Global Snapshot File Tracker

Abstract

Desktop clouds offer cloud computing services on desktops, simultaneously with users in interactive sessions. Users can affect the virtual machines execution for several reasons. For example, a user can turn-off or reboot the physical machine, or a user can execute demanding applications. A global snapshot of a distributed system is a fault tolerance strategy. In a previous work, we developed the Desktop Cloud Global Snapshot, which obtains the state of the whole system. In case of failure, it is possible to go back to the stored state and resume execution from that point. To recover the system from a global snapshot, we can use the same physical machines or others, if necessary. For this solution it is essential to have a file management system. As global snapshots are created, the number of files that must be handled grows making their management more complex. This article presents the Global Snapshot File Tracker, a software tool that is responsible for maintaining the record of the files that form the state of each virtual machine from its snapshots, and determining what files are required to replicate the state of the virtual machine if it is necessary to resume its execution on another host. The paper includes the background, the problem statement, the proposed solution, the developed solution, and the functionality and evaluation.