M.Sc Thesis

M.Sc StudentKutiel Gilad
SubjectCost-Aware Live Migration of Services in the Cloud
DepartmentDepartment of Computer Science
Supervisors PROF. Dan Raz
DR. David Brietgand


Live migration of virtual machines is an important component of the emerging cloud computing paradigm.

While live migration provides extreme versatility of management, it comes at a price of degraded service performance during migration.

The bulk of studies devoted to live migration of virtual machines focus on the duration of the copy phase as a primary metric of migration performance.

Clearly, short down time is desirable, however, the pre-copy phase imposes an overhead on the infrastructure that may result in severe performance degradation of the migrated and collocated services. This may result in offsetting the benefits accrued through live migration.

We observe that there is a non-trivial trade-off between minimizing the copy phase duration and maintaining an acceptable quality of service during the pre-copy phase, and introduce a new model to quantify this trade-off. We then show that using our model, an optimal migration schedule can be efficiently calculated. Finally, we simulate, using real traces, live migrations of a virtual machine running a web server and compare the migration cost obtained using our algorithm and commonly used live-migration methods.