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CHAPTER
19
Cloud
Management and a
Programming Model Case Study
C
loud computing does not imply any single technology. In short, a combination of multiple
methodologies defines its architecture. The management of various aspects associated with
this computing facility thus becomes very important case for successful outcome during its real-
life implementations.
Be it business delivery, or technical foundation of system development,
the ‘service’ takes center stage in cloud computing. Consequently, cloud service management
has become another important issue to be discussed in a new context.
Most management activities in cloud are automated and SLA-driven. The service level
agreement (SLA) thus plays an important role in the success of cloud computing. This chapter
represents the lifecycle of SLA, apart from discussing the lifecycle of cloud service. Cloud
management standards, tools and responsibilities of providers and consumers have also been
discussed.
This chapter also focuses on various programming models
which are implemented on
cloud. For this purpose a case study is represented with Aneka cloud platform which has a
special feature of supporting multiple programming models. In this context, the chapter tries
to revisit the cloud computing architecture once more and represents its design characteristics
and few non-functional features as well from different angles.
19.1 CLOUD ARCHITECTURE: REVISITED
In
very broad sense, the cloud computing system can be viewed as composition of two elements:
■
■
Client application at the front end
■
■
The
cloud as the back end.
This is a very simple description as the backend comprises of several layers and abstractions. In
most cases, the ‘client application’ at the
frontend is a web browser through which cloud service
interfaces (i.e. the portals) are accessed. Consumers can access the backend ‘cloud’ from any
simple electronic device capable of running web browsers. Only prerequisite
is the availability
of network or Internet service. Quality of cloud service accessibility often depends on the speed
of the network. But with advancements in the field of internet technology, speed is the least
worrying factor nowadays.
At the
backend, the ‘cloud’ resides at some remote location generally being managed by
some service providers. Reputed providers develop cloud service
infrastructure at their own
data centers. A provider can have multiple data centers at different geographic locations. As
shown in Figure 19.1, this backend part can be seen as composition of two broad components:
a cloud building platform and the cloud services. Cloud computing services (which attract the
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Cloud Computing
maximum interest of learners of this subject) are built over a stage that can be called as the
platform for cloud. This platform provides the supporting system for cloud operations.
The
platform for cloud computing operations is generally built
over large distributed
homogeneous/heterogeneous computing environments. This underlying layer provides the
support system on which different cloud computing facilities are developed to be delivered over
internetwork/Internet. Apart from computing devices, this layer (the platform for cloud) also
includes supporting facilities like the power supply system,
cooling system, physical security
of infrastructure and others. The host operating system (operating system that activates the
physical systems at data centers) and hypervisors stay at the top of this layer.
Cloud service layer mainly comprises of three categories of computing services as
infrastructure service, platform service and application service. Among three of these, the
infrastructure service is most interesting. Although, at data centers cloud
infrastructure services
are built using actual physical computing resources, consumers get access to these resources in
virtual form through IaaS facility.
Cloud architectures at data center can be portrayed as a combination of two layers: 1) the
underlying infrastructure for cloud service development, and 2) the layers of services developed
over the infrastructure.
