High capacity persistent memory (PMEM) is finally commercially available in the form of Intel's Optane DC Persistent Memory Module (DCPMM). Researchers have raced to evaluate and understand the performance of DCPMM itself as well as systems and applications designed to leverage PMEM resulting from over a decade of research. Early evaluations of DCPMM show that its behavior is more nuanced and idiosyncratic than previously thought. Several assumptions made about its performance that guided the design of PMEM-enabled systems have been shown to be incorrect. Unfortunately, several peculiar performance characteristics of DCPMM are related to the memory technology (3D-XPoint) used and its internal architecture. It is expected that other technologies (such as STT-RAM, memristor, ReRAM, NVDIMM), with highly variable characteristics, will be commercially shipped as PMEM in the near future. Current evaluation studies fail to understand and categorize the idiosyncratic behavior of PMEM; i.e., how do the peculiarities of DCPMM related to other classes of PMEM. Clearly, there is a need for a study which can guide the design of systems and is agnostic to PMEM technology and internal architecture. In this paper, we first list and categorize the idiosyncratic behavior of PMEM by performing targeted experiments with our proposed PMIdioBench benchmark suite on a real DCPMM platform. Next, we conduct detailed studies to guide the design of storage systems, considering generic PMEM characteristics. The first study guides data placement on NUMA systems with PMEM while the second study guides the design of lock-free data structures, for both eADR- and ADR-enabled PMEM systems. Our results are often counter-intuitive and highlight the challenges of system design with PMEM.
Applications running inside containers or virtual machines, traditionally use TCP/IP for communication in HPC clouds and data centers. The TCP/IP path usually becomes a major performance bottleneck for applications performing NVMe-over-Fabrics (NVMe-oF) based I/O operations in disaggregated storage settings. We propose an adaptive communication channel, called NVMe-over-Adaptive-Fabric (NVMe-oAF), that applications could leverage to eliminate the high-latency and low-bandwidth incurred by remote I/O requests over TCP/IP. NVMe-oAF accelerates I/O intensive applications using locality awareness along with optimized shared memory and TCP/IP paths. The adaptiveness of the fabric stems from the ability to adaptively select shared memory or TCP channel and further applying optimizations for the chosen channel. To evaluate NVMe-oAF, we co-design Intel's SPDK library with our designs and show up to 7.1x bandwidth improvement and up to 4.2x latency reduction for various workloads over commodity TCP/IPbased Ethernet networks (e.g., 10Gbps, 25Gbps, and 100Gbps). We achieve similar (or sometimes better) performance when compared to NVMe-over-RDMA by avoiding the cumbersome management of RDMA in HPC cloud environments. Finally, we also co-design NVMe-oAF with H5bench to showcase the benefit it brings to HDF5 applications. Our evaluation indicates up to a 7x bandwidth improvement when compared with the network file system (NFS).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.