One of the areas of confusion is the definition of Cloud Computing. There are many definitions of Cloud Computing out there. Here is one of them that seems to represent the most commonly held view. It’s from the National Institute of Standards (NIST) and seems to have gained in popularity, not only in the US, but also the rest of the world as well.
Cloud computing is a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.
Breaking it down, cloud computing is composed of:
- 5 essential characteristics
- 3 service models
- 4 deployment models
The 5 essential characteristics are:
- On-demand self-service – provisioning, monitoring, management control
- Resource pooling – implies sharing and a level of abstraction between consumers and services
- Rapid elasticity – the ability to quickly scale up/down as needed
- Measured service – metering utilization for either internal chargeback (private cloud) or external billing (public cloud)
- Broad network access – typically means access through a browser on any networked device
If you continue reading, we are going to explain a little bit deeper the 3 service models and 4 deployment models.
SaaS – “Software as a Service” generally refers to applications that are delivered to end-users over the Internet. There are hundreds of SaaS providers out there covering a wide variety of applications. Essentially every product being offered in On Demand’s products portfolio today, and accessible to our customers over the internet can be classified as a SaaS application.
PaaS – “Platform as a Service” generally refers to an application development and deployment platform delivered as a service to DEVELOPERS, allowing them to quickly build and deploy a SaaS application to end-users. There are a growing number of these in the market.
IaaS – “Infrastructure as a Service” generally refers to computing hardware (servers, storage and network) delivered as a service. This typically includes the associated software as well: operating systems, virtualization, clustering, etc. There are a growing number of infrastructure service providers such as Savvis, Tier 3, Rackspace, Amazon Web Services and Microsoft Azure. IaaS providers that target enterprise and mid-market customers generally offer a high-quality service, with excellent availability, good performance, high security and good customer support.
NOTE: This market is wholly separate and distinct from cloud Platform as a Service – PaaS and Software as a Service – SaaS.
Depends on your business whether you need to build more or less cloud applications and services. In the picture we can see, the Cloud provider offers to their client at least the Infrastructure as a Service (IaaS). On top of that customers can build any application they want from practically scratch. Clients won’t need to buy hardware, virtualization, OS, Data Bases, because server, storage and network hardware and associated software are delivered as a service.
But Cloud Providers today, offer PaaS as well, where App development & deployment platform are delivered as a service. The following picture gives a flavor why a client should choose IaaS or PaaS.
The basic idea is that PaaS provides balance between flexibility and ease of use for the departmental cloud customers, providing enough in the cloud so that cloud tenants can get up and running quickly and easily but have enough latitude and flexibility to create the applications they really need. Only IaaS level provides each tenant with the basic cloud infrastructure, and cloud customers must reinvent the wheel and build most of the stack on his own (but they have the freedom to do it), lengthening time-to-deployment and resulting in inconsistent stacks that are harder to manage. By providing more in a PaaS model, tenants not only get up and running more quickly, but Central IT’s management, security, and efficiency is greatly enhanced through consistency and economies of scale.
SaaS – Applications delivered as a service to end-users typically through a Web browser. There are hundreds of SaaS service offerings available today, ranging from horizontal enterprise applications to specialized applications for specific industries, and also consumer applications such as Web-based email. Many companies today also offer enterprise-grade enabling technology to Independent Software Vendors (ISVs) to build their own SaaS offerings, a sort of Platform for SaaS. Hundreds of ISVs have built their SaaS offering on top of these Platforms for SaaS.
Over the last year cloud infrastructure providers or IaaS, has become popular topic of conversation among INH customers. Browsing through Gartners’ newest report on IaaS, we were amazed on the number of Cloud Infrastructure Providers there are out there. Well IaaS providers are Amazon Web Services (AWS), Rackspace, etc., but as you will see below there are several others worth looking at (IaaS – Gartner Magic Quadrant).
Recently speaking with some INH customers, we began discussing the various Cloud Infrastructure Providers available. We were able to name a handful, but found ourselves wondering if perhaps something was missing. Fortunately we stumbled across the Gartner Magic Quadrant for IaaS recently released in May 2014. The intention of this article is not to evaluate each cloud infrastructure provider in the picture below, however a good starting point of reference for someone who is looking at this an option to moving their data center to a more cloud based approach.