performance_test
Tool to test performance of ROS2 and DDS data layers and communication.
README
performance_test
[TOC]
The performance_test tool tests latency and other performance metrics of various middleware implementations that support a pub/sub pattern. It is used to simulate non-functional performance of your application.
The performance_test tool allows you to quickly set up a pub/sub configuration, e.g. number of publisher/subscribers, message size, QOS settings, middleware. The following metrics are automatically recorded when the application is running:
latency: corresponds to the time a message takes to travel from a publisher to subscriber. The latency is measured by timestamping the sample when it’s published and subtracting the timestamp (from the sample) from the measured time when the sample arrives at the subscriber (only logged when a subscriber is created)
CPU usage: percentage of the total system wide CPU usage (logged separately for each instance of
perf_test
)resident memory: heap allocations, shared memory segments, stack (used for system’s internal work) (logged separately for each instance of
perf_test
)sample statistics: number of samples received, sent, and lost per experiment run.
This master
branch is compatible with the following ROS 2 versions
rolling
jazzy
iron
humble
galactic
foxy
eloquent
dashing
Apex.OS
How to use this document
Start here for a quick example of building and running the performance_test tool with the Cyclone DDS plugin.
If needed, find more detailed information about building and running
Or, if the quick example is good enough, skip ahead to the list of supported middleware plugins to learn how to test a specific middleware implementation.
Check out the tools for visualizing the results
If desired, read about the design and architecture of the tool.
Example
This example shows how to test the non-functional performance of the following configuration:
Option |
Value |
---|---|
Plugin |
Cyclone DDS |
Message type |
Array1k |
Publishing rate |
100Hz |
Topic name |
test_topic |
Duration of the experiment |
30s |
Number of publisher(s) |
1 (default) |
Number of subscriber(s) |
1 (default) |
Install ROS 2
Install Cyclone DDS to /opt/cyclonedds
Build performance_test with the CMake build flag for Cyclone DDS:
source /opt/ros/rolling/setup.bash cd ~/perf_test_ws colcon build --cmake-args -DPERFORMANCE_TEST_PLUGIN=CYCLONEDDS source ./install/setup.bash
Run with the communication plugin option for Cyclone DDS:
mkdir experiment
./install/performance_test/lib/performance_test/perf_test --communication CycloneDDS
--msg Array1k
--rate 100
--topic test_topic
--max-runtime 30
--logfile experiment/log.csv
At the end of the experiment, a CSV log file will be generated in the experiment folder with a name
that starts with log
.
Building the performance_test tool
For a simple example, see Dockerfile.rclcpp.
The performance_test tool is structured as a ROS 2 package, so colcon
is used to build it.
Therefore, you must source a ROS 2 installation:
source /opt/ros/rolling/setup.bash
Select a middleware plugin from this list. Then build the performance_test tool with the selected middleware:
mkdir -p ~/perf_test_ws/src
cd ~/perf_test_ws/src
git clone https://gitlab.com/ApexAI/performance_test.git
cd ..
# At this stage, you need to choose which middleware you want to use
# The list of available flags is described in the middleware plugins section
# Square brackets denote optional arguments, like in the Python documentation.
colcon build --cmake-args -DCMAKE_BUILD_TYPE=Release -DPERFORMANCE_TEST_PLUGIN=<plugin>
source install/setup.bash
Running an experiment
The performance_test experiments are run through the perf_test
executable.
To find the available settings, run with --help
(note the required and default arguments):
~/perf_test_ws$ ./install/performance_test/lib/performance_test/perf_test --help
The
-c
argument should match the selected middleware plugin from the build phase.The
--msg
argument should be one of the supported message types, which are shown in the--help
output.
Single machine or distributed system?
Based on the configuration you want to test, the usage of the performance_test tool differs. The different possibilities are explained below.
For running tests on a single machine, you can choose between the following options:
Intraprocess means that the publisher and subscriber threads are in the same process.
perf_test <options> --num-sub-threads 1 --num-pub-threads 1
Interprocess means that the publisher and subscriber are in different processes. To test interprocess communication, two instances of the performance_test must be run, e.g.
# Start the subscriber first perf_test <options> --num-sub-threads 1 --num-pub-threads 0 & sleep 1 # give the subscriber time to finish initializing perf_test <options> --num-sub-threads 0 --num-pub-threads 1
On a distributed system, testing latency is difficult, because the clocks are probably not perfectly synchronized between the two devices. To work around this, the performance_test tool supports relay mode, which allows for a round-trip style of communication:
# On the main machine
perf_test <options> --roundtrip-mode Main
# On the relay machine:
perf_test <options> --roundtrip-mode Relay
In relay mode, the Main machine sends messages to the Relay machine, which immediately sends the messages back. The Main machine receives the relayed message, and reports the round-trip latency. Therefore, the reported latency will be roughly double the latency compared to the latency reported in non-relay mode.
Single machine, single thread
An intra-thread configuration is experimentally supported, in which a publisher and subscriber both operate in the same thread. The publisher writes a messages, and the subscriber immediately takes it.
perf_test <options> -e INTRA_THREAD
Notes:
This is only available when zero copy transfer is enabled
This requires exactly one publisher and one subscriber
This is not compatible with roundtrip mode
Middleware plugins
The performance test tool can measure the performance of a variety of communication solutions from different vendors. In this case there is no rclcpp or rmw layer overhead over the publisher and subscriber routines.
The performance_test tool implements an executor that runs the publisher(s) and/or the subscriber(s) in their own thread.
The following plugins are currently implemented:
Eclipse Cyclone DDS
CMake build flag:
-DPERFORMANCE_TEST_PLUGIN=CYCLONEDDS
Communication plugin:
-c CycloneDDS
Docker file: Dockerfile.CycloneDDS
Available transports:
Cyclone DDS zero copy requires RouDi to be running.
Pub/sub in same process
Pub/sub in different processes on same machine
Pub/sub in different machines
INTRA (default), SHMEM (
--shared-memory
), LoanedSamples (--zero-copy
)UDP (default), SHMEM (
--shared-memory
), LoanedSamples (--zero-copy
)UDP
Eclipse Cyclone DDS C++ binding
CMake build flag:
-DPERFORMANCE_TEST_PLUGIN=CYCLONEDDS_CXX
Communication plugin:
-c CycloneDDS-CXX
Docker file: Dockerfile.CycloneDDS-CXX
Available transports:
Cyclone DDS zero copy requires the RouDi to be running.
Pub/sub in same process
Pub/sub in different processes on same machine
Pub/sub in different machines
INTRA (default), SHMEM (
--shared-memory
), LoanedSamples (--zero-copy
)UDP (default), SHMEM (
--shared-memory
), LoanedSamples (--zero-copy
)UDP
Eclipse iceoryx
CMake build flag:
-DPERFORMANCE_TEST_PLUGIN=ICEORYX
Communication plugin:
-c iceoryx
Docker file: Dockerfile.iceoryx
The iceoryx plugin is not a DDS implementation.
The DDS-specific options (such as domain ID, durability, and reliability) do not apply.
To run with the iceoryx plugin, RouDi must be running.
Available transports:
Pub/sub in same process
Pub/sub in different processes on same machine
Pub/sub in different machines
LoanedSamples
LoanedSamples
Not supported by performance_test
eProsima Fast DDS
CMake build flag:
-DPERFORMANCE_TEST_PLUGIN=FASTDDS
Communication plugin:
-c FastRTPS
Docker file: Dockerfile.FastDDS
Available transports:
Pub/sub in same process
Pub/sub in different processes on same machine
Pub/sub in different machines
INTRA (default), LoanedSamples (
--zero-copy
)SHMEM (default), LoanedSamples (
--zero-copy
)UDP
OCI OpenDDS
CMake build flag:
-DPERFORMANCE_TEST_PLUGIN=OPENDDS
Communication plugin:
-c OpenDDS
Docker file: Dockerfile.OpenDDS
Available transports:
Pub/sub in same process
Pub/sub in different processes on same machine
Pub/sub in different machines
TCP
TCP
TCP
RTI Connext DDS
CMake build flag:
-DPERFORMANCE_TEST_PLUGIN=CONNEXTDDS
Communication plugin:
-c ConnextDDS
Docker file: Not available
A license is required
You need to source an RTI Connext DDS environment.
If RTI Connext DDS was installed with ROS 2 (Linux only):
source /opt/rti.com/rti_connext_dds-5.3.1/setenv_ros2rti.bash
If RTI Connext DDS is installed separately, you can source the following script to set the environment:
source <connextdds_install_path>/resource/scripts/rtisetenv_<arch>.bash
Available transports:
Pub/sub in same process
Pub/sub in different processes on same machine
Pub/sub in different machines
INTRA
SHMEM
UDP
RTI Connext DDS Micro
CMake build flag:
-DPERFORMANCE_TEST_PLUGIN=CONNEXTDDSMICRO
Communication plugin:
-c ConnextDDSMicro
Docker file: Not available
A license is required
Available transports:
Pub/sub in same process
Pub/sub in different processes on same machine
Pub/sub in different machines
INTRA
SHMEM
UDP
Framework plugins
The performance_test tool can also measure the end-to-end latency of a framework. In this case, the executor of the framework is used to run the publisher(s) and/or the subscriber(s). The potential overhead of the rclcpp or rmw layer is measured.
ROS 2
The performance test tool can also measure the performance of a variety of RMW implementations,
through the ROS 2 rclcpp::publisher
and rclcpp::subscriber
API.
CMake build flag:
-DPERFORMANCE_TEST_PLUGIN=ROS2
(default)Communication plugin:
Callback with Single Threaded Executor:
-c rclcpp-single-threaded-executor
Callback with Static Single Threaded Executor:
-c rclcpp-static-single-threaded-executor
rclcpp::WaitSet
:-c rclcpp-waitset
Docker file: Dockerfile.rclcpp
Available underlying RMW implementations:
ROS 2 Rolling is pre-configured to use
rmw_fastrtps_cpp
Follow these instructions to use a different RMW implementation
Available transports: depends on underlying RMW implementation
LoanedSamples are available (
--zero-copy
) forROS_DISTRO = foxy
and above
Apex.OS
Apex.OS
CMake build flag:
-DPERFORMANCE_TEST_PLUGIN=APEX_OS
It is also required to
source /opt/ApexOS/setup.bash
instead of a ROS 2 distribution
Communication plugin:
-c ApexOSPollingSubscription
Docker file: Not available
Available underlying RMW implementations:
rmw_apex_middleware
Available transports:
Pub/sub in same process
Pub/sub in different processes on same machine
Pub/sub in different machines
UDP (default), SHMEM (
--shared-memory
), LoanedSamples (--zero_copy
)UDP (default), SHMEM (
--shared-memory
), LoanedSamples (--zero_copy
)UDP
Analyze the results
After an experiment is run with the -l
flag, a log file is recorded. Both CSV
and JSON formats are supported. It is possible to add custom data to the log
file by setting theAPEX_PERFORMANCE_TEST
environment variable before running
an experiment, e.g.
# JSON format
export APEX_PERFORMANCE_TEST="
{
\"My Version\": \"1.0.4\",
\"My Image Version\": \"5.2\",
\"My OS Version\": \"Ubuntu 16.04\"
}
"
Plot the results
To plot the results in the JSON or CSV log files, see the plotter README.
Architecture
Apex.AI’s Performance Testing in ROS 2 white paper (available here) describes how to design a fair and unbiased performance test, and is the basis for this project.
Each middleware has a different API. Thanks to the Plugin
abstraction, the core logic of
setting up and running an experiment is completely decoupled from the implementation details
of sending and receiving individual messages.
Exactly one Plugin
implementation is selected at build time. The design is similar to the
Abstract Factory pattern.
performance_test
declares, but does not define, a static factory method in the PluginFactory
class. Each middleware provides a definition for this factory method to create a concrete Plugin
implementation, and perf_test
calls this factory method directly.
An example plugin is available here.
Performance optimizations
On linux-based platforms,
perf_test
writes0
to/dev/cpu_dma_latency
and holds open the file handle, which will prevent the CPU from entering any idle states for the duration of the experiment. This should result in lower message latency and lower variance in that latency.
Future extensions and limitations
Communication frameworks like DDS have a huge amount of settings. This tool only allows the most common QOS settings to be configured. The other QOS settings are hardcoded in the application.
Only one publisher per topic is allowed, because the data verification logic does not support matching data to the different publishers.
Some communication plugins can get stuck in their internal loops if too much data is received. Figuring out ways around such issues is one of the goals of this tool.
FastRTPS wait-set does not support timeouts which can lead to the receiving not aborting. In that case the performance test must be manually killed.
Using Connext DDS Micro INTRA transport with
reliable
QoS and history kind set tokeep_all
is not supported with Connext Micro. Setkeep-last
as QoS history kind always when usingreliable
.
Possible additional communication which could be implemented are:
Raw UDP communication
Building with limited resources
When building this tool, the compiler must perform a lot of template expansion. This can be overwhelming for a system with a low-power CPU or limited RAM. There are some additional CMake options which can reduce the system load during compilation:
This tool includes many different message types, each with many different sizes. Reduce the number of messages, and thus the compilation load, by disabling one or more message types. For example, to build without
PointCloud
messages, add-DENABLE_MSGS_POINDCLOUD=OFF
to the--cmake-args
. The message types, and their options for enabling/disabling, can be found here.