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5 CASE STUDY:
A UNIVERSITY CONTENT
MANAGEMENT SYSTEM
In this section, the costs of deployment options are
compared for the case of university content
management system based on Plone.
In this case, the “own” deployment assumes the
acquisition of a Dell PowerEdge M610 server, and
installing a stack of open-software on it, including
Zope WWW-application server, Zope Object
Database, Zope Enterprise Objects, Plone content
management system, etc. (Ojaniemi 2010). The costs
of hardware acquisition are estimated based on the
price of the server as €4102. The current outbound
data transfer volume is estimated at the order of
1TB/month, which, assuming the price of $0.11
(€0.078) per GB, corresponds to the costs of €80.
In future, with the increased proliferation of
online teaching content, the data transfer volume
may increase dramatically by the factor of 100, thus
reaching 100TB/month and resulting in the monthly
data transfer costs of €8023. On the other hand, in a
hypothetical case of shifting the content
provisioning to individual departments’
infrastructure, the data volume of the university
content management system may be decreased
tenfold to 0.1TB/month, resulting in the data transfer
costs of €8/month.
In the “cloud” deployment scenario, the
computing requirements of the current service are
assumed to be met by EC2 extra large instance. With
the Amazon pricing, the data transfer costs for the
current load are €109.4/month; in case of the
increase to 100TB/month, the data transfer cost will
rise to €7720.5/month; in case of the downscaling to
0.1TB/month, the cost will drop to €10,9/month.
When the load increases by the factor of , the
number of requests to the server(s) is also going to
increase, but at a smaller pace, e.g. the by the factor
of
√
– reflecting the assumption that the increase in
load due to new type of content rather than new
students. Then, the increased load would need to be
served by
√
in-house servers (“own” deployment)
or by
√
extra large instances (“cloud” deployment).
Based on Amazon pricing, the computing costs
for the current service in “cloud” deployment
comprise €222/month. For the increased load, the
costs would rise to €2218. For the decreased load,
the smaller computing power is required; assuming
that the Amazon Large instance is sufficient, the
monthly computing costs would decrease to
€111/month.
For “own” deployment, the maintenance costs
for the acquitted hardware are assumed to be 20% of
the acquisition price. The other costs (including the
costs of storage needed) are either assumed equal for
both alternatives, or are assumed negligible.
The resulting costs are summarized in the table
below, and the computing, bandwidth, and total
costs accumulated over 3 years are visualized in
Figure 2. As could be seen from the table, as soon as
the data transfer costs represent the major cost
constituent (which is the case with the increased data
transfer), the “cloud” deployment option is less
expensive than the “own” deployment. Furthermore,
according to the discussion in the previous section,
the cost of “mixed” scenario will be greater than the
“cloud” deployment’s costs in this case.
For the case with the current and the decreased
data transfer, the contribution of the data transfer to
the total costs is more significant. As a consequence,
the result of the comparison is different: the “cloud”
deployment option is more expensive. Primarily, this
is due to the high costs of Amazon instances.
6 CONCLUSIONS
In this paper, a quantitative model for assessing the
total costs of alternative software deployment
options has been introduced, whereby the costs of
Table 3: Costs of the university management system.
Costs Current data transfer Increased data transfer Decreased data transfer
“Own” “Cloud” “Own” “Cloud” “Own” “Cloud”
Acquisitions 4 102,9 € 0,0 € 41 028,6 € 0,0 € 1 296,5 € 0,0 €
Computing 820,6 € 2 661,3 € 8 205,7 € 26 613,5 € 259,3 € 1 330,7 €
Data transfer 962,7 € 1 312,8 € 96 273,5 € 86 646,2 € 96,3 € 131,3 €
Total 1st year 5 886,2 € 3 974,2 € 145 507,8 € 113 259,6 € 1 652,1 € 1 462,0 €
Total 2nd year 7 669,5 € 7 948,3 € 249 987,0 € 226 519,3 € 2 007,7 € 2 923,9 €
Total computing 6 564,6 € 7 984,0 € 65 645,8 € 79 840,5 € 2 074,5 € 3 992,0 €
Total data transf. 2 888,2 € 3 938,5 € 288 820,5 € 259 938,5 € 288,8 € 393,8 €
Total 3rd year 9 452,8 € 11 922,5 € 354 466,3 € 339 778,9 € 2 363,3 € 4 385,9 €
CLOSER 2011 - International Conference on Cloud Computing and Services Science
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