IntroductionOne of the overall design goals of computing technology is to create a computing system whichis capable of meeting almost all of the present and near-future requirements of a largecomputer utility that can run continuously and reliably 365 days in a way similar to telephoneor power systems, and must be capable of meeting wide service demands with noinfrastructure investments.Today, after four4 and half decades, that vision appears close to becoming reality, a newTechnology started to compete with traditional software through its technological advantagesand economy of scale i.e. “Cloud computing”.Cloud computing is a new model of delivering computing resources. This term refers to On-demand, self-service internet infrastructure that enables the user to access computingresources anytime from anywhere. The essence of cloud computing is to make datacenterhardware and software available to the general public on a pay-as-you-go basis.This computing technology is moving forward so quickly from Colocation to Managed servicesto Cloud computing. Below table depicts how overall system improved interms of Time,Scalability, Cost, pricing from collocation to cloud computing. Colocation Managed services Cloud ComputingTime Weeks to Months Days to Weeks MinutesScalability Slowest, Rigid & Costly Slower, somewhat Instant, Flexible, Pay- flexible, Costly per-usageCost High CapEx Costly, sometimes No contracts, usage month/year contracts, based, no upfront costs no CapExPricing Model Buy Servers & Colo Rent Servers & Hosting Rent based on usage costs whether used or costs whether used or only not not
In 2008, many companies, such as Amazon, Google and Microsoft Hotmail announced theavailability of Private and public clouds that delivered proprietary SaaS (software as a service)model.From a service point of view, cloud computing is of three types, Software as a Service: This service generally says “Just run it”. So, Applications are hosted by a Service provider and made available to customer though Internet Services. Example: Amazon’s EC2, Google Apps, Facebook, Salesforce.com CRM, Lotus Live Platform as a Service: This service generally says “Give me API and take care of the implementation”. So the development tools are hosted in the cloud and accessed through API. With PaaS, developers can build Web applications without installing any tools locally, and then deploy applications without any specialized skills. Example: Force.com, Google App Engine, Windows Azure Infrastructure as a Service: This service says “Why to buy machines when you can rent cycles”. So, the user outsources the equipment used to support owns the equipment and is responsible for housing, running, and maintaining it. The user typically pays on a per-use basis. Example: Gmail, Amazon WebservicesDeployment models: Public cloud: A cloud service provider makes resources available to the public over the Internet on a pay-as-you-go basis. Example: Amazon Elastic Compute Cloud (EC2) runs within Amazon’s network infrastructure and data centers and allows customers to pay only for what they use with no minimum fee. Private cloud: Proprietary network or the data center supplies hosted services to a group of people. Example: Microsoft Azure enables customers to build the foundation for a private cloud infrastructure using Windows Server and System Center family of products with the Dynamic Data Center Toolkit.
Community cloud: The cloud infrastructure is shared by several organizations with common concerns. Example: Google GovCloud provides the Los Angeles City Council with a segregated data environment to store its applications and data that are accessible only to the city’s agencies. Hybrid cloud: The cloud infrastructure comprises 2 or more clouds. In this infrastructure, an organization provides and manages some resources within its own data center and has others provided externally. Example: IBM collaborates with Juniper Networks to provide a hybrid cloud infrastructure to enterprises to seamlessly extend their private clouds to remote servers in a secure public cloud
Pros and Cons of Cloud Computing: Technical Issues: o Security: There is no point to worry for disk failures or a disaster at your place. All the data is stored in the cloud. Cloud instances are isolated in the network from other instances for improved security. Challenge: There are many data security risks, such as hacker attacks, network breaks, natural disasters, separation failure, public management interface, poor encryption key management, and privilege abuse. Specific risks to cloud computing are separation failure, public management interface, poor encryption key management, and privilege abuse. Able to be access anywhere and on a shared network. Most cloud systems are not compliant with PCI, SSAE 16, and HIPAA standards. o Technology: Eliminating the new infrastructure cost and these IT maintenance burdens. When the app is web-based, updates happen automatically this will lessen upgrade costs. Challenge: Several technical challenges related to the use of cloud computing include resource exhaustion, unpredictability of performance, data lock-in, data transfer bottlenecks, and bugs in large-scale distributed cloud systems Operational and Organization Issues: o Cost: Any organization can focus on their task without incur additional cost towards trainings, hardware infrastructures, speedy deployments. Challenge: Lack of trust in data security and its privacy, governance issues o Complexity of Application: o Performance: Since no software or Servers are loaded on local machines, and connects from data centers, Users will never experience delays in execution. Challenge: Since user will never know how servers will work i.e. lack of control on servers and what the issue in case of any delays.References: 1. YouTube Cloud computing Video 2. Google Sites 3. The Future of cloud computing