Key Value SSD的技术原理和应用

1、Key/Value SSD的技术原理和应用Unstructed data dominatesTraditional KV StoreTraditional KV StoreApplicationRocksDB Ext4BlockDevice SSDTraditional KV StoreApplicationRocksDB Ext4BlockDeviceSSD1, Compaction操作导致几倍的写放大.2, Write LogTraditional KV StoreApplicationRocksDBExt4BlockDeviceSSD1, block bitmap 2, file map

2、 table. 3, logTraditional KV StoreApplicationRocksDB Ext4BlockDeviceSSD1, Linux Block Device接口是为机械硬 盘设计的，并不能发挥出SSD的优势和 特性。Log on LogApplicationRocksDB Ext4BlockDevice SSDLog+DataLog+DataLogStructuredTraditional SSD vs KV SSDfSSDKVSSDNew Software ArchitectureApplicationRocksDB Ext4BlockDevice SSDAppl

3、icationKVSSDKV SSD Software StackOpenChannelSSDKVSSDDriverKVLibrary/ToolsApplicationsHardwareKernelSpaceUserSpaceOpen Channel SSDNVMEDriverLightNVM layerBlock Device DriverKVSSDDriverLibLightNVMKV LibaryAPPAPPAPPAPPKVSSD Driverkey2addr index tableLog structuredGCWLCompressionKVSSD Driver Read/Write

4、FlowIndex TablePysical LocationNand FlashNand Flash PageMetadataKeyValueNand FlashNand Flash PageDRAMIndex TablePysical LocationKV Library APIopen_db/close_dbkv_put/kv_get/kv_deleteiteratorwrite_batch/read_batchsnapshotColumn FamilyRead CacheKVSSD OverviewKEY_SIZE: 1B 127BVALUE_SIZE: 1B 40MB(1KB+ better)PersistencyAtomic WriteKVSSD和RocksDB的随机写性能对比45240050100150200250KV_PUTperSecondK/sKV_PUT性能对比20 threads RocksDBKV SSD41046050150100250200300350400450写入数据量 MB/sSSD写入数据量对比 IOPS：45K/SRocksDBKV SSD测试条件： key