Putting the User in Direct Control of CPU Scheduling
Binshan Lin, Peter A. Dinda · 2006
CPU scheduling to enforce service-level agreements (SLAs) is a problem of key importance in service-oriented systems. For services whose ultimate customers are naive end-users, it is often a significant challenge simply to determine the terms of the SLA. We propose a new approach to both SLA specification and scheduling for enforcement that is unique in that it is based around the use of direct user input. Our implementation of the idea is designed for virtual machine (VM)-based computing environments. In our system, a user's VM is scheduled as a periodic real-time task. The user can instantaneously manipulate his VM's schedule using a joystick. An on-screen display illustrates the current schedule's cost and indicates when the user's desired schedule is impossible due to the schedules of other VMs or resource constraints. An extensive user study of the system indicates that even a naive user is capable of using the interface to our system to find a schedule that balances cost and the comfort of his VM. Good schedules are user- and application-dependent to a large extent, illustrating the benefits of user involvement.