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Amazon Elastic Compute Cloud (EC2): This is a business web service which enables clients to lease personal computers on which to run and convey their personal computer applications. EC2 permits versatile arrangement of office applications by providing a web services interface and an organization platform over which a client can make virtual machines (VM), for example, server cases, where the client can put and run the product of their choice.

Amazon announced a limited public beta test of EC2 on August 25, 2006. Access to EC2 was allowed on a first-come, first-served basis. For the most part, EC2 turned out to be accessible on October 23, 2008 with the help of Microsoft Windows Server.

Amazon.com facilitates customer access with EC2 cloud as one of a few web services advertised under the sweeping title Amazon Web Services (AWS).¹ It started its service as IaaS clouds with a variety of services, including S3 (for storage), CloudFront (content delivery), SimpleDB (for structured data storage), SQS (for reliable messaging), CloudFront Streaming (for video streaming), RDS (for relational database), and Elastic MapReduce (for information processing).

 Small Instance: The small instance (default) likens to “a framework with 1.7 GB of memory, 1 EC2 Compute Unit (1 virtual center with 1 EC2 Compute Unit), 160 GB of storage space, 32-bit framework.”

 Large Instance: The large instance depicts “a framework with 7.5 GB of memory, 4 EC2 Compute Units (2 virtual cores with 2 EC2 Compute Units each), 850 GB of storage space, 64-bit framework.”

 Extra Large Instance: The extra-large occurrence offers “what might as well be called a framework with 15 GB of memory, 8 EC2 Compute Units (4 virtual cores with 2 EC2 Compute Units each), 1690 GB of storage space, 64-bit framework.”

Amazon charges customers in two primary ways:

 Hourly cost/VM.

 Information exchange cost.

The hourly VM rate is arrived at in view of the limit and enhancements of the VM. Amazon publicizes the evaluation plan as “pay for resources you consume.”

Clients can begin and stop VMs to manage costs without much trouble, with Amazon estimating with hourly granularity. Few are ready to keep each virtual machine running close to the limit and pay just for CPU time really used.

FlexiScale: This is a UK-based CSP that offers services which are equivalent to Amazon Web Services. The virtual servers of this cloud provider offer features such as persistent storage by default, dedicated VLAN, fixed IP address, runtime adjustment of CPU, and a wider range of server sizes. FlexiScale cloud services are also priced by the hour.

In the current scenario in the UK, FlexiScale cloud is providing services such as Web service (SOAP), access to virtual server through SSH (Linux), web-based user interfaces, Remote Desktop (Windows), per hour pricing, automatic scaling, and in case of hardware failure, automatic recovery of VMs as per SLA.

GoGrid:² Similar to other IaaS CSPs, GoGrid permits its clients to use a wide range of Windows and Linux images, with a scope of fixed instance sizes. GoGrid provides the services like “value-added” stacks, which are prioritized more for various applications like e-commerce, web hosting and database services.

It also provides a new feature which makes it easier for customers to combine traditional dedicated hosts with the autoscaling infrastructure facility. Customers can take the benefits of dedicated hosting combined with on-demand cloud infrastructure, which leads to the user getting the advantages of each paradigm of computation.

Rackspace Cloud:³ Rackspace provides infrastructure service that offers fixed instances of VMs in the cloud. Rackspace provides a wide scope of pre-made Linux-based images. In this cloud, RAM is measured per user-requested images. Like GoGrid, Rackspace servers combine dedicated hosts with cloud infrastructure to facilitate the customers accessing all of the features of automated cloud computing. It offers advantages such as enabling static (fixed) IP address, load balancing, and persistent storage.