Cloud Computing Fundamentals
In this chapter, we introduce the fundamentals required for the understanding of the following chapters. As stated in the introduction, the cloud computing properties – access via network, on-demand self-service, measured service (pay-per-use), resource p
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Cloud Computing Fundamentals
Fig. 2.1 Pattern map of cloud computing fundamentals
In this chapter, we introduce the fundamentals required for the understanding of the following chapters. As stated in the introduction, the cloud computing properties – access via network, on-demand self-service, measured service (pay-per-use), resource pooling and rapid elasticity – fundamentally change how IT resources are provided and used. It is important to understand why cloud offerings have these properties, how these properties are delivered on different levels of a typical application stack and under which conditions an application benefits from them. We begin by examining application workloads (Sect. 2.2) and show how they influence the decision for the adoption of cloud offerings. Especially, we discuss how applications experiencing different types of workloads can benefit from the cloud computing properties covered in Chap. 1. As in that previous chapter, we use All figures published with kind permission of # The Authors 2014. See list of figures. C. Fehling et al., Cloud Computing Patterns, DOI 10.1007/978-3-7091-1568-8_2, # Springer-Verlag Wien 2014
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Cloud Computing Fundamentals
the NIST cloud definition [3] and emphasis on those aspects that are important to understand the following chapters. Having motivated the need for cloud offerings to handle different workloads we introduce common cloud service models (Sect. 2.3) that describe different styles to offer IT resources on different levels of an application stack. We cover the layers of this application stack and their function in an application. Furthermore, we discuss how the corresponding service models Infrastructure as a Service, Platform as a Service and Software as a Service enable the cloud computing properties. In the last section of this chapter, we introduce the cloud deployment models (Sect. 2.4) and describe how they differ regarding the sharing of IT resources, reaction to varying application workloads, economies of scale, and costs. These properties significantly affect cloud adoption in companies influenced by the concern that outsourcing parts of an application stack and sharing IT resources with other companies can negatively impact privacy and security of data and processes. Side Note: the patterns in this chapter differ from other patterns in this book. They are not implemented by developers, but characterize the context in which other patterns are applicable. We used the pattern format to correlate them with other patterns in a uniform way and use their icons to characterize cloud environments and application requirements in Chap. 7.
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Overview of Fundamental Cloud Computing Patterns
As seen in Fig. 2.1, the map of patterns covered in this chapter for application workloads, cloud deployment types, and cloud service models are strong interconnected. While this is not the case for most of the other patterns in this book, these fundamental patterns form the basis for the understanding of the remaining patterns and should always be
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