The non-volatile memory (NVM) device is a useful way to solve the memory wall in computers. However, the current I/O software stack in operating systems becomes a performance bottleneck for applications based on NVM devices, especially for key–value stores. We analyzed the characteristics of key–value stores and NVM devices and designed a new embedded key–value store for an NVM device simulator named PMEKV. The embedded processor in NVM devices was used to manage key–value pairs to reduce the data transfer between NVM devices and key–value applications. Meanwhile, it also cut down the data copy between the user space and the kernel space in the operating system to alleviate the I/O software stacks on the efficiency of key–value stores. The architecture, data layout, management strategy, new interface and log strategy of PMEKV are given. Finally, a prototype of PMEKV was implemented based on PMEM. We used YCSB to test and compare it with Redis, MongDB, and Memcache. Meanwhile, the Redis for PMEM named PMEM-Redis and PMEM-KV were also used to test and compared with PMEKV. The results show that PMEKV had the advantage of throughput and adaptability compared with the current key–value stores.

中文翻译：

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用于NVM设备模拟器的新型嵌入式键值存储

非易失性内存（NVM）设备是解决计算机内存不足的有用方法。但是，当前操作系统中的I / O软件堆栈已成为基于NVM设备的应用程序的性能瓶颈，尤其是键值存储。我们分析了键值存储和NVM设备的特性，并为名为PMEKV的NVM设备模拟器设计了一个新的嵌入式键值存储。NVM设备中的嵌入式处理器用于管理键值对，以减少NVM设备和键值应用程序之间的数据传输。同时，它还减少了操作系统中用户空间和内核空间之间的数据复制，从而减轻了I / O软件堆栈在键值存储方面的效率。给出了PMEKV的体系结构，数据布局，管理策略，新接口和日志策略。最后，基于PMEM实现了PMEKV的原型。我们使用YCSB对其进行了测试并将其与Redis，MongDB和Memcache进行比较。同时，还使用PMEM的Redis PMEM-Redis和PMEM-KV进行了测试，并与PMEKV进行了比较。结果表明，与当前的键值存储相比，PMEKV具有吞吐量和适应性的优势。