Having dealt with the basics of what cloud computing is, let us go further to understand more on this subject and talk about the main characteristics and deployment models. With so much of hype surrounding the topic, simple matters often get missed out, leaving us a bit skeptical of its utility. Many therefore stay unsure, wondering, whether this solution is appropriate for them or whether this is the right time for them to do so.
We can look at the advantages of cloud computing and examine if this would benefit us. Cloud computing exhibits the following key characteristics:
1. Reduction in costs: The cloud model (especially the public cloud) works on a shared delivery model, which enables sharing of resources and costs across a large pool of users and therefore brings down costs. Instead of companies making capital investments, they incur operational expenses. This 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 is on a utility computing basis and the user is charged only for the resources used.
2. Agility: Since resources are provided ‘on demand’, it brings in agility, thereby, improving users’ ability to re-provision technological / infrastructure resources. Therefore, it ensures scalability and elasticity in provisioning resources on a self-service and near real-time basis.
3. Device and location independence: Users are able to access systems using a web browser, regardless of their location or what device they are using (e.g., PC, mobile phone). As infrastructure is off-site (typically provided by a third-party) and accessed via the Internet, users can connect from anywhere.
4. Peak-load capacity management: In normal cases, we deploy infrastructure to meet peak load demands, and which lays idle at other times. This problem is taken care of by provision resources on demand. There are utilization and efficiency improvements for systems that are often only 10–20% utilized.
5. Reliability: Service levels are assured through the SLAs signed and the service provider usually provides for multiple redundant sites, which makes well-designed cloud computing architecture suitable for business continuity and disaster recovery.
6. Performance monitoring: SLAs should cover performance monitoring services that the partner must provide. The user company can thus be relieved of this responsibility.
7. Security: The subject of security is often discussed and there are huge concerns especially on the public cloud model. In my opinion, security could improve due to centralization of data, increased security-focused resources, etc. Nonetheless, concerns can persist about loss of control over certain sensitive data, and the lack of security when on shared platforms.
Various models of deployment are possible and organizations have been using them for a while. Let us discuss two of them which are usually debated.
The public cloud: A public cloud is one based on the standard cloud computing model, in which a service provider makes the resources, such as applications and storage, available to the general public, over the Internet. Public cloud services may be offered on a pay-per-usage model. Since this is based on a shared services model, it really helps in bringing down costs.
The private cloud: Private cloud is infrastructure operated solely for a single organization, whether managed internally or by a third-party and hosted internally or externally. It is the so-called private cloud, where companies, in effect, try ‘cloud computing at home’ instead of turning to an Internet-based service. The idea is that you get all the scalability, metering, and time-to-market benefits of a public cloud service without ceding control, security, and recurring costs to a service provider.
The private cloud model has, however, attracted criticism because users ‘still have to buy, build, and manage them’ and thus do not benefit from lower up-front capital costs and less hands-on management. Adoption of the public cloud is largely influenced by concerns of security and I am sure that as the concept matures and the security issues are addressed, larger number of organizations will be seen on the public cloud.