Abstract: Low Earth Orbit (LEO) satellites are an important facet of global connectivity providing high speed Internet, cellular, IoT connectivity and so on. Combined with the rich resource availability on each satellite, LEO satellites represent a new, emerging cloud frontier – the LEO Compute Cloud. However, satellite mobility introduces non-trivial challenges when orchestrating applications for a LEO compute cloud, making it harder to deploy applications without increasing the latency and bandwidth costs. In this paper, we identify the concrete challenges in using state-of-the-art terrestrial orchestrators for a LEO compute cloud. We present Krios – a LEO compute cloud orchestration system that hides the complexities introduced by satellite mobility and enables a practical LEO compute cloud. The design of Krios is centered around a novel LEO zones abstraction that allows application providers to specify where their applications should be available. Krios provides crucial system support to enable the LEO zones abstraction, ensuring uninterrupted availability of applications in LEO zones via proactive and predictive application handovers. Our experimental evaluation of Krios with representative applications demonstrates a practical and efficient LEO compute cloud, without requiring any disruptive changes in applications and with modest system overheads. With Krios, LEO orchestration requires just ~1 application instance at a time to maintain the same availability as what prior work achieves by deploying application instances on all satellites or by performing 6-10 times more frequent expensive handovers.
See the published article here.