Book Excerpt: “Fundamental Cloud Architectures”

Grazed from Sys Con Media.  Author: Thomas Erl, Ricardo Puttini, Zaigham Mahmood.

"The sample chapter below is from the book, ‘Cloud Computing: Concepts, Technology & Architecture’ authored by Thomas Erl with Zaigham Mahmood and Ricardo Puttini, published by Pearson/Prentice Hall Professional, May 2013, ISBN 0133387526, Copyright 2013 Arcitura Education Inc. For more info please visit: http://www.informit.com/store/cloud-computing-concepts-technology-architecture-9780133387520"

This chapter introduces and describes several of the more common foundational cloud architectural models, each exemplifying a common usage and characteristic of contemporary cloud-based environments. The involvement and importance of different combinations of cloud computing mechanisms in relation to these architectures are explored…

Workload Distribution Architecture
IT resources can be horizontally scaled via the addition of one or more identical IT resources, and a load balancer that provides runtime logic capable of evenly distributing the workload among the available IT resources (Figure 1). The resulting workload distribution architecture reduces both IT resource over-utilization and under-utilization to an extent dependent upon the sophistication of the load balancing algorithms and runtime logic.

Figure 1: A redundant copy of Cloud Service A is implemented on Virtual Server B. The load balancer intercepts cloud service consumer requests and directs them to both Virtual Servers A and B to ensure even workload distribution.

This fundamental architectural model can be applied to any IT resource, with workload distribution commonly carried out in support of distributed virtual servers, cloud storage devices, and cloud services. Load balancing systems applied to specific IT resources usually produce specialized variations of this architecture that incorporate aspects of load balancing, such as:…

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