Armbrust et al: A view of cloud computing

Cloud Computing- Both the applications delivered as services over the internet and the hardware and systems software in the data centers that provide those services.

Iaas- Infrastructure as a Service

Saas- Software as a Service

Paas- Platform as a Service

How are they related?
Saas makes up the software (applications delivered over the internet) aspect of cloud computing while Iaas and Paas make up the hardware (low level infrastructure and higher-level platform). This article in particular describes Iaas and Paas as more alike than than different, so it groups them together.

What is a private cloud versus a public cloud? How do they differ? 
"When a cloud is made available in a pay-as-you-go manner to the general public, we call it a public cloud; the service being sold is utility computing. We use the term private cloud to refer to internal data centers of a business or other organization, not made available to the general public, when they are large enough to benefit from the advantages of cloud computing that we discuss here." (p.51)

What do the authors state as the key necessary enabler of cloud computing? 
 They say that the "construction and operation of extremely large-scale, commodity-computer data centers at low-cost locations was the key necessary enabler of cloud computing."

Summarize the use cases that favor utility computing over conventional hosting. 
1. Demand for a service varies with time. Example: Having a data center with the equipment to handle its peak utilization which only happens a few days a month. This leads to under utilization the rest of the time. This would allow my company to save money and only use what I need.

2. Demand is unknown in advance. Example: A website is launched and gets a high amount of traffic initially, but dies down in time. It can then be reduced once it slows. Same idea, I only use what I need.

3. When an organization needs to perform batch analytics, they can use cost associativity of cloud computing to finish computations faster. Example: Using 1000 EC2 machines rather than a single machine for 1000 hours. This saves a vast amount of time but then saves money in the long run by not needing to have the 1000 machines once it is over.

Reading 2 - Social Networks That Matter: Twitter Under the Microscope

 Consider your social media networks:

Is there a noticeable subset of strong friends/followers? 

Twitter:

My twitter is mostly comprised of businesses that i like, interesting or funny made up personalities, and some friends. I generally don't talk with my real life friends on twitter as much as other social networks such as Facebook. I generally use twitter to spread/share important information or things i like, ask a business a question, or responded to a friends tweet from time to time. There is not really a large subset of friends vs followers mainly because a majority of my followers are not my friends.

Facebook:

I would consider Facebook as my favorite and "main" social network that i use. I am friends on Facebook with just about every one of my real life friends, as well as a ton of other acquaintances, friends of friends, and some businesses. While i am friends with most of my real life friends on Facebook, i also have many people that i do not talk with anymore or have not even met as friends. There is definitely a strong subset of friends vs followers on Facebook for me. There is a clear line of people that i do not talk to, and those who i contact all the time.


Do you have multiple sub-networks?

I would say that i do in fact have multiple sub networks. There are my real life friends, my family members, my acquaintances, people i have never met before but thought were interesting, businesses, and made up personalities on twitter (these are things such as the Batman titter or the Chuck Norris twitter. They are run by real people impersonating a personality). Each of these subsets represent a completely different purpose for being friends/following with. I communicate with each of these differently and for different reasons. Friends for fun, family to keep in touch, businesses for news, new products, or questions, and personalities for entertainment.