Scalable high-level caching for parallel I/O

Summary form only given. In order for I/O systems to achieve high performance in a parallel environment, they must either sacrifice client-side file caching, or keep caching and deal with complex coherency issues. The most common technique for dealing with cache coherency in multiclient file caching environments uses file locks to bypass the client-side cache. Aside from effectively disabling cache usage, file locking is sometimes unavailable on larger systems. The high-level abstraction layer of MPI allows us to tackle cache coherency with additional information and coordination without using file locks. By approaching the cache coherency issue further up, the underlying I/O accesses can be modified in such a way as to ensure access to coherent data while satisfying the user's I/O request. We can effectively exploit the benefits of a file system's client-side cache while minimizing its management costs.