Conclusions

  We described how Eclipse/BSD applications can obtain resource reservations and thereby guarantee a desired quality of service for themselves or for their clients. Eclipse/BSD's API, /reserv, provides a simple, uniform interface to hierarchical proportional sharing of system resources. We discussed the different schedulers used in Eclipse/BSD and demonstrated experimentally that they can isolate the performance of selected applications from CPU, disk, or network overloads caused by other applications. Eclipse/BSD was implemented by making straightforward modifications to FreeBSD and greatly improves the system's ability to provide QoS guarantees, fairness, and hierarchical resource management. We believe that other common time-sharing systems would benefit from similar modifications.