Cloud Computing Questions

The mapreduce framework contains most of the key architecture principles of cloud computing such as:

- Scale: The framework is able to expand itself in direct proportion to the number of machines available.

- Reliable: The framework is able to compensate for a lost node and restart the task on a different node.

- Affordable: A user can start small and over time can add more hardware.

It depends on the type of business that demands a cloud setup. Suppose if the subscription on a public cloud for an application that is to be deployed on OS images is proving to be more costly then to buy some new datacenters and maintain them. Then obviously the a private cloud has to be setup instead of a public cloud. This public clouds follow utility billing methodology as electricity bill for example.

Cloud computing consists of 3 layers in the hierarchy and these are as follows:

1. Infrastructure as a Service (IaaS) provides cloud infrastructure in terms of hardware like memory, processor speed etc. 

2. Platform as a Service (PaaS) provides cloud application platform for the developers. 

3. Software as a Service (SaaS) provides cloud applications which are used by the user directly without installing anything on the system. The application remains on the cloud and it can be saved and edited in there only.

Amazon web services consist of a component called as Amazon S3 that acts as a input as well used as an output data store. It is used in checking the input and according to that gives the output. The input consists of the web that is stored on Amazon S3 as object and it is update frequently to make the changes in the whole architecture. It is required due to the on demand growing of the data set and to provide persistent storage.

Every architecture rely on a database that is easy to maintain and gets easily configured Amazon uses the database by the name SimpleDB. This is the database that is used for cloud architecture to track the statuses of the components. The component of the system are asynchronous and discrete, it requires capturing the state of the system so that in any failure the user can easily revert back to its normal configuration. SimpleDB is schema-less database and there is no need to define the structure before the creation of any data. Every controller in the database defines their own structure and link the data to a job.

Amazon SQS is a message passing mechanism that is used for communication between different connectors that are connected with each other. It also acts as a communicator between various components of Amazon. It keeps all the different functional components together. This functionality helps different components to be loosely coupled, and provide an architecture that is more failure resilient system.

API stands for Application programming interface is very useful in cloud platforms as it allows easy implementation of it on the system. It removes the need to write full fledged programs. It provides the instructions to make the communication between one or more applications. It also allows easy to create application with ease and link the cloud services with other systems.