Motivating example and problem analysis - Reliability Assurance of Big Data in the Cloud - page 29

• Third, according to the previous problem analysis, it can be seen that the data reliability as-
surance mechanism is the core of the whole solution. Therefore, it needs to be designed to
be able to coordinate with the data creation and data recovery processes effectively.
Only after all the three challenges of the mechanism are solved, the goal of cost-
effective data storage and data reliability assurance can be achieved.
3.2.4.4 Cost-effective data transfer strategy for data creation
and data recovery
To transfer the big data in the Cloud in a cost-effective fashion, the overhead, that is,
the energy consumption incurred during the data transfer process, needs to be reduced.
Such optimization could benefit our data storage solution in both the data creation
stage and the data recovery stage. According to the analysis in Section 3.2 for Cloud
network characteristics and data transfer activities in the Cloud, there are two other
issues that also need to be fully considered during the design of the data transfer
strategy.
• First, for data transfer in the Cloud, the time constraint of data transfer tasks (i.e., the data
transfer deadline) must not be jeopardized so as to suit the high demand of time accuracy in
a dedicated Cloud network as well as ensure that the data reliability requirement of Cloud
data can always be met.
• Second, due to the “lazy” nature of data transfer for maintaining the Cloud data, our optimi-
zation focuses on the lazy data transfer type to reduce the data transfer energy consumption.
Meanwhile, negative impact of the optimization toward other types of data transfer activities
should be avoided. For example, the maximum speed data transfer requirement of eager data
transfer should not be jeopardized, and the existing link traffic should not be affected.
3.3 Summary
In this chapter, we presented the motivating example of our research and analyzed
characteristics of the motivating example, the Cloud storage and the Cloud network re-
spectively to further illustrate the details of our research issues. Based on the problem
analysis in this chapter, our cost-effective data storage and data reliability assurance
issues are finally identified. In the rest of the topic, the solutions for four research is-
sues identified will be presented one by one from Chapter 4 to Chapter 7 respectively.