Chapter 13 - Cloud Computing Reference Architecture
One of the important things to decide when you discuss Cloud Service Strategy and Design is the consideration for a Reference Architecture. This is something that is useful to align to as it represents the blueprint for your cloud and make the implementation risk free. The Cloud Computing Reference Architecture (RA) is intended to be used as a blueprint / guide for architecting cloud implementations, driven by functional and non-functional requirements of the respective cloud implementation. The RA defines the basic building blocks - architectural elements and their relationships which make up the cloud. The RA also defines the basic principles which are fundamental for delivering & managing cloud services.
The reference architecture is more than just a collection of technologies and products. They consist of several architectural models and are much like a city plan. The RA defines how your cloud platform should be constructed so that it can satisfy not you’re your current demands and but also be extensible to support the future needs of a diverse user population. So this blueprint should be responsive to changing business and technology requirements and adaptable to emerging technologies. Existing “legacy” products and technologies as well as new cloud technologies can be mapped on the AOD to show integration points amongst the new cloud technologies and integration points between the cloud technologies and already existing ones. By delivering best practices in a standardized, methodical way, an RA ensures consistency and quality across development and delivery projects.
The IBM Cloud Computing RA is structured in a modular fashion with each functional capability (architectural elements), the user roles (that we discussed in Chapter 12) and their corresponding interactions. The IBM CCRA is created based on several cloud engagements and incorporates all the good practices and methods implemented across these projects. So for an end user adopting these good practices the risk and cost of implementation of their cloud will be low. The CC RA is built on the ELEG ( Efficiency, Lightweightness, Economies-of-scale, Genericity) principles.
One of the principles that I want to highlight here is the Genericity Principle – That’s the capability to define and manage generically along the Lifecycle of Cloud Services: Be generic across I/P/S/BPaaS & provide ‘exploitation’ mechanism to support various cloud services using a shared, common management platform (“Genericity”). As we know or discussed in the cloud delivery and deployment models (Chapter 3) there can many models for deployment and delivery of a Cloud Services. As we know Cloud Service can represent any type of (IT) capability which is provided by the Cloud Service Provider to Cloud Service Consumers - Infrastructure, Platform, Software or Business Process Services. The beauty and significance of the IBM Cloud Computing Reference Architecture is that it can cater to any of these service delivery and deployment models. So if you are building your private cloud or public cloud or using cloud to deliver IAAS, PAAS or SAAS the RA remains the same and handle all of these combinations. We have seen the capabilities that we need (Chapter 6) for implementing a common cloud management platform.
IBM has recently submitted the IBM Cloud Computing Reference Architecture 2.0 (CC RA) (.doc) to the Cloud Architecture Project of the Open Group, a document based on “real-world input from many cloud implementations across IBM” meant to provide guidelines for creating a cloud environment. Check out this link which has the interview with Heather Kreger, one of the authors of Cloud Computing Reference Architecture as well as the details of the components that make up the CCRA.
On the topic there is also an article that I found on syscon cloud computing journal which is comparing the Reference Architecture of the Big Three ( IBM, HP and Microsoft) which is an interesting read.
before we get into the details of the Service Implementation / Transition phase
it is important that we understand the bigger picture. The word document IBM
Cloud Computing Reference Architecture 2.0 (CC RA) (.doc) provides a great
description of this bigger picture and going into the details as required. The
architectural principles define the fundamental principles which need to be
followed when realizing a cloud across all implementation stages (architecture,
design, and implementation). This is a must read for all - development teams
implementing the cloud delivery & management capabilities as well as
practitioners implementing private clouds for customers.