Why It Is Hard to Build a Long-Running Service on PlanetLab

PlanetLab was conceived as both an experimental testbed and a platform for long-running services. It has been quite successful at the former, less so at the latter. In this paper we examine why. The crux of the problem is that there are few incentives for researchers to develop long-running services. Research prototypes fulfill publishing requirements, whereas long-running services do not. Several groups have tried to deploy research services, long-running services that are useful, but also novel enough to be published. These services have been generally unsuccessful. In this paper we discuss the difficulties in developing a research service, our experiences in developing a research service called Stork, and offer suggestions on how to increase the incentives for researchers to develop research services.