In my previous post, I defined and differentiated, How principles of virtualisation can help you to understand cloud computing. I have identified the main cloud services on demand that are Infrastructure as a Service (IaaS), Platform as a Service (PasS), the software service -Software as a Service (SaaS).
Cloud computing is a way to manage virtualised IT resources. Servers, workstations, network, software is remotely managed and demand is deployed. The connected network of servers is grouped together to divide the load generated on site and manage uptime of a website even in critical traffic situations. Cloud servers need no time for hardware installation so it is the purchase of a managed IT service through an online ordering interface. You buy only what you consume. The most popular cloud services are the services infrastructure, the service, and the software platform.
Infrastructure as a Service (IaaS) is the use of infrastructure or virtual machines on demand. The supplier is responsible for the network elements, transit, and virtual servers. The consumer, however, is responsible for the installation and operation of its operating system and its applications.
For a business, this first case is interesting only if it has sufficient human resources expert to manage itself the operation of its IT platforms.
Benefits of the IaaS model include:
No investment in hardware
Pay per Costing
Physical security of data centers locations for servers
The platform as a service (PaaS) is an enhanced version of service infrastructure (IaaS). The company has an on-demand infrastructure that can be adjusted according to the needs. Also, it has a minimum service from its service provider, since it is also responsible for operating systems and certain licenses, such as databases.
In PaaS, the resources and software needed for the hosting of its platform and service is used for production. The service provider will install and configure servers, operating systems, databases and required licenses. The consumer will still be responsible for setting its applications and operations.
The advantage is that the company has a highly flexible and scalable service. According to its needs, it can adjust its platform. For example, if eUKhost found something that could cause a peak load on its client website, it can quickly increase the technological resources and without interruption or direct impact to its customers.
Benefits of the PaaS model include:
Server-side scripting environment
Database management system
Tools for design and development
The software service (SaaS) is the most “advanced” version of the cloud service. Your service provides a complete platform, including operating systems, software and specific applications. It is a software distribution model in which applications are hosted by a service provider and made available to client over a network.
Benefits of the SaaS model include:
Automatic updates and patch management
Compatibility: All users will have the same version of the software.
Easier collaboration, for the same reason
SaaS applications are designed for end-users, delivered over the web, so provider has to take care of the installation and configuration of all servers and applications (web server, mail server, database integration the software). SaaS really include all tasks related to the operation of the platform, servers and operating systems, including monitoring, responding to incidents, patch management, security or, on the contrary, it will include only the relevant monitoring platform without actually respond to problems and without contractual service level that can be subject to penalties.
To avoid unpleasant surprises, before subscribing to a service, ask about the parameters that are actually supported by your service provider because it is your reputation and even your revenue that depends on management.
For example, consider the case of an e-commerce site: when one considers that 17% of shoppers choose to purchase a site based on its availability if it is poorly managed, each downtime rhyme with a bad reputation and loss of money. Furthermore, the more you climb the ladder of the service, the less you are working on your platform. In IaaS, you are working a lot on your platform, PaaS mode, you are working less, and SaaS, you do nothing at all!
Cloud computing offers many possibilities and plenty of efficient services, but it also has limitations. This is the case, for example, applications that are specifically within your IT applications with increased security requirements, or applications where large data cloud computing is not recommended due the power required treatment.