Introduction to Cloud Computing
1. How does Eli define Cloud Computing?The basic concept of cloud computing is to separate the applications from the operating systems and from the hardware that runs everything.
2. According to Eli, what does virtual computing do? Why is this advantageous?
Virtual computing places the operating system into container. This is advantageous because if the currecnt operating system fails, another one may replace it.
3. How does Eli relate virtual computing to cloud computing?
Virtual computing is a component of cloud computing.
4. In a cloud context, what is clustering?
Clustering is when two or more servers are working together using the same data.
5. What major application does Eli cite as being particularly friendly to clustering?
MySQL Cluster Database is very friendly towards clustering.
6. What happens when an individual server in a cluster fails?
Cluster realizes one of the server fails and will not send users to the fail clustered but will send users to one that works.
7. In a cluster context, what is replication?
This means every single database in the servers in the cluster contains the same information.
8. What does a terminal server do?
A terminal server (mainframe) supports the coexisting terminals.
9. What do we call the devices that terminal servers provide services to?
Thin Clients.
10. What are application servers? How do they differ from terminal servers?
Application servers have applications built upon the terminal services. Instead of a full desktop only the application will open up.
11. Eli cites two ways to do virtualization. What are they? When would you employ either one?
The two ways to do virtualization are
- Client Installed Virtual Software, where you install an Operation System on a piece of Hardware and on top of the Operation System install the client installed virtual software and create instances for different operation systems. This virtualization is employed to create DHCP or DNS, or FTP or Web servers by simply cutting the operating system from the instance and pasting it on another server.
- The way is Hypervisors, which is like a operating system that sits directly on the hardware (example ESXI) and is managed by a management software (like V sphere). This is employed in a situation where you want fault tolerance, for example you want uninterrupted email service during a power outage for one server.
12. What is the name of the free open source virtualization software?
Virtual Box.
13. Can you, without any other software, directly manage a hypervisor?
A hypervisor cannot be managed with software.
14. Amazon's EC2 environment was an early example of cloud computing. Describe the service and explain why an organization may find it compatible.
Amazon Elastic Compute Cloud (Amazon EC2) is a web service that provides cost based resizable computing capacity in the Amazon cloud based on the clients requirement. The client is only charged for the services used and it allows the client to install its operating system on the rented virtual cloud infrastructure, which is hosted by amazon.
15. What is a hosted instance?
A hosted instance is a cloud virtual server instance within a cloud network.
16. What is an edge server? Why are they significant?
An Edge server is a server that is geographically located in the country, which reduces the distance between the client and the server to give the best access to the server images uploaded to their systems. Edge servers store replications of network information in distributed networks. Edge servers also reduce latency because information is more readily available near people using the server.
17. What is dynamic bit rate switching? How can it impact your cloud computing billing?
Dynamic bit rate switching automatically adjusts streaming video quality based on a user's network speeds and hardware capabilities. The variability can affect the cost based on the speed and the amount of data transferred to the edge server, which can get really expensive for large files.
18. What is the difference between a hosted instance and a hosted solution?
Hosted instance: you create your own server by paying for the resources you need then install the software on top of it.
Hosted solution: applications or services that are hosted by the company that provides you the service. You rent the services.
19. Compare and contrast public and a private clouds.
Public cloud: hosted instances, all of the cloud-computing infrastructure that's up on the Internet that anybody can get access to.
Private cloud: specific users within an organization or company that are allowed access to that cloud. The cluster/hardware sits in your server room instead of the Internet.
