Research On Optimization Of Semantic-aware Key-value Storage System Based On ZNS SSD

In the age of big data,the advancement of data-intensive applications poses a significant challenge to data center storage costs and efficiency.Due to their large capacity and low cost,Solid-State Drives(SSDs)based on the Zoned Namespace(ZNS)interface are expected to become the core storage component in the next-generation data center.To effectively utilize the benefits of ZNS SSD,it combines an abstract zoned interface with NAND flash access features,allowing the host to control the data layout in the SSD directly.Using the current popular key-value storage application Rocks DB database as an example,it is essential to construct a high-performance key-value storage system that integrates software and hardware.To address the issue of low data access efficiency on ZNS SSD devices,we propose a data semantic-aware ZNS SSD data placement strategy.Through the I/O stack,the semantic information of the high-performance storage unit in the SSD is transferred to the storage backend of the key-value storage engine.Using the inherent write restrictions and data features in the key-value storage engine Rocks DB,the write-ahead log files and a portion of the hot data are stored in high-performance storage units and mapped to the SLC flash memory to improve throughput.The experimental results show that,compared to the prior key-value storage system,the read bandwidth can be increased by up to 51.6% and the write bandwidth can be increased by up to 41.1%.To address the low efficiency of multi-column family management,we propose a multicolumn family semantic-aware ZNS SSD zoned storage strategy.The column family information for key-value pairs in Rocks DB is delivered to the file system storage backend.Zen FS can create a zoned storage data placement strategy that meets the requirements of multi-column families,and improves space utilization.The experimental results show that,compared to the key-value storage system before the improvement,the write bandwidth can be increased by up to 33.7%,and the reclaimable zone capacity can be reduced by 77.7%on average.Combining the two strategies increases write bandwidth by up to 96.0% on average while decreasing the reclaimable zone capacity by 89.6%.