A Software Transactional Memory Service for Grids

In-memory data sharing for grids allow location-transparent access to data stored in volatile memory. Existing Grid middlewares typically support only explicit data transfer between Grid nodes. We believe that Grid systems benefit from complementing traditional messagepassing techniques with a data-oriented sharing technique. The latter includes automatic replica management, data consistency, and locationtransparent access. As a proof of concept, we are implementing a POSIXcompatible object sharing service as part of the EU-funded XtreemOS project, which builds a Linux-based Grid operating system. In this paper we describe the software architecture of the object sharing service and design decisions including transactional consistency and peer-to-peer network structure. We also present preliminary evaluation results analyzing lower-bound transaction-overhead using a parallel raytracing application.