QoS-Oriented Service Computing - Advanced Design Approaches to Emerging Software Systems - page 292

Figure 5. Hunter game, where if a given number of player reaches maximum limit, the capacity will
extend seamlessly for the player to fit with that number. The QoS-oriented service computing is employed
and the scalability is realized by on-demand resource provisioning via zone migration

number of players reaches the maximum limit, the
map will extend seamlessly for the player to fit
with that number. This scalability means that the
game can potentially host hundreds of players on
the same map, along with providing players with
a brand new experience online.
This scalability feature is realised through the
on-demand resource provisioning via zone migra-
tion. A test case scenario is described as follows,
as shown in Figure 6: As currently the widely
used architecture for online games is the multi-
client and multi-server mode of the client/server
architecture (Bartle et al., 2003; Cai et al., 2002;
Rosedale et al., 2003), where it consists of a set
of servers that are concurrently accessed by a
number of users that dynamically interact with
each other within a game session, we deploy the
Hunter game on two Hosters, namely, ' hoster1 '

and ' hoster2 '. Each Hoster is an individual infra-
structure provider which delivers a platform
presented as a collection of Web services required
for running Hunter (e.g. Mgt. Layer, HMI), QoS
assurance (e.g. SLA), and invoicing mission (e.g.
Trade account service). Therefore each Hoster
can be regarded as a single Cloud provider and
they together formulate a service-oriented infra-
structure of federated Cloud computing for on-
demand resource provisioning. We also have a
global session service running at the Coordinator
side, which creates one global session ' gSession1 '.
Two local sessions ' local session 1 ' and ' local
session 2 ' are created at each Hoster and partici-
pate the global session 'gSession1'. A ' zone0 ' is
created and attached to ' local session 1 '.
There are 5 authorized customers participated
to ' zone0 ' to start the use of ROIA application