Cloud Computing Questions

Security is one of the major aspects which come with any application and service used by the user. Companies or organizations remain much more concerned with the security provided with the cloud. There are many levels of security which has to be provided within cloud environment such as:

• Identity management: it authorizes the application service or hardware component to be used by authorized users.

• Access control: permissions has to be provided to the users so that they can control the access of other users who are entering the in the cloud environment.

• Authorization and authentication: provision should be made to allow the authorized and authenticated people only to access and change the applications and data.

Cloud computing architecture consists of many layers which help it to be more organized and can be managed from one place. The layers are as follows:

1. Cloud controller or CLC is the top most level in the hirerachy which is used to manage the virtualized resources like servers, network and storage with the user APIs. 

2. Walrus is used for the storage and act as a storage controller to manage the demands of the users. It maintains a scalable approach to control the virtual machine images and user data.

3. Cluster Controller or CC is used to control all the virtual machines for executions the virtual machines are stored on the nodes and manages the virtual networking between Virtual machines and external users.

4. Storage Controller or SC provides a storage area in block form that are dynamically attached by Virtual machines. 

5. Node Controller or NC is at the lowest level and provides the functionality of a hypervisor that controls the VMs activities, which includes execution, management and termination of many instances.

There are four phases that basically gets involved in the cloud architecture:

1. Launch phase: it launches the basic services and makes the system ready for communication and for application building

2. Monitor phase: it monitors the services that is being launched and then manages them so that on demand the user will be able to get what he wants.

3. Shutdown phase: it shutdown the services that are not required first and after all the services gets shutdown, and then it closes the system services. 

4. Cleanup phase: it clean up the left out processes and services that is being either broken or didn’t get shutdown correctly.

Cloud computing is a metaphor used for internet. It provides on-demand access to virtualized IT resources that can be shared by others or subscribed by you. It provides an easy way to provide configurable resources by taking it from a shared pool. The pool consists of networks, servers, storage, applications and services.