Exo-leasing: escrow synchronization for mobile clients of commodity storage servers
Liuba Shrira, Hong Tian, Doug Terry · 2008
Abstract. Escrow reservations is a well-known synchronization tech-nique, useful for inventory control, that avoids conflicts by taking into account the semantics of fragmentable object types. Unfortunately, cur-rent escrow techniques cannot be used on generic “commodity ” servers because they require the servers to run the type-specific synchronization code. This is a severe limitation for systems that require application-specific synchronization but need to rely on generic components. Our exo-leasing method provides a new way to implement escrow syn-chronization without running any type-specific code in the servers. In-stead, escrow synchronization code runs in the client providing the abil-ity to use commodity servers. Running synchronization code in the client provides an additional benefit. Unlike any other system, our system al-lows a disconnected client to obtain escrow reservation from another disconnected client, reducing the need to coordinate with the servers. Measurements of a prototype indicate that our approach provides escrow-based conflict avoidance at moderate performance overhead. 1