Fine-Grained Policy-Driven I/O Sharing for Burst Buffers

• Published in: SC23: International Conference for High Performance Computing, Networking, Storage and Analysis pp. 1 - 12
• Main Authors: Karrels, Ed, Huang, Lei, Kan, Yuhong, Arora, Ishank, Wang, Yinzhi, Katz, Daniel S., Gropp, William D., Zhang, Zhao
• Format: Conference Proceeding
• Language: English
• Published: ACM 11.11.2023
• Subjects: Benchmark testing; Bridges; File systems; High performance computing; Interference; Supercomputers; Throughput
• ISSN: 2167-4337
• DOI: 10.1145/3581784.3607041

A burst buffer is a common method to bridge the performance gap between the I/O needs of modern supercomputing applications and the performance of the shared file system on large-scale supercomputers. However, existing I/O sharing methods require resource isolation, offline profiling, or repeated execution that significantly limit the utilization and applicability of these systems. Here we present ThemisIO, a policy-driven I/O sharing framework for a remote-shared burst buffer: a dedicated group of I/O nodes, each with a local storage device. ThemisIO preserves high utilization by implementing opportunity fairness so that it can reallocate unused I/O resources to other applications. ThemisIO accurately and efficiently allocates I/O cycles among applications, purely based on real-time I/O behavior without requiring user-supplied information or offline-profiled application characteristics. ThemisIO supports a variety of fair sharing policies, such as user-fair, size-fair, as well as composite policies, e.g., group-then-user-fair. All these features are enabled by its statistical token design. ThemisIO can alter the execution order of incoming I/O requests based on assigned tokens to precisely balance I/O cycles between applications via time slicing, thereby enforcing processing isolation. Experiments using I/O benchmarks show that ThemisIO sustains 13.5-13.7% higher I/O throughput and 19.5-40.4% lower performance variation than existing algorithms. For real applications, ThemisIO significantly reduces the slowdown by 59.1-99.8% caused by I/O interference.