eRPC is a fast and general-purpose RPC library for datacenter networks. Our NSDI 2019 paper describes the system in detail. Documentation is available online.

Some highlights: * Multiple supported networks: Ethernet, InfiniBand, and RoCE * Low latency: 2.3 microseconds round-trip RPC latency with UDP over Ethernet * Performance for small 32-byte RPCs: ~10M RPCs/sec with one CPU core, 60--80M RPCs/sec with one NIC. * Bandwidth for large RPC: 75 Gbps on one connection (one CPU core at server and client) for 8 MB RPCs * Scalability: 20000 RPC sessions per server * End-to-end congestion control that tolerates 100-way incasts * Nested RPCs, and long-running background RPCs * A port of Raft as an example. Our 3-way replication latency is 5.3 microseconds with traditional UDP over Ethernet.

Requirements

• Toolchain: A C++11 compiler and CMake 2.8+
• See

  scripts/packages/

  for required software packages for your distro.
• The latest

  rdma_core

  , preferably installed from source
• For non-Mellanox DPDK-compatible NICs, a system-wide installation from DPDK 19.11.5 LTS sources (i.e.,

  sudo make install T=x86_64-native-linuxapp-gcc
  DESTDIR=/usr

  ). Other DPDK versions are not supported.
• NICs: Fast (10 GbE+) NICs are needed for good performance. eRPC works best with Mellanox Ethernet and InfiniBand NICs. Any DPDK-capable NICs also work well.
• System configuration:
  • At least 1024 huge pages on every NUMA node, and unlimited SHM limits
  • On a machine with

    n

    eRPC processes, eRPC uses kernel UDP ports

    {31850,
    ..., 31850 + n - 1}.

    These ports should be open on the management network. See

    scripts/firewalld/erpc_firewall.sh

    for systems running

    firewalld

    .

eRPC quickstart

• Build and run the test suite:

  cmake . -DPERF=OFF -DTRANSPORT=dpdk; make -j; sudo ctest

  .

  • DPERF=OFF

    enables debugging, which greatly reduces performance. Set

    DPERF=ON

    for performance measurements.
  • Here,

    dpdk

    should be replaced with

    infiniband

    for InfiniBand NICs.
  • A machine with two ports is needed to run the unit tests if DPDK is chosen. Run

    scripts/run-tests-dpdk.sh

    instead of

    ctest

    .
• Run the

  hello_world

  application:

  • cd hello_world

  • Edit the server and client hostnames in

    common.h

  • Based on the transport that eRPC was compiled for, compile

    hello_world

    using

    make dpdk

    , or

    make infiniband

    .
  • Run

    ./server

    at the server, and

    ./client

    at the client
• Generate the documentation:

  doxygen

Supported bare-metal NICs:

• Ethernet/UDP mode:
  • DPDK-enabled NICs: Use

    DTRANSPORT=dpdk

    • We have primarily tested Mellanox CX3--CX5 NICs.
  • DPDK-enabled NICs on Microsoft Azure: Use

    -DTRANSPORT=dpdk -DAZURE=on

• RDMA (InfiniBand/RoCE) NICs: Use

  DTRANSPORT=infiniband

  . Add

  DROCE=on

  if using RoCE.

Running eRPC over DPDK on Microsoft Azure VMs

• eRPC works well on Azure VMs with accelerated networking.

• Configure two Ubuntu 18.04 VMs as below. Use the same resource group and availability zone for both VMs.

  • Uncheck "Accelerated Networking" when launching each VM from the Azure portal (e.g., F32s-v2). For now, this VM should have just the control network (i.e.,

    eth0

    ) and

    lo

    interfaces.
  • Add a NIC to Azure via the Azure CLI:

    az network nic create
    --resource-group  --name 
    --vnet-name  --subnet default
    --accelerated-networking true --subscription  --location 

  • Stop the VM launched earlier, and attach the NIC created in the previous step to the VM (i.e., in "Networking" -> "Attach network interface").
  • Re-start the VM. It should have a new interface called

    eth1

    , which eRPC will use for DPDK traffic.

• Prepare DPDK 19.11.5:

  • rdma-core must be installed from source. First, install its dependencies listed in rdma-core's README. Then, in the

    rdma-core

    directory:

    • cmake .

    • sudo make install

  • Install upstream pre-requisite libraries and modules:

    • sudo apt install make cmake g++ gcc libnuma-dev libgflags-dev numactl

    • sudo modprobe ib_uverbs

    • sudo modprobe mlx4_ib

  • Download the DPDK 19.11.5 tarball and extract it. Other DPDK versions are not supported.
  • Edit

    config/common_base

    by changing

    CONFIG_RTE_LIBRTE_MLX5_PMD

    and

    CONFIG_RTE_LIBRTE_MLX4_PMD

    to

    y

    instead of

    n

    .
  • Build and install DPDK:

    sudo make install T=x86_64-native-linuxapp-gcc
    DESTDIR=/usr

  • Create hugepages:

    sudo bash -c "echo 2048 > /sys/devices/system/node/node0/hugepages/hugepages-2048kB/nr_hugepages"
    sudo mkdir /mnt/huge
    sudo mount -t hugetlbfs nodev /mnt/huge
    

• Build eRPC's library and latency benchmark:

  cmake . -DTRANSPORT=dpdk -DAZURE=on
  make
  make latency
  

• Create the file

  scripts/autorun_process_file

  like below. Here, do not use the IP addresses of the accelerated NIC (i.e., not of

  eth1

  ).

   31850 0
   31850 0
  

• Run the eRPC application (the latency benchmark by default):

  • At VM #1:

    ./scripts/do.sh 0 0

  • At VM #2:

    ./scripts/do.sh 1 0

Configuring and running the provided benchmarks

• The

  apps

  directory contains a suite of benchmarks and examples. The instructions below are for this suite of applications. eRPC can also be simply linked as a library instead (see

  hello_world/

  for an example).
• To build an application, create

  scripts/autorun_app_file

  and change its contents to one of the available directory names in

  apps/

  . See

  scripts/example_autorun_app_file

  for an example. Then generate a Makefile using

  cmake . -DTRANSPORT=dpdk/infiniband

  .
• Each application directory in

  apps/

  contains a config file that must specify all flags defined in

  apps/apps_common.h

  . For example,

  num_processes

  specifies the total number of eRPC processes in the cluster.
• The URIs of eRPC processes in the cluster are specified in

  scripts/autorun_process_file

  . Each line in this file must be
  .
• Run

  scripts/do.sh

  for each process:
  • With single-CPU machines:

    num_processes

    machines are needed. Run

    scripts/do.sh  0

    on machine

    i

    in

    {0, ..., num_processes - 1}

    .
  • With dual-CPU machines:

    num_machines = ceil(num_processes / 2)

    machines are needed. Run

    scripts/do.sh  

    on machine i in

    {0, ..., num_machines - 1}

    .
• To automatically run an application at all processes in

  scripts/autorun_process_file

  , run

  scripts/run-all.sh

  . For some applications, statistics generated in a run can be collected and processed using

  scripts/proc-out.sh

  .

Getting help

• GitHub issues are preferred over email. Please include the following information in the issue:
  • NIC model

  • rdma_core

    version and DPDK version
  • Operating system

Contact

Anuj Kalia

License

    Copyright 2018, Carnegie Mellon University

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.