Cloud computing is one of the latest computer industry buzz words. It joins the ranks of virtual computing, grid computing, and clustering, among others. The term cloud computing is sometimes ill-defined, which has led many IT professionals and management to make assumptions as to what cloud computing does and how their companies can best utilize it.
Cloud computing is an Internet-based computing, which uses shared resources, software and information. Cloud computing is the separation of the hardware and the software using virtualization software such as VMware’s vSphere. In general, cloud computing means customers do not own the physical infrastructure and avoids capital expenditure by renting usage from a third-party provider. They consume resources as a service and pay only for resources that they use, usually on per minute or per hour basis. Several of the major providers with cloud offerings include Amazon Elastic Compute Cloud (EC2), IBM Blue Cloud, Sun Cloud, Google App Engine, Amazon Web Services, and Force.com.
Key features of Cloud Computing
- Agility improves with users’ ability to rapidly and inexpensively re-provision technological infrastructure resources.
- Cost is claimed to be greatly reduced and capital expenditure is converted to operational expenditure. This ostensibly lowers barriers to entry, as infrastructure is typically provided by a third-party and does not need to be purchased for one-time or infrequent intensive computing tasks. Pricing on a utility computing basis is fine-grained with usage-based options and fewer IT skills are required for implementation (in-house).
- Device and location independence enable users to access systems using a web browser regardless of their location or what device they are using (e.g., PC, mobile). As infrastructure is off-site (typically provided by a third-party) and accessed via the Internet, users can connect from anywhere.
- Multi-tenancy enables sharing of resources and costs across a large pool of users thus allowing for:
- Centralization of infrastructure in locations with lower costs (such as real estate, electricity, etc.)
- Peak-load capacity increases (users need not engineer for highest possible load-levels)
- Utilization and efficiency improvements for systems that are often only 10–20% utilized.
- Reliability is improved if multiple redundant sites are used, which makes well designed cloud computing suitable for business continuity and disaster recovery.Nonetheless, many major cloud computing services have suffered outages, and IT and business managers can at times do little when they are affected.
- Scalability via dynamic (“on-demand”) provisioning of resources on a fine-grained, self-service basis near real-time, without users having to engineer for peak loads. Performance is monitored and consistent and loosely coupled architectures are constructed using web services as the system interface. One of the most important new methods for overcoming performance bottlenecks for a large class of applications is data parallel programming on a distributed data grid.
- Security could improve due to centralization of data, increased security-focused resources, etc., but concerns can persist about loss of control over certain sensitive data, and the lack of security for stored kernels. Security is often as good as or better than under traditional systems, in part because providers are able to devote resources to solving security issues that many customers cannot afford. Providers typically log accesses, but accessing the audit logs themselves can be difficult or impossible. Furthermore, the complexity of security is greatly increased when data is distributed over a wider area and / or number of devices.
- Maintenance cloud computing applications are easier to maintain, since they don’t have to be installed on each user’s computer. They are easier to support and to improve since the changes reach the clients instantly.
- Metering cloud computing resources usage should be measurable and should be metered per client and application on daily, weekly, monthly, and annual basis. This will enable clients on choosing the vendor cloud on cost and reliability (QoS).
Source: http://en.wikipedia.org/wiki/Cloud_computing
Leave a Reply