A Two-Tiered Software Architecture for Automated Tuning of Disk Layouts (CMU-CS-03-130) SalmonBrandon ThereskaEno SoulesCraig A.N. GangerGregory R. 2003 Many heuristics have been developed for adapting on-disk data layouts to expected and observed workload characteristics. This paper describes a two-tiered software architecture for cleanly and extensibly combining such heuristics. In this architecture, each heuristic is implemented independently and an adaptive combiner merges their suggestions based on how well they work in the given environment. The result is a simpler and more robust system for automated tuning of disk layouts, and a useful blueprint for other complex tuning problems such as cache management, scheduling, data migration, and so forth.