QoS-Oriented Service Computing - Advanced Design Approaches to Emerging Software Systems - page 290

monitoring data will be available to the external,
e.g. via web service interfaces.
The ISONI should be able to automatically
deploy and instantiate the service. In order to
facilitate this, ISONI introduces an abstract de-
scription of all the execution environment require-
ments of the service, including the description
of the interconnections and their individual QoS
demands, namely, Virtual Service Network (VSN).
This VSN description needs to be delivered by
the service developer. Each VSN maps to one or
more Virtual Machine Unit (VMU). The VSN
description is transferred to the ISONI with the
request to instantiate the service. The ISONI then:

Currently ROIA-alike applications (e.g. on-line
game) are hosted statically, which is independent
from the actual user demand. This static hosting
strategy can lead to significant over consumption
of resources on average (and hence increased
costs), yet may be unable to match peak demand
on occasion, leading to customer dissatisfaction.
On the other hand, Grid-based hosting has the
potential to tackle these problems by allowing
resources to be provisioned on-demand to match
the dynamically changing user loads.
In order to accommodate these needs, the
Edutain business model (as shown in Figure 4)
introduces a concept, namely ROIA Coordinator
to help realize the on-demand resource provision-
ing for ROIA application from the scalability
and performance perspective. Coordinator can
be regarded as an organization that plays a role
of ROIA application service provider (e.g. online
game). However, the Coordinator itself does not
have any physical infrastructure for running ROIA,
instead it outsources the ROIA hosting services
to Hoster, which is an organization that dedicates
to host core, usually computationally intensive
processes that support a ROIA running environ-
ment. The Hoster plays a role of infrastructure
provider. The Coordinator provides an integrated
user frontend (e.g. portal) to make ROIA instances
accessible to consumers. In order to get access
to the ROIA instance, a customer need open an
account with Coordinator to obtain a Security
Assertions Markup Language (SAML) token,
and then use this SAML token to get connection
details of associated ROIA instances.
In this Coordinator-Hoster business model for
ROIA applications, the ROIA hosting platform
and ROIA application are delivered by Hosters
as services to the Coordinator. The Coordinator
has an account and a bipartite Service Level
Agreement (SLA) with Hoster. The Hoster pro-
vides metered services to the Coordinator. When
the hosting service finishes, the Hoster sends the
bill to the Coordinator for the resource usage. This

• Automatically and autonomously maps the

highly abstracted resource request in form
of the VSN description onto the network of
real resources

• Deploys the components in tailored execu-

tion environments on suitable resources

• Interconnects them while observing QoS

requirements

CASE STUDY: QOS-ORIENTED
SERVICE COMPUITNG
IN EDUTAIN@GRID

This case study demonstrates how QoS-oriented
service computing is employed in Edutain@
Grid project to facilitate the on-demand resource
provisioning.

Edutain@Grid: Cloud
Computing Vision

When the Edutain project was sponsored there
was no term called “Cloud computing”. But the
Edutain project inherently encompasses many
concepts/ideas that Cloud computing is promoting
(e.g. HaaS/SaaS, utility computing, on-demand
resource provisioning), and many of which have
been implemented and demonstrated for ROIA.