Data Center Architecture and Technologies in the Cloud
This chapter provides an overview of the architectural principles and infrastructure designs needed to support a new generation of real-time-managed IT service use cases in the data center. There are many process frameworks and technologies available to architects to deliver a service platform that is both flexible and scalable. From an operational perspective, maintaining visibility and control of the data center that meets the business's governance, risk, and compliance needs is a must. This chapter will discuss the building blocks, technologies, and concepts that help simplify the design and operation, yet deliver real IT value to the business, namely, business continuity and business change.
Architecture is a borrowed term that is often overused in technology forums. The Oxford English Dictionary defines architecture as "the art or practice of designing and constructing buildings" and further, "the conceptual structure and logical organization of a computer or computer-based system."
In general, outside the world of civil engineering, the term architecture is a poorly understood concept. Although we can understand the concrete concept of a building and the process of building construction, many of us have trouble understanding the more abstract concepts of a computer or a network and, similarly, the process of constructing an IT system like a service platform. Just like buildings, there are many different kinds of service platforms that draw upon and exhibit different architectural principles.
As an example of early architectural prinicples, requirements and/or guidelines (also known as artifacts), Figure 3-1 depicts the the famous drawing of Leonardo Da Vinci's "Vitruvian Man." We are told that the drawing is based on the ideas of a Roman Architect Marcus Vitruvius Pollio that a "perfect building" should be based on the fact (the mainly Christian religious idea) that man is created in the image of God and thus provides the blueprint of "proportional perfection" (that is, the relationship between the length of one body part to another is a constant fixed ratio). It was believed that these ratios can serve as a set of architectural principles when it comes to building design; thus, a "perfect building" can be acheived. Obviously, our ideas on architecture and design are much more secular and science-based today. That said, the Vitruvian Man provides a good a example of the relationship of architecture to design and its implimentation.
Figure 3-1 Leonardo da Vinci's Vitruvian Man (Named After the Ancient Roman Architect Vitruvius)
Even though architecture involves some well-defined activities, our first attempt at a definition uses the words art along with science. Unfortunately, for practical purposes, this definition is much too vague. But, one thing the definition does indirectly tell us is that architecture is simply part of the process of building things. For example, when building a new services platform, it is being built for a purpose and, when complete, is expected to have certain required principles.
The purpose of a "service delivery platform" is usually described to an architect by means of requirements documents that provide the goals and usage information for the platform that is to be built. Architects are typically individuals who have extensive experience in building IT systems that meet specific business requirements and translating those business requirements into IT engineering requirements. It is then up to subject matter experts (for example, server virtualization, networking, or storage engineers) to interpret the high-level architectural requirements into a low-level design and ultimately implement (build) a system ready for use. Figure 3-2 shows the many-to-one relationship among architecture, design, and implementations. Note that clear and well-understood communication among all stakeholders is essential throughout the project delivery phases to ensure success.
Figure 3-2 Architecture Shapes the Design and Implementation of a System and/or Service
Therefore, architecture is primarily used to communicate future system behavior to stakeholders and specify the building blocks for satisfying business requirements (this data is normally referred to as artifacts). A stakeholder is usually a person who pays for the effort and/or uses the end result. For example, a stakeholder could be the owner or a tenant of a future service platform, or a business owner or user of an anticipated network. Architecture blueprints are frequently used to communicate attributes of the system to the stakeholders before the system is actually built. In fact, the communication of multiple attributes usually requires multiple architecture documentation or blueprints. Unfortunately, architecture diagrams (usually multiple drawings) are often used incorrectly as design diagrams or vice versa.
With regard to cloud services, architecture must extend beyond on-premises (private cloud) deployments to support hybrid cloud models (hosted cloud, public cloud, community cloud, virtual private cloud, and so on). Architecture must also take into consideration Web 2.0 technologies (consumer social media services) and data access ubiquity (mobility).
Architectural principles that are required for a services platform today would most likely include but not be limited to efficiency, scalability, reliability, interoperability, flexibility, robustness, and modularity. How these principles are designed and implemented into a solution changes all the time as technology evolves.
With regard to implementing and managing architecture, process frameworks and methodologies are now heavily utilized to ensure quality and timely delivery by capitalizing of perceived industry best practices. Chapter 6, "Cloud Management Reference Architecture," covers frameworks in detail.
At this point, it is worth taking a few moments to discuss what exactly "IT value" is from a business perspective. Measuring value from IT investments has traditionally been an inexact science. The consequence is that many IT projects fail to fulfill their anticipated goals. Thus, many CIOs/CTOs today do not have much confidence in the accuracy of total cost of ownership (TCO), or more so, return on investment (ROI) modeling related to potential IT investments. A number of academic research projects with industry partnership have been conducted to look at better ways to approach this challenge.
One example would be the IT Capability Maturity Framework (IT-CMF), developed by the Innovation Value Institute (http://ivi.nuim.ie/ITCMF/index.shtml) along with Intel. Essentially, the IT-CMF provides a "capabilities maturity curve" (five levels of maturity) with a number of associated strategies aimed at delivering increasing IT value, thus ultimately supporting the business to maintain or grow sustainable differentiation in the marketplace.
The concept of capability maturity stems from the Software Engineering Institute (SEI), which originally developed what is known as the Capability Maturity Model Integration (CMMI). In addition to the aforementioned IT-CMF, organizations can use the CMMI to map where they stand with respect to the best-in-class offering in relation to defined IT processes within Control Objectives for Information and Related Technology (COBIT) or how-to best practice guides like ITIL (Information Technology Infrastructure Library provides best practice for IT service management). Chapter 4, "IT Services," covers COBIT in detail.