Toast Lab has one technical paper accepted by the 35th ACM International Symposium on High-Performance Parallel and Distributed Computing (HPDC 2026). It is titled "Pome: Parallelizing I/Os and Computations for Efficient LSM-tree-based Data Storage". It was solely done by Toast Labmates. Mr HU Yanpeng and Ms ZHU Li have contributed equally to the paper. Mr JIA Lei is a co-author. Chundong is the corresponding author.
CPU computations and I/O operations are fundamental to data storage systems. Storage systems conduct computations with their user threads, such as sorting data for orderliness. They handle I/Os mainly through system calls (syscalls) including file write, read, and fsync, which the OS’s kernel threads perform with storage devices. Today, LSM-tree-based storage systems are widely deployed in production environments. Compaction is an essential operation that LSM-tree employs to maintain its tiered tree-like structure by re-sorting and re-storing data through computations and I/Os,respectively. In this paper, we first overhaul the procedure of a compaction. We find that computations and I/Os execute in sequential order. After re-sorting data, the user thread waits for a kernel thread to complete file write and fsync I/Os. These costly synchronous I/Os create a severely long critical path that affects the performance of LSM-tree. To address this issue, we propose parallelizing I/Os and computations for efficient LSM-tree-based data storage (Pome). Pome decouples computations from I/Os within each compaction by referring to its new protocol that moves I/O operations out of the critical path. To this end, it leverages the io_uring to perform asynchronous I/Os. Furthermore, regarding the potential I/O congestion caused by accelerated compactions, Pome incorporates an adaptive I/O rate limiter to achieve smooth execution. We prototype Pome on top of RocksDB. Experimental results demonstrate that Pome significantly improves the performance of RocksDB and outperforms several state-of-the-art LSM-tree variants.
This year, HPDC received 281 submissions and accepted 41 papers for the technical program and 28 for poster presentations, for an acceptance rate of just over 14% for technical papers. It will convene in Cleverland, Ohio, USA during 13-16, 2026.