We can use a hybrid memory system consisting of DRAM and Intel Optane DC Persistent Memory (We call it DCPM in this paper) as DCPM is now commercially available since April 2019. Even if the latency for DCPM is several times higher than that for DRAM, the capacity for DCPM is several times higher than that for DRAM and the cost of DCPM is also several times lower than that for DRAM. In addition, DCPM is non-volatile. A Server with this hybrid memory system could improve the performance for in-memory database systems and virtual machine (VM) systems because these systems often consume a large amount of memory. Moreover, a high-speed shared storage system can be implemented by accessing DCPM via remote direct memory access (RDMA). I assume that some of the DCPM is often assigned as a shared area among other remote servers because applications executed on a server with a hybrid memory system often cannot use the entire capacity of DCPM. This paper evaluates the interference between local memory access and RDMA from a remote server. As a result, I indicate that the interference on this hybrid memory system is significantly different from that on a conventional DRAM-only memory system. I also believe that some kind of throttling implementation is needed when this interference occures.

中文翻译：

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混合存储系统上RDMA与本地访问的干扰分析

我们可以使用由 DRAM 和 Intel Optane DC Persistent Memory（我们在本文中称之为 DCPM）组成的混合内存系统，因为 DCPM 从 2019 年 4 月开始商用。 即使 DCPM 的延迟比 DRAM 高几倍， DCPM的容量比DRAM高几倍，DCPM的成本也比DRAM低几倍。此外，DCPM 是非易失性的。具有这种混合内存系统的服务器可以提高内存数据库系统和虚拟机 (VM) 系统的性能，因为这些系统通常会消耗大量内存。此外，可以通过远程直接内存访问（RDMA）访问 DCPM 来实现高速共享存储系统。我假设某些 DCPM 通常被分配为其他远程服务器之间的共享区域，因为在具有混合内存系统的服务器上执行的应用程序通常无法使用 DCPM 的全部容量。本文评估了本地内存访问和来自远程服务器的 RDMA 之间的干扰。因此，我指出对这种混合内存系统的干扰与传统的仅 DRAM 内存系统上的干扰显着不同。我也相信当这种干扰发生时需要某种节流实现。我指出，对这种混合内存系统的干扰与传统的仅 DRAM 内存系统上的干扰显着不同。我也相信当这种干扰发生时需要某种节流实现。我指出，对这种混合内存系统的干扰与传统的仅 DRAM 内存系统上的干扰显着不同。我也相信当这种干扰发生时需要某种节流实现。