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One of the salient features of globally distributed, on-demand
computing infrastructure is that it can easily shift resources
geographically close to where the demand is coming from. Intuitively,
it makes sense that a predictable, diurnal pattern drives global
resource consumption and hence, the provisioning of server resources.
This is especially the case for applications that require human
participants such as games. To study this phenomenon, we examined a
one-week period of cs.mshmro.com (Sunday May 23, 2004 to
Saturday May 29, 2004). Using this log and a commercial geographic IP
address mapping tool [31], the location of each player
connecting was resolved. As Table 4 shows, a
significant portion of the load is from outside of North America.
Using the resolved connections, the per-continent load normalized by
the mean connection arrival rate was plotted. As
Figure 13 shows, each continent shows a
predictable, diurnal pattern of activity with the only difference
being a time-zone shift. It is interesting to note that in contrast
to the Half-Life aggregate load and international beverage company web
site load (Figure 12(c)), the per-continent load
of cs.mshmro.com exhibits a large variance similar to the
North American web site loads shown in Figures 12(a)
and 12(b). We hypothesize that when the usage patterns
of international services are broken out into individual
regions, the resulting load variances are similar to those of regional
servers such as the cereal manufacturer and the credit card company.
To test this hypothesis,
we compared the per-continent load
between cs.mshmro.com and the international beverage company
web server trace .
Figure 14 shows the per-continent, normalized
load of the game and web server for North America and Europe.
The loads from other continents show similar results.
As expected, the per-continent load fluctuations and variance
are similar to those found in the two regional web sites.
The figure also shows that usage of both applications
are highly synchronized when broken down into geographic regions.
The degree of synchronization thus
limits the benefits that geographically distributed, on-demand computing infrastructure has on
interactive applications such as games and web.
Next: Game updates significantly impact
Up: Potential for multiplexing gain
Previous: Games and interactive application
2005-08-10