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. Update: interview with Heather Kreger, one of the authors of Cloud Computing Reference Architecture.

CC RA emphasizes the synergies between cloud computing and SOA remarking that

The essential characteristics for Cloud Computing are on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured Service. These characteristics can be found in requirements and SOA solutions in various organizations today, although these characteristics are optional for SOA and mandatory for cloud.

CC RA outlines four architectural layers proposed to be used in cloud computing:

Operational Layer containing the basic cloud computing infrastructure

containing the basic cloud computing infrastructure Service Layer providing cloud services. IaaS is considered a service providing infrastructure along with PaaS offering middleware and SaaS providing applications.

providing cloud services. IaaS is considered a service providing infrastructure along with PaaS offering middleware and SaaS providing applications. Business Process Layer. IBM introduces a new type of service called BPaaS providing business processes as services similar to what SOA offers.

IBM introduces a new type of service called BPaaS providing business processes as services similar to what SOA offers. Consumer Layer. This is the layer consuming all the services generated by the previous layers.

According to CC RA, a high level view of a cloud environment looks like this:

CC RA continues by detailing each section of the diagram including the Common Cloud Management Platform (CCMP) which contains the largest number of components:

The CC RA is built on the ELEG ( Efficiency, Lightweightness, Economies-of-scale, Genericity) principles:

Design for Cloud-scale Efficiencies: When realizing cloud characteristics such as elasticity, self-service access, and flexible sourcing, the cloud design is strictly oriented to high cloud scale efficiencies and short time-to-delivery/time-to-change. (“Efficiency Principle”) Support Lean Service Management: The Common Cloud Management Platform fosters lean and lightweight service management policies, processes, and technologies. (“Lightweightness Principle”) Identify and Leverage Commonalities: All commonalities are identified and leveraged in cloud service design. (“Economies-of-scale principle”) 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”).

Update. Following is a short interview with Heather Kreger, one of the authors of Cloud Computing Reference Architecture.

InfoQ: Why did you make this reference architecture public? What do you hope to achieve? And why Open Group?

HK: Based on the experience IBM has in the design and deployment of cloud solutions, we wanted to offer the harvested architectural best practices we have accrued in the form of a reference architecture to the Open Group. This can serve as input for standardization process going on in the Cloud Architecture work group. We chose The Open Group because we really see the Open Group as having a center of gravity in architecture standards. They have TOGAF, which has been successful, and that attracts a lot of high quality architects to the standards work there. In combination with the other cloud standards being developed there, The Open Group has the right people, momentum and expertise to develop and continue care and feeding of a reference architecture like the CCRA.

InfoQ: IBM has endorsed the OpenCloud Manifesto. What is your position regarding OpenStack , considering they are trying to create a cloud computing reference implementation?

HK: We understood that OpenStack was creating an implementation but doesn't seem connected to existing standards work. We'd love for them to come participate in the Open Group Cloud Architecture development work.

InfoQ: Are you using the Reference Architecture internally at IBM?

HK: Yes, the CC RA is used within IBM for multiple purposes, first, as the blueprint for cloud implementations our field practitioners architect, design & implement for customers. This is actually the second version in IBM, we've updated it based on our extensive experience with SOA and Cloud implementations in the industry.

Second, we are also using it with our IBM-hosted clouds that we use for internally as well as the ones we offer externally to customers. We've learned a lot and will continue to iterate with our experience with The Open Group. We think this "closed loop" is very important given the quickly evolving cloud space.

InfoQ: Are there companies using your Reference Architecture for building cloud infrastructure?

HK: Yes, those we've been doing services engagements with, and those who are using our IBM hosted cloud services.

InfoQ: Are there companies using the RA to create and consume services in IBM's cloud computing environment?