I/O Acceleration via Multi-Tiered Data Buffering and Prefetching  

作　　者：Anthony Kougkas Hariharan Devarajan Xian-He Sun 

机构地区：[1]Department of Computer Science,Illinois Institute of Technology,Chicago 60616,U.S.A

出　　处：《Journal of Computer Science & Technology》2020年第1期92-120,共29页计算机科学技术学报（英文版）

基　　金：This work is funded by the National Science Foundation of USA under Grants Nos.OCI-1835764 and CSR-1814872。

摘　　要：Modern High-Performance Computing(HPC)systems are adding extra layers to the memory and storage hierarchy,named deep memory and storage hierarchy(DMSH),to increase I/O performance.New hardware technologies,such as NVMe and SSD,have been introduced in burst buffer installations to reduce the pressure for external storage and boost the burstiness of modern I/O systems.The DMSH has demonstrated its strength and potential in practice.However,each layer of DMSH is an independent heterogeneous system and data movement among more layers is significantly more complex even without considering heterogeneity.How to efficiently utilize the DMSH is a subject of research facing the HPC community.Further,accessing data with a high-throughput and low-latency is more imperative than ever.Data prefetching is a well-known technique for hiding read latency by requesting data before it is needed to move it from a high-latency medium(e.g.,disk)to a low-latency one(e.g.,main memory).However,existing solutions do not consider the new deep memory and storage hierarchy and also suffer from under-utilization of prefetching resources and unnecessary evictions.Additionally,existing approaches implement a client-pull model where understanding the application's I/O behavior drives prefetching decisions.Moving towards exascale,where machines run multiple applications concurrently by accessing files in a workflow,a more data-centric approach resolves challenges such as cache pollution and redundancy.In this paper,we present the design and implementation of Hermes:a new,heterogeneous-aware,multi-tiered,dynamic,and distributed I/O buffering system.Hermes enables,manages,supervises,and,in some sense,extends I/O buffering to fully integrate into the DMSH.We introduce three novel data placement policies to efficiently utilize all layers and we present three novel techniques to perform memory,metadata,and communication management in hierarchical buffering systems.Additionally,we demonstrate the benefits of a truly hierarchical data prefetcher that ado

关 键 词：I/O BUFFERING heterogeneous BUFFERING layered BUFFERING deep memory hierarchy BURST BUFFERS hierarchical data PREFETCHING DATA-CENTRIC architecture 

分 类 号：TP39[自动化与计算机技术—计算机应用技术]