Dissertaç ˜ao de Mestrado Mestrado em Engenharia Informática Jo ...

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State of the Art and Related Work
This section aims at presenting the state of the art in automatic application configuration, as
well as studying the tools which may be used to tackle the problem identified in Chapter 1.
To better understand the outlines of the problem, this section starts by explaining the con-
text of this dissertation. Namely, the virtual appliances theme is explored with the purpose of
making it more natural.
Afterwards, the existing techniques to deal with the problem are analysed. There is, never-
theless, a particularity regarding this part. As previsouly mentioned in Chapter 1, the configu-
ration of applications is still mostly a manual task. As such, the existing references considerably
relevant to this theme are very few. Therefore, this dissertation consists on one of the first con-
tributions for the problem of automatic configuration of applications.
Finally, the adopted concepts and tools to mitigate the problem are analysed. The automatic
file recognition theme is studied by identifying two parser generators and describing them.
Finally, it is seen how the file can be represented in an abstract, independent from its original
language, way.
2.1 Virtual Appliances
A Virtual Appliance (VA) is a minimal virtual machine (VM, Section 2.1.1) composed of pre-
configured and pre-installed applications plus an optimized operating system called Just
Enough Operating System (JeOS) (Figure 2.1). VAs are normally created to perform a specific
task in the most effective way, therefore they only contain the essential and necessary resources
for the execution of that task, contrary to the regular VM where all of the kernel OS features are
present, even those whose use is seldom.
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