Cloud Computing Intro

Question 1

Where is the biggest presence of data centers of Microsoft Azure?

Answer 1

Circa July 2016, In the north American continent,

followed by India and China, and Europe, and parts of Russia and Australia, and even some presence in south America

Question 2

Where did cloud computing start?

Answer 2

1. Distributed systems research (80’s, 90’s)
2. Grid computing (early 90’s)
3. NSF HPC (high performance computing) data centers (mid 90’s)
4. Resurrection of virtualization (late 90’s), orignally pioneered by IBM in the 6-‘s
5. Virtualization technologies, leading to companies such as VMWare (early 00’s)
6. Shrinking margins on selling “boxes” (mid 00’s)
7. “Services computing” model pioneered by IBM, computing as a utility

Question 3

What is Amazon’s definition of cloud computing?

Answer 3

The on-demand delivery of IT resources and applications via the Internet with pay-as-you-go pricing.

Question 4

What is IBM’s definition of cloud computing?

Answer 4

The delivery of on-demand computing resources - everything from applications to data centers - over the Internet on a pay-for-use basis.

Question 5

What are the characteristics of cloud computing?

Answer 5

1. computational resources (cpus, memory, storage) in data centers available as “utilities” via the Internet
2. Illusion of infinite computational capacity
3. Ability to elastically increase/decrease resources based on need
4. “Pay as you go” model based on resource usage
5. Application delivered as “services” over the Internet

Question 6

What are few of the many benefits of cloud computing?

Answer 6

1. No CapEx or OpRc for owning/maintaining computational resources.
2. Elasticity: being able to shrink/expand resources based on need
3. Maintenance/upgrades someone else’s problem
4. Availability - no down time
5. “pay as you go” model
6. business services can be “out sourced”
7. Disaster recovery of assets due to geographic replication of data

Question 7

What is the difference between a public cloud and a private cloud?

Answer 7

1. Public - resources are shared between users. virtualization at all levels, including the network traffic guarantees perfect isolation at resource level and performance level
2. Private - resources are physically dedicated to the individual user. Often the service provider may have the data center on user’s premises.

Question 8

What is “Cloud Bursting”?

Answer 8

In an hybrid cloud, “cloud bursting” is when a private cloud connects to the public cloud when demand exceeds a threshold

Question 9

When would we want to use an hybrid cloud?

Answer 9

When we have sensitive business logic and mission-critical data we would like to keep it in a private cloud. For easier maintenance we can keep more mundane services in public cloud.

Question 10

Explain the cloud service model “IaaS”

Answer 10

IaaS stands for Infrastructure as a Service. E.g: Amazon EC2.
In this model, the service provider offers to rent resources (cpus, memory, network bandwidth, storage).

Question 11

Explain the cloud service model “PaaS”

Answer 11

PaaS stands for Platform as a Service. E.g: Microsoft Azure.
In this model, in addition to renting resources, service provider offers APIs for programming the resources and developing applications that run on these resources.
This reduces the pain point for the cloud developer in developing, performance-tuning, scaling large-scale cloud apps.

Question 12

Explain the cloud service model “SaaS”

Answer 12

SaaS stands for Software as a Service. E.g: gmail, dropbox, Youtube, games.
in this model, service provider offers services to increase end-user productivity. User does not see physical resources in the cloud.