论文标题
启发闪存存储以通过对象写入流
Enlightening Flash Storage to Stream Writes by Objects
论文作者
论文摘要
对于写入请求，今天的闪存存储无法区分其来自的逻辑对象。在这种符合对象的闪光设备中，从不同对象的同时写入将以到达顺序包装到闪存块。因此，具有不同寿命的对象被多路复用到相同的闪存块上。这种多路复用引起的写入扩增，使性能恶化。解决多路复用问题，我们提出了一个新颖的界面，用于闪存存储，FlashAlloc。它用于将逻辑对象的逻辑地址范围传递给闪存存储，从而启发以通过对象写入的存储。对象感知的闪存存储可以从不同的对象中删除具有不同死亡时间的不同对象，以每个对象专用的闪存块。鉴于流行的数据存储使用对象（例如，RocksDB中的Sstables）单独写入，我们可以实现，与现有解决方案不同，仅通过在对象创建上调用FlashAlloc来透明写入流。我们使用开源SSD原型的实验结果表明，FlashAlloc可以分别减少RockSDB，F2FS和MySQL中的写入扩增因子（WAF），分别为1.5、2.5和0.3，从而分别通过2X，1.8x和1.2x改善吞吐量。特别是，FlashAlloc会减轻多材料的干扰。当RockSDB和MySQL一起在同一SSD上运行时，Flashalloc将WAF从4.2降低到2.5，并增加了吞吐量。
For a write request, today flash storage cannot distinguish the logical object it comes from. In such object-oblivious flash devices, concurrent writes from different objects are simply packed in their arrival order to flash memory blocks; hence objects with different lifetimes are multiplexed onto the same flash blocks. This multiplexing incurs write amplification, worsening the performance. Tackling the multiplexing problem, we propose a novel interface for flash storage, FlashAlloc. It is used to pass the logical address ranges of logical objects to the flash storage and thus enlighten the storage to stream writes by objects. The object-aware flash storage can de-multiplex writes from different objects with distinct deathtimes into per-object dedicated flash blocks. Given that popular data stores separate writes using objects (e.g., SSTables in RocksDB), we can achieve, unlike the existing solutions, transparent write streaming just by calling FlashAlloc upon object creation. Our experimental results using an open-source SSD prototype demonstrate that FlashAlloc can reduce write amplification factor (WAF) in RocksDB, F2FS, and MySQL by 1.5, 2.5, and 0.3, respectively and thus improve throughput by 2x, 1.8x, and 1.2x, respectively. In particular, FlashAlloc will mitigate the interference among multitenants. When RocksDB and MySQL were run together on the same SSD, FlashAlloc decreased WAF from 4.2 to 2.5 and doubled their throughputs.
