Information Technology Reference
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Performance requirement is constrained by performance-related restric-
tion. Latency performance is constrained by latency restriction (expressed
via hasLatency property). Bandwidth performance is constrained by band-
width restriction . Bandwidth restriction indicates minimum amount of
bandwidth required using the hasMinBandwidth property.
Resource requirement is constrained by resource-related restriction. Host-
ing environment is constrained by operating system restriction which indi-
cates the operating system types (via hasOS property). Hardware capability
is constrained by hardware restrictions ,suchas cpu core restriction (via
hasMinCPUCore property), cpu speed restriction (via hasMinCPUS-
peed property), cpu architecture restrictioin (via hasCPUArchitecture
property), RAM restriction (via hasMinMemory property), and storage
space restriction (via hasMinStorageSpace property). Software stack is
constrained by software restriction which indicates the list of softwares or
services that need to be installed on the resource (via hasSoftware property).
Geographical requirement is constrained by location restriction . Lo-
cation restriction is associated with hasLocation property that indicates the
location (country or data center location).
Compliancecoderequirement is constrained by compliance restric-
tion ,whichcanbe standard code restriction - contains the standard's code
format or regulatory restriction - contains the name of regulation.
3.3 Resource Ontology
The resource ontology, the bottom layer of the proposed model, defines the
properties of the resources offered by cloud providers. This layer has been widely
investigated elsewhere - see [2] and [8]. These existing ontologies can be applied
as the resource ontology in the proposed model. The mapping of infrastructure
requirements to the resource ontology can be achieved by using query language
[5] - this topic is outside the scope of this paper.
4 Translation from Domain-Specific Ontology
Here consideration is given as to how a domain-specific ontology can be trans-
lated to the infrastructure requirements ontology.
For the media transcoding example, application developers need to provision
an infrastructure which fulfils the transcoding requirements as well as balances
the budget and delivery time constraints. Transcoding requirements, such as
video format conversion, frame rate conversion or http streaming, indicate the
features or capabilities of a transcoding software that need to provide. Particular
software, such as FFmpeg or Rhozet, can be used to perform the transcoding
task. However, each software has different system requirements. For example,
Rhozet must be run on Windows operating system, whereas FFmpeg can be
run on Linux. Using the proposed multi-layer ontology model, domain-specific
transcoding requirements can be translated into software requirements, where
 
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