PolyStore: Exploiting Combined Capabilities of Heterogeneous Storage

With the "non-hierarchical" trend in emerging storage media, the philosophy of hierarchy inevitably falls short in fully leveraging the combined bandwidth of multiple devices. In this paper, we propose a horizontally structured storage architecture that leverages the combined capabilities of heterogeneous devices. We introduce PolyStore, a meta layer atop storage medium-optimized file systems that spans userspace and the OS, allowing applications to access multiple storage devices concurrently with transparent, fine-grained data placement. PolyStore maximizes cumulative storage bandwidth and reduces hardware and software bottlenecks without compromising important properties such as sharing and security. Our evaluations show that PolyStore achieves 1.11X- 9.38X performance gains for micro-benchmarks and 1.52X- 2.02X for real-world applications across various device configurations.