Intended for a single tenant
• Can help reduce operating expenses
• Leverage existing capital expenses

Question 11

What is a hybrid cloud?

Answer 11

• Bridges one or more private or public clouds

- Allows manipulation of CapEx and OpEx to optimize costs

Question 12

What is the public cloud?

Answer 12

• Shifts CapEx to OpEx
• Offers pay-as-you-go pricing
• Supports multiple tenants

Question 13

What are the advantages of using cloud services?

Answer 13

• Flexibility
• Reliability
• Cost-effectiveness (pay-as-you-go or consumption-based)
• Scalability
• Elasticity (Acknowledges peaks to increase resources)
• Current (No need for manual updating patches manually=
• Global
• Secure

Question 14

Which aspects are summarized under the term flexibility?

Answer 14

• Scale up and down to meet requirements
• Charge for services on a fine grain level
• Easy and agile to deploy
• Highly automated
• Device- and location-independent

Question 15

Which aspects are summarized under the term reliability?

Answer 15

• 24/7 support
• Vendor is responsible for hardware maintenance
• Vendor is responsible for software updates and maintenance for SaaS model

Question 16

Which aspects are summarized under the term cost-effectiveness?

Answer 16

• Reduce of Total cost of ownership (TCO)
• Free up internal resources
• Lower capital expenditure

Question 17

Describe a potential change/journey from on-premises towards SaaS

Answer 17

1. On-Premises -> IaaS: migration requires re-hosting
2. IaaS -> PaaS: requires complete application modernization, i.e.: refactor, rearchitect, and rebuild
3. PaaS -> SaaS: requires a full replacement

Question 18

What is a vendor lock-in?

Answer 18

• Company’s entire data is stored within a single vendor’s cloud storage
• The company relies on a single vendor for all of its computations
• Changing vendors can be very costly

Question 19

What are the typical services provided by the cloud provider?

Answer 19

• Computer power (e.g. web applications)
• Storage (e.g. files and databases)
• Networking (e.g. secure connections between provider and company using the services)
• Analytics (e.g. visualizing telemetry and performance data)

Question 20

What differentiates a VM, a container and serverless computing?

Answer 20

Serverless computing is only charged for the processing time used by each separate function. VMs and containers are charged while they are running, even if the applications are idle.

Question 21

What are typical CapEx computing costs?

Answer 21

• Server costs
• Storage costs
• Network costs
• Backup and archive costs
• Organization continuity and disaster recovery costs
• Datacenter infrastructure costs
• Technical personnel

Question 22

What are typical OpEx cloud computing costs?

Answer 22

• Leasing software and customized features
• Scaling charges based on usage/demand
• Billing at the user or organizational level

Question 23

What are the benefits of CapEx?

Answer 23

• Planning of expenses at the start of a project/period

- Fixed costs > appealing when planning with limited budget

Question 24

What are the benefits of OpEx?

Answer 24

• Pay-as-you-use
• No upfront costs
• Appealing if costs fluctuate
• Dynamically managing costs