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Observation and Optimization on Garbage Collection of Flash Memories: The View in Performance Cliff

The recent development of 3D flash memories has promoted the widespread application of SSDs in modern storage systems by providing large storage capacity and low cost. Garbage collection (GC) as a time-consuming but necessary operation in flash memories largely affects the performance. In this paper...

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Autores principales: Du, Yajuan, Liu, Wei, Gao, Yuan, Ausavarungnirun, Rachata
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8307601/
https://www.ncbi.nlm.nih.gov/pubmed/34357256
http://dx.doi.org/10.3390/mi12070846
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author Du, Yajuan
Liu, Wei
Gao, Yuan
Ausavarungnirun, Rachata
author_facet Du, Yajuan
Liu, Wei
Gao, Yuan
Ausavarungnirun, Rachata
author_sort Du, Yajuan
collection PubMed
description The recent development of 3D flash memories has promoted the widespread application of SSDs in modern storage systems by providing large storage capacity and low cost. Garbage collection (GC) as a time-consuming but necessary operation in flash memories largely affects the performance. In this paper, we perform a comprehensive experimental study on how garbage collection impacts the performance of flash-based SSDs, in the view of performance cliff that closely relates to Quality of Service (QoS). According to the study results using real-world workloads, we first observe that GC occasionally causes response time spikes, which we call the performance cliff problem. Then, we find that 3D SSDs exacerbate the situation by inducing a much higher number of page migrations during GC. To relieve the performance cliff problem, we propose PreGC to assist normal GC. The key idea is to distribute the page migrations into the period before normal GC, thus leading to a reduction in page migrations during the GC period. Comprehensive experiments with real-world workloads have been performed on the SSDsim simulator. Experimental results show that PreGC can efficiently relieve the performance cliff by reducing the tail latency from the 90th to 99.99th percentiles while inducing a little extra write amplification.
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spelling pubmed-83076012021-07-25 Observation and Optimization on Garbage Collection of Flash Memories: The View in Performance Cliff Du, Yajuan Liu, Wei Gao, Yuan Ausavarungnirun, Rachata Micromachines (Basel) Article The recent development of 3D flash memories has promoted the widespread application of SSDs in modern storage systems by providing large storage capacity and low cost. Garbage collection (GC) as a time-consuming but necessary operation in flash memories largely affects the performance. In this paper, we perform a comprehensive experimental study on how garbage collection impacts the performance of flash-based SSDs, in the view of performance cliff that closely relates to Quality of Service (QoS). According to the study results using real-world workloads, we first observe that GC occasionally causes response time spikes, which we call the performance cliff problem. Then, we find that 3D SSDs exacerbate the situation by inducing a much higher number of page migrations during GC. To relieve the performance cliff problem, we propose PreGC to assist normal GC. The key idea is to distribute the page migrations into the period before normal GC, thus leading to a reduction in page migrations during the GC period. Comprehensive experiments with real-world workloads have been performed on the SSDsim simulator. Experimental results show that PreGC can efficiently relieve the performance cliff by reducing the tail latency from the 90th to 99.99th percentiles while inducing a little extra write amplification. MDPI 2021-07-20 /pmc/articles/PMC8307601/ /pubmed/34357256 http://dx.doi.org/10.3390/mi12070846 Text en © 2021 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Du, Yajuan
Liu, Wei
Gao, Yuan
Ausavarungnirun, Rachata
Observation and Optimization on Garbage Collection of Flash Memories: The View in Performance Cliff
title Observation and Optimization on Garbage Collection of Flash Memories: The View in Performance Cliff
title_full Observation and Optimization on Garbage Collection of Flash Memories: The View in Performance Cliff
title_fullStr Observation and Optimization on Garbage Collection of Flash Memories: The View in Performance Cliff
title_full_unstemmed Observation and Optimization on Garbage Collection of Flash Memories: The View in Performance Cliff
title_short Observation and Optimization on Garbage Collection of Flash Memories: The View in Performance Cliff
title_sort observation and optimization on garbage collection of flash memories: the view in performance cliff
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8307601/
https://www.ncbi.nlm.nih.gov/pubmed/34357256
http://dx.doi.org/10.3390/mi12070846
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