We’ve heard a lot about cloud computing over the last years. Since the middle of 2007, searches for the term have been booming, and although, according to Google Trends, the trend has reversed somewhat lately, today’s “Google meter” was at 105 million pages. Many cloud definitions have been developed, but the one I always refer to is the one from NiST, the National Institute of Standards and Technologies, as it addresses many of the cloud specifics and is precise enough to differentiate cloud and cloud look alike offerings.
Now, that definition introduces, like many others, the concepts of IaaS, PaaS and SaaS. Somehow, many people have the impression these three concepts are like Russian puppets. A SaaS automatically contains a PaaS which in turn contains an IaaS. Well in fact that is absolutely wrong.
Each of them is built on a Cloud Platform, a hardware/software stack that contains the common elements required for a cloud offering to work. Separating this base functionality from the actual services allows providers (internal or external) to develop multiple services (even from different types) on the same platform. Such platform includes three main functionalities, a demand, supply and delivery function. The HP Cloud Functional Reference Architecture focuses on those three functions and as such depicts the requirements of such Cloud Platform. Let’s look at each in a bit more details.
Let’s start with the demand function. This one includes a service request function, in other words, the possibility to set-up a user portal through which services can be requested. Obviously, the content of the portal will be related directly to the type of services provided. It’s actually the service catalog that contains the service descriptions and other information, leaving the portal service agnostic. The base portal functionality and its linkage with provisioning, configuration and usage reporting are actually common to all types of services.
The demand layer also includes a billing function, which will be different for a private or a public cloud, and a basic service health, SLA management environment. Finally a service portfolio management environment is required to allow the service manager to describe the service, potentially establish its price and define which users have access to the service. Again, the content will depend on the service delivered, but the “reservoir” should be there.
The supply function includes the resources (servers, storage, networking, software etc.) that will be provisioned and configured to deliver the appropriate service. This will be complemented with resource management including release, health check etc.
Finally, the delivery function includes the service configuration and activation, delivery assurance (which in turn links with SLA management), the actual charging and user/order management. We should realize that a service can be complex, including multiple service elements. For example, a project team collaboration service may include a SharePoint site, a wiki, a forum, a virtual room and a chat function. When a user requests such service, each of those components will have to be provisioned.
The delivery layer also has another function, the management of the complete lifecycle. Too often cloud is talked about as a way to provision services. Unfortunately software often needs to be patched, reconfigured or upgraded. And this is also required for all instances of the service that have been provisioned. The delivery layer automates the management of the service lifecycle for each service instance, from provisioning to release. And this should never been forgotten. The extreme focus on IaaS, and leaving the management of the software stack running on the virtual server, makes us lose track of this important aspect.
Both supply and delivery share a service management and governance function.
On top of these common elements, a service provider (being it an IT department or a public cloud provider) can now develop simple services such as CPU as a service, or Storage as a service, but also more complex environments such as development platforms as a service, or even business functionality such as ERP or CRM as a service. Each of those services will now use the common platform services, allowing appropriate charging of a user that combines IaaS and SaaS services for example.
Why this aspect is most often missed out is a mystery for me. It really makes the offering very clean and allows companies to expand their offering moving forward. Make sure that, when you talk to your supplier about his cloud environment, you understand what the cloud platform will deliver. Ask whether it goes beyond provisioning and includes full service lifecycle management. Let me reassure you, HP CloudSystem includes these functions in all three of its offerings.