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Defining the essential characteristics of the cloud May 8, 2012

Posted by janettheresjohn in Cloud Computing.
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Separating cloud computing from marketing hype and dealing with popular misconceptions

Cloud computing refers to the delivery of computing and storage capacity as a service to a heterogeneous community of end-recipients. Cloud computing entrusts services with a user’s data, software and computation over a network. [5] It is not the same as any of the traditional computing technologies. Cloud computing allow enterprises to be worry free about setting up and maintaining a data center. Cloud computing help them to get their applications up and running faster, with improved manageability and less maintenance, and enables IT to more rapidly adjust resources to meet fluctuating and unpredictable business demand. [5] In addition to helping large enterprises, cloud computing help small startup companies by bringing down the startup cost for small internet service based businesses.

A cloud service has three distinct characteristics that differentiate it from traditional hosting. [1] A could service is sold on demand. It is elastic so that a user can decide how much service they want at any given time.  Finally, a cloud service is fully managed by the provider.

Compared to the traditional computing model, which uses dedicated, in-house infrastructure, cloud computing has the unprecedented advantages in terms of cost and reliability. Cloud computing ensure reliability by using multiple redundant sites.  This makes a well-designed cloud computing system suitable for business continuity and disaster recovery.

Cloud customers pay for the service usage on demand. Cloud customers do not need to pay a large upfront cost before launching services. In traditional computing, the customers has to place a large investment to purchase and setup hardware infrastructure to provide a service. They may have to over-provision to accommodate future or peak demand. Cloud computing allow dynamic provisioning of resources on a fine-grained, self-service basis near real-time, without users having to engineer for peak loads. [5] This allows programs to continue running smoothly even as the number of users grows. Cloud service’s pay-as-you-go charging model enables the customer to pay for what they actually uses and promises to scale with demand. Moreover, customers can avoid the cost of maintaining an IT staff to manage their server and network infrastructure.

The services are broadly divided into three categories: Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS). In infrastructure- as- a -service model, the cloud service provider provides virtual server instances for customers to run their application. Customers can start, stop, access and configure their virtual servers and storage using the APIs provided by their chosen guest operating systems. This model allows companies to pay for only for the capacity that they needed, and expand capacity quickly as required. Some providers offer platform as a service (PaaS) model, where a cloud customer develops applications using the APIs provided by the cloud. In the software-as-a-service model, the provider supplies the hardware infrastructure, software and associated data are centrally hosted on the provider’s infrastructure. Most of the time, SaaS delivers a single application through the browser to thousands of customers using a multitenant architecture. With Saas model, from customers stand point, they don’t need to do any upfront investment in servers or software licensing and from the provider’s stand point, with just one app to maintain, and costs are low compared to conventional hosting. [4]

Cloud service providers offer a variety of options in pricing, performance, and feature set. Cloud providers differ in their pricing models. For example, Amazon’s AWS charges by the number and duration of VM instances used by a customer, while Google’s AppEngine charges by the number of CPU cycles consumed by a customer’s application. [2]

Studies show that there is no clear winner on the current cloud market who satisfies the needs of every customer. Cloud application designers has to decide which core functionalities of cloud computing is important for their application whether it is the computational power or data storage or something else. Based on the customer needs, they might have to choose one provider for storage intensive applications, another for computation intensive applications and pick and choose cloud solutions that fit their needs.

Currently, there are not standards for interoperability or data portability in the cloud. Since this is an evolving technology, it is still possible to develop some standards and some common APIs to prevent vendor lock-ins, and improve communication between different clouds. Moreover, it is very important to take privacy into account when designing cloud services that involve collection processing and sharing of personal data. Security safe guards should be used to prevent unauthorized access, disclosure, copying or modification of information.[3] Cloud service providers often apply data mining techniques to obtain marketing information. It is very important apply anonymisation techniques to protect personal data. Cloud services need to be more transparent since some regulatory compliance requires transparency into cloud. [3] Privacy issues are the major concern that reduce the adoption of cloud computing. Cloud service providers should keep this in mind when designing and developing new services.

Reference

  1. Cloud Computing, http://searchcloudcomputing.techtarget.com/definition/cloud-computing
  2. Ang Li,  Xiaowei Yang, Srikanth Kandula, Ming Zhang, CloudCmp: Comparing Public Cloud Providers
  3. Siani Pearson, Taking account of privacy when designing cloud computing services, HP laboratories, March 6, 2009
  4. Eric Knorr, Galen Gruman, What cloud computing really means, InfoWorld
  5. Cloud computing, http://en.wikipedia.org/wiki/Cloud_computing
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