Recapture part 1 of Datacenters, an architecture approach
“Improving a data center starts with a proper understanding of the business model and the business architecture that is being used and not by a simple roll out of the newest technology.”
To meet the business and technology needs of a data center an architecture development method is wanted. To take an architecture approach in constructing a data center you first have to start with
- A proper comprehension of the business model that is being used …
- then you can formulate the business architecture and
- finally you can start with designing the IT architecture and defining a technical design and finding appropriate products.”
As a follow up we dive in to the business architecture of a data center. In making the business model, as discussed earlier, a general statement on the value proposition has been made. Therefore we now zoom in on this value proposition that was defined in the business model. But before we start we have to take some current developments in to account. The widespread adoption of a Service Oriented Business approach by means of virtualization technology and service oriented architecture (SOA) has a profound impact on the data center. It is therefore wise to describe a Service Oriented Data Center offering in terms of cloud computing service models. Also if the proposed data center is for internal use it is still wise to use general, cloud computing, service models. The NIST institute has made the following, draft, service model definitions:
- Cloud Software as a Service (SaaS). The capability provided to the consumer is to use the provider’s applications running on a cloud infrastructure. The applications are accessible from various client devices through a thin client interface such as a web browser (e.g., web-based email). The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user-specific application configuration settings.
- Cloud Platform as a Service (PaaS). The capability provided to the consumer is to deploy onto the cloud infrastructure consumer-created or acquired applications created using programming languages and tools supported by the provider. The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, or storage, but has control over the deployed applications and possibly application hosting environment configurations.
- Cloud Infrastructure as a Service (IaaS). The capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications. The consumer does not manage or control the underlying cloud infrastructure but has control over operating systems, storage, deployed applications, and possibly limited control of select networking components (e.g., host firewalls).”
We can add to this that in practice we can see that Platform as a Service has currently two flavours. A simple one, where the platform is a standardized operating system, or an extended one where also a standardized database and/or middleware environment is offered.
Another interesting cloud computing document used as input describes a Value Framework. The Value Framework, as described in “Do Clouds Compute? A Framework for Estimating the Value of Cloud Computing” by M. Klems et al. , presents an easy and very general usable framework for cloud computing. I have been working on the idea that it can also be used with some small changes and modifications to describe different kinds of data center value creations. This modified framework, see below, forms the business architecture of a data center.
It start with defining and explaining the business domain, this forms the link between the customer one has in mind and the value proposition. Then we get the business objectives. Is it about reducing costs, reducing time to create value or increasing quality and functions of the data center? In other words what is the main business objective we want to achieve. Also we have to pay attention to the demand behavior. Can we predict the demand of the customer in some way or another or not? Next question to be answered is which kind of service model you want to provide. There we use the NIST service model definitions, with two extensions: the extended PaaS model and the Colocation service. So is it just square meters (Colocation As A Service) or are you offering Software As A Service? Each standard service offering should have a well defined interface. Beware that the consumer does not manage or control the underlying components of the platform that is provided. The consequence is that by choosing one of the service models you are in fact ruling out certain customers because they want to manage or control certain components. Next step is to define the so called “technical requirements”. At this level of abstraction it is all about the service and/or quality you want to offer. So you have to be explicit about capacity/performance, availability, continuity, security and last but not least sustainability demands.
Now that we have al this information we can define the computing service, its function, the qualities and the quantities. Depending on the proposed service model you define your needs on software, processing power, storage, network and facilities (power, cooling, etc.) services. Where service stands for the sum of people, process & technology. This part forms the input for the resource costs. Here we can differentiate between capital expenditures (CAPEX) and operational expenditure (OPEX) and direct and indirect costs. To make ‘what-if’ analysis possible for different scenarios you can make and use a computing service reference model that has the same building blocks as the proposed scenarios.
By using this framework as a business architecture you have a tool for discussing your data center ideas or proposal with senior management.
Next time some words on performance management…