This article presents XMemPod, a hierarchical disaggregated memory orchestration system. XMemPod virtualizes cluster wide memory to scale large memory workloads in virtualized clouds. It makes three novel contributions: (1) XMemPod offers efficient, transparent, and dynamic sharing of available memory that is disaggregated across VMs on the same host or in the cluster. (2) XMemPod provides a hierarchical memory expansion framework, which enables memory-intensive workloads on a VM to expand its memory demand over virtualized host memory first, and remote memory next, before resorting to external disk. (3) XMemPod provides a suite of optimization techniques to further improve the utilization and access latency of disaggregated memory. XMemPod is deployed on a virtualized RDMA cluster without any modifications to user applications and the OSes. Evaluated with multiple workloads on unmodified Spark, Apache Hadoop, Memcached, Redis and VoltDB, using XMemPod, throughputs of these applications improve by 11x to 612x over conventional Linux, and by 1.7x to 14x over the existing representative remote memory paging systems, and yet the total amount of network traffic consumed by XMemPod is only 24 percent of the existing approaches.

中文翻译：

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分解内存的分层编排

本文介绍 XMemPod，一个分层分解的内存编排系统。XMemPod 将集群范围的内存虚拟化，以在虚拟化云中扩展大型内存工作负载。它做出了三个新的贡献：(1) XMemPod 提供了有效、透明和动态的可用内存共享，这些内存在同一主机或集群中的 VM 之间分解。(2) XMemPod 提供了一个分层的内存扩展框架，它可以让 VM 上的内存密集型工作负载首先扩展其内存需求，而不是虚拟化主机内存，然后是远程内存，然后再求助于外部磁盘。(3) XMemPod 提供了一套优化技术，以进一步提高分解内存的利用率和访问延迟。XMemPod 部署在虚拟化 RDMA 集群上，无需对用户应用程序和操作系统进行任何修改。