​​​Welcome to another edition of South Bay Systems! This time we bring you two wonderful talks from authors at the just-finishing Conference on File and Storage Technologies (FAST '26):

• ​​Xinjun Yang will present his work on PolarStore, the new compression in PolarDB.

• ​​Ilya Meignan--Masson will present his work uCache, a unikernel-based I/O cache.

​​Agenda

• ​​​​​​6:00 PM: Doors open, food and socializing

• ​​​​​​6:30 PM — 6:50 PM: PolarStore Talk

• ​​6:50 PM — 7:10 PM: uCache Talk

• ​​​​​​7:10 PM onward : Community socializing!

​​​​​​Food and beverages will be provided, courtesy of our hosts, Everpure.

​PolarStore: High-Performance Data Compression for Large-Scale Cloud-Native Databases

​PolarStore is a compressed shared storage system for cloud-native RDBMSs. PolarStore employs a dual-layer compression mechanism that combines in-storage compression in PolarCSD hardware with lightweight compression in software. This design leverages the strengths of both approaches. PolarStore also incorporates database-oriented optimizations to maintain high performance on critical I/O paths. Drawing from large-scale deployment experiences, we also introduce hardware improvements for PolarCSD to ensure host-level stability and propose a compression-aware scheduling scheme to improve cluster-level space efficiency. PolarStore is currently deployed on thousands of storage servers within PolarDB, managing over 100 PB of data. It achieves a compression ratio of 3.55 and reduces storage costs by approximately 60%, and these savings are achieved while maintaining performance comparable to uncompressed clusters

​Speaker Bio

​Xinjun (Jimmy) Yang is the Senior Director of PolarDB, Database Group, Alibaba Cloud. Leading developing one of the fastest growing databases in Asia Pacific. His recent work won the 2024 and 2025 Best Industry Paper Award on ACM SIGMOD conference, one of the most prestigious and premier conferences for database researchers, engineers, and practitioners. Before joining Alibaba, he worked as InnoDB Architect in Oracle MySQL Team and earlier as a DBAcess group manager in the Sybase Enterprise Server Team.

​uCache: A Customizable Unikernel-based IO Cache

​Modern storage hardware like NVMe SSDs has outpaced the traditional OS storage stack, leaving developers with a dilemma: stick with simple but slow OS-level caching (mmap), or design complex, custom userspace solutions. In this talk, I will introduce uCache, a novel IO caching architecture that eliminates this trade-off. By leveraging a unikernel-based design, uCache bridges the gap between userspace and in-kernel approaches, enabling efficient and scalable operations that can be customized to the application workload. In particular, unlike kernel-bypass approaches that often require implementing custom storage stacks, uCache's integration into the OS enables it to leverage existing, robust filesystem implementations for file management while optimizing the data path for NVMe performance.

​Speaker Bio

​Ilya is a 3rd year PhD candidate at the Technical University of Munich. His research interest lies in the design of specialized operating systems that leverage application semantics to improve performance and resource utilization of data-intensive applications. He will be looking for an internship in the industry or for visiting another research group in academia in the coming year.