Hierarchical, adaptive cache consistency in a page server OODBMS

Due to its simplicity and communication efficiency, many client-server object-oriented database systems are based on the basic page server architecture - pages serve as their smallest unit of data transfer; client caching, and concurrency control, In an earlier paper we showed how to extend this architecture to permit object-level callback locking, and we showed through simulations that significant performance gains can be expected. In the current paper we report on our experiences from implementing this approach in the context of the SHORE system, which supports a generalized peer-servers architecture. In addition to discussing some of the stickier implementation details, we also explain how our callback algorithm was extended to support the hierarchical locking approach used in SHORE. Finally, we present performance measurements obtained by running SNORE on an IBM SP2 machine.