numam-spdk/scripts/perf/nvmf

Running NVMe-OF Performance Test Cases

Scripts contained in this directory are used to run TCP and RDMA benchmark tests, that are later published at spdk.io performance reports section. To run the scripts in your environment please follow steps below.

Test Systems Requirements

• The OS installed on test systems must be a Linux OS. Scripts were primarily used on systems with Fedora and Ubuntu 18.04/20.04 distributions.
• Each test system must have at least one RDMA-capable NIC installed for RDMA tests. For TCP tests any TCP-capable NIC will do. However, high-bandwidth, high-performance NICs like Intel E810 CQDA2 or Mellanox ConnectX-5 are suggested because the NVMe-oF workload is network bound. So, if you use a NIC capable of less than 100Gbps on NVMe-oF target system, you will quickly saturate your NICs.
• Python3 interpreter must be available on all test systems. Paramiko and Pandas modules must be installed.
• nvmecli package must be installed on all test systems.
• fio must be downloaded from Github and built. This must be done on Initiator test systems to later build SPDK with "--with-fio" option.
• All test systems must have a user account with a common name, password and passwordless sudo enabled.
• mlnx-tools package must be downloaded to /usr/src/local directory in order to configure NIC ports IRQ affinity. If custom directory is to be used, then it must be set using irq_scripts_dir option in Target and Initiator configuration sections.

Optional

• For test using the Kernel Target, nvmet-cli must be downloaded and build on Target system. nvmet-cli is available here.

Manual configuration

Before running the scripts some manual test systems configuration is required:

• Configure IP address assignment on the NIC ports that will be used for test. Make sure to make these assignments persistent, as in some cases NIC drivers may be reloaded.
• Adjust firewall service to allow traffic on IP - port pairs used in test (or disable firewall service completely if possible).
• Adjust or completely disable local security engines like AppArmor or SELinux.

JSON configuration for test run automation

An example json configuration file with the minimum configuration required to automate NVMe-oF testing is provided in this repository. The following sub-chapters describe each configuration section in more detail.

General settings section

"general": {
    "username": "user",
    "password": "password",
    "transport": "transport_type",
    "skip_spdk_install": bool
}

Required:

• username - username for the SSH session
• password - password for the SSH session
• transport - transport layer to be used throughout the test ("tcp" or "rdma")

Optional:

• skip_spdk_install - by default SPDK sources will be copied from Target to the Initiator systems each time run_nvmf.py script is run. If the SPDK is already in place on Initiator systems and there's no need to re-build it, then set this option to true. Default: false.

Target System Configuration

"target": {
  "mode": "spdk",
  "nic_ips": ["192.0.1.1", "192.0.2.1"],
  "core_mask": "[1-10]",
  "null_block_devices": 8,
  "nvmet_bin": "/path/to/nvmetcli",
  "sar_settings": [true, 30, 1, 60],
  "pcm_settings": [/tmp/pcm, 30, 1, 60],
  "enable_bandwidth": [true, 60],
  "enable_dpdk_memory": [true, 30]
  "num_shared_buffers": 4096,
  "scheduler_settings": "static",
  "zcopy_settings": false,
  "dif_insert_strip": true,
  "null_block_dif_type": 3
}

Required:

• mode - Target application mode, "spdk" or "kernel".
• nic_ips - IP addresses of NIC ports to be used by the target to export NVMe-oF subsystems.
• core_mask - Used by SPDK target only. CPU core mask either in form of actual mask (i.e. 0xAAAA) or core list (i.e. [0,1,2-5,6). At this moment the scripts cannot restrict the Kernel target to only use certain CPU cores. Important: upper bound of the range is inclusive!

Optional, common:

• null_block_devices - int, number of null block devices to create. Detected NVMe devices are not used if option is present. Default: 0.
• sar_settings - [bool, int(x), int(y), int(z)]; Enable SAR CPU utilization measurement on Target side. Wait for "x" seconds before starting measurements, then do "z" samples with "y" seconds intervals between them. Default: disabled.
• pcm_settings - [path, int(x), int(y), int(z)]; Enable PCM measurements on Tartet side. Measurements include CPU, memory and power consumption. "path" points to a directory where pcm executables are present. Default: disabled.
• enable_bandwidth - [bool, int]. Wait a given number of seconds and run bwm-ng until the end of test to measure bandwidth utilization on network interfaces. Default: disabled.
• tuned_profile - tunedadm profile to apply on the system before starting the test.
• irq_scripts_dir - path to scripts directory of Mellanox mlnx-tools package; Used to run set_irq_affinity.sh script. Default: /usr/src/local/mlnx-tools/ofed_scripts

Optional, Kernel Target only:

• nvmet_bin - path to nvmetcli binary, if not available in $PATH. Only for Kernel Target. Default: "nvmetcli".

Optional, SPDK Target only:

• zcopy_settings - bool. Disable or enable target-size zero-copy option. Default: false.
• scheduler_settings - str. Select SPDK Target thread scheduler (static/dynamic). Default: static.
• num_shared_buffers - int, number of shared buffers to allocate when creating transport layer. Default: 4096.
• dif_insert_strip - bool. Only for TCP transport. Enable DIF option when creating transport layer. Default: false.
• null_block_dif_type - int, 0-3. Level of DIF type to use when creating null block bdev. Default: 0.
• enable_dpdk_memory - [bool, int]. Wait for a given number of seconds and call env_dpdk_get_mem_stats RPC call to dump DPDK memory stats. Typically wait time should be at least ramp_time of fio described in another section.
• adq_enable - bool; only for TCP transport. Configure system modules, NIC settings and create priority traffic classes for ADQ testing. You need and ADQ-capable NIC like the Intel E810.
• bpf_scripts - list of bpftrace scripts that will be attached during the test run. Available scripts can be found in the spdk/scripts/bpf directory.

Initiator system settings section

There can be one or more initiatorX setting sections, depending on the test setup.

"initiator1": {
  "ip": "10.0.0.1",
  "nic_ips": ["192.0.1.2"],
  "target_nic_ips": ["192.0.1.1"],
  "mode": "spdk",
  "fio_bin": "/path/to/fio/bin",
  "nvmecli_bin": "/path/to/nvmecli/bin",
  "cpus_allowed": "0,1,10-15",
  "cpus_allowed_policy": "shared",
  "num_cores": 4,
  "cpu_frequency": 2100000,
  "adq_enable": false,
  "kernel_engine": "io_uring"
}

Required:

• ip - management IP address of initiator system to set up SSH connection.
• nic_ips - list of IP addresses of NIC ports to be used in test, local to given initiator system.
• target_nic_ips - list of IP addresses of Target NIC ports to which initiator will attempt to connect to.
• mode - initiator mode, "spdk" or "kernel". For SPDK, the bdev fio plugin will be used to connect to NVMe-oF subsystems and submit I/O. For "kernel", nvmecli will be used to connect to NVMe-oF subsystems and fio will use the libaio ioengine to submit I/Os.

Optional, common:

• nvmecli_bin - path to nvmecli binary; Will be used for "discovery" command (for both SPDK and Kernel modes) and for "connect" (in case of Kernel mode). Default: system-wide "nvme".
• fio_bin - path to custom fio binary, which will be used to run IO. Additionally, the directory where the binary is located should also contain fio sources needed to build SPDK fio_plugin for spdk initiator mode. Default: /usr/src/fio/fio.
• cpus_allowed - str, list of CPU cores to run fio threads on. Takes precedence before num_cores setting. Default: None (CPU cores randomly allocated). For more information see man fio.
• cpus_allowed_policy - str, "shared" or "split". CPU sharing policy for fio threads. Default: shared. For more information see man fio.
• num_cores - By default fio threads on initiator side will use as many CPUs as there are connected subsystems. This option limits the number of CPU cores used for fio threads to this number; cores are allocated randomly and fio filename parameters are grouped if needed. cpus_allowed option takes precedence and num_cores is ignored if both are present in config.
• cpu_frequency - int, custom CPU frequency to set. By default test setups are configured to run in performance mode at max frequencies. This option allows user to select CPU frequency instead of running at max frequency. Before using this option intel_pstate=disable must be set in boot options and cpupower governor be set to userspace.
• tuned_profile - tunedadm profile to apply on the system before starting the test.
• irq_scripts_dir - path to scripts directory of Mellanox mlnx-tools package; Used to run set_irq_affinity.sh script. Default: /usr/src/local/mlnx-tools/ofed_scripts
• kernel_engine - Select fio ioengine mode to run tests. io_uring libraries and io_uring capable fio binaries must be present on Initiator systems! Available options:
  • libaio (default)
  • io_uring

Optional, SPDK Initiator only:

• adq_enable - bool; only for TCP transport. Configure system modules, NIC settings and create priority traffic classes for ADQ testing. You need an ADQ-capable NIC like Intel E810.

Fio settings section

"fio": {
  "bs": ["4k", "128k"],
  "qd": [32, 128],
  "rw": ["randwrite", "write"],
  "rwmixread": 100,
  "rate_iops": 10000,
  "num_jobs": 2,
  "run_time": 30,
  "ramp_time": 30,
  "run_num": 3
}

Required:

• bs - fio IO block size
• qd - fio iodepth
• rw - fio rw mode
• rwmixread - read operations percentage in case of mixed workloads
• num_jobs - fio numjobs parameter Note: may affect total number of CPU cores used by initiator systems
• run_time - fio run time
• ramp_time - fio ramp time, does not do measurements
• run_num - number of times each workload combination is run. If more than 1 then final result is the average of all runs.

Optional:

• rate_iops - limit IOPS to this number

Test Combinations

It is possible to specify more than one value for bs, qd and rw parameters. In such case script creates a list of their combinations and runs IO tests for all of these combinations. For example, the following configuration:

  "bs": ["4k"],
  "qd": [32, 128],
  "rw": ["write", "read"]

results in following workloads being tested:

• 4k-write-32
• 4k-write-128
• 4k-read-32
• 4k-read-128

Important note about queue depth parameter

qd in fio settings section refers to iodepth generated per single fio target device ("filename" in resulting fio configuration file). It is re-calculated while the script is running, so generated fio configuration file might contain a different value than what user has specified at input, especially when also using "numjobs" or initiator "num_cores" parameters. For example:

Target system exposes 4 NVMe-oF subsystems. One initiator system connects to all of these systems.

Initiator configuration (relevant settings only):

"initiator1": {
  "num_cores": 1
}

Fio configuration:

"fio": {
  "bs": ["4k"],
  "qd": [128],
  "rw": ["randread"],
  "rwmixread": 100,
  "num_jobs": 1,
  "run_time": 30,
  "ramp_time": 30,
  "run_num": 1
}

In this case generated fio configuration will look like this (relevant settings only):

[global]
numjobs=1

[job_section0]
filename=Nvme0n1
filename=Nvme1n1
filename=Nvme2n1
filename=Nvme3n1
iodepth=512

num_cores option results in 4 connected subsystems to be grouped under a single fio thread (job_section0). Because iodepth is local to job_section0, it is distributed between each filename local to job section in round-robin (by default) fashion. In case of fio targets with the same characteristics (IOPS & Bandwidth capabilities) it means that iodepth is distributed roughly equally. Ultimately above fio configuration results in iodepth=128 per filename.

numjobs higher than 1 is also taken into account, so that desired qd per filename is retained:

[global]
numjobs=2

[job_section0]
filename=Nvme0n1
filename=Nvme1n1
filename=Nvme2n1
filename=Nvme3n1
iodepth=256

Besides run_num, more information on these options can be found in man fio.

Running the test

Before running the test script run the spdk/scripts/setup.sh script on Target system. This binds the devices to VFIO/UIO userspace driver and allocates hugepages for SPDK process.

Run the script on the NVMe-oF target system:

cd spdk
sudo PYTHONPATH=$PYTHONPATH:$PWD/scripts scripts/perf/nvmf/run_nvmf.py

By default script uses config.json configuration file in the scripts/perf/nvmf directory. You can specify a different configuration file at runtime as below:

sudo PYTHONPATH=$PYTHONPATH:$PWD/scripts scripts/perf/nvmf/run_nvmf.py -c /path/to/config.json

PYTHONPATH environment variable is needed because script uses SPDK-local Python modules. If you'd like to get rid of PYTHONPATH=$PYTHONPATH:$PWD/scripts you need to modify your environment so that Python interpreter is aware of spdk/scripts directory.

Test Results

Test results for all workload combinations are printed to screen once the tests are finished. Additionally all aggregate results are saved to /tmp/results/nvmf_results.conf Results directory path can be changed by -r script parameter.