/rmw_cyclonedds

ROS 2 RMW layer for Eclipse Cyclone DDS

Primary LanguageC++Apache License 2.0Apache-2.0

ROS 2 RMW for Eclipse Cyclone DDS

Easy, fast, reliable, small Eclipse Cyclone DDS middleware for ROS 2. Make your 🐢 run like a 🚀 Eclipse Cyclone DDS has great adopters and contributors in the ROS community and is an Eclipse Foundation open source project of Eclipse IoT and OpenADx (autonomous driving).

This package lets ROS 2 use Eclipse Cyclone DDS as the underlying DDS implementation. Cyclone DDS is ready to use. It seeks to give the fastest, easiest, and most robust ROS 2 experience. Let the Cyclone blow you away!

  1. Install:

    apt install ros-eloquent-rmw-cyclonedds-cpp

    or

    apt install ros-dashing-rmw-cyclonedds-cpp

  2. Set env variable and run ROS 2 apps as usual:

    export RMW_IMPLEMENTATION=rmw_cyclonedds_cpp

  3. Confirm RMW: In Eloquent and later, to confirm which RMW you're using:

    ros2 doctor --report

Performance recommendations

With large samples (100s of kilobytes), excessive latency can be caused by running out of space in the OS-level receive buffer. For this reason, on Linux, we recommend increasing the buffer size:

  • Temporarily (until reboot): sudo sysctl -w net.core.rmem_max=8388608 net.core.rmem_default=8388608
  • Permanently: echo "net.core.rmem_max=8388608\nnet.core.rmem_default=8388608\n" | sudo tee /etc/sysctl.d/60-cyclonedds.conf

Debugging

So Cyclone isn't playing nice or not giving you the performance you had hoped for? That's not good... Please file an issue against this repository!

The ddsperf tool distributed with Cyclone DDS can be used to check that communication works without ROS. Run ddsperf sanity on two different machines - if the "mean" value is above 100000us, there are likely network issues.

If you're having trouble with nodes discovering others or can't use multicast at all on your network setup, you can circumvent discovery:

export CYCLONEDDS_URI='<Discovery><Peers><Peer Address='myroshost.local' /><Peer Address='myroshost2.local' /></></>'

Here are some ways to generate additional debugging info that can help identify the problem faster, and are helpful on an issue ticket:

  • Configure Cyclone to create richer debugging output:

    • To see the output live:

      export CYCLONEDDS_URI='<Tracing><Verbosity>trace</><Out>stderr</></>'

    • To send to /var/log/:

      export CYCLONEDDS_URI='<Tracing><Verbosity>trace</><Out>/var/log/cyclonedds.${CYCLONEDDS_PID}.log</></>'

  • Create a Wireshark capture:

    wireshark -k -w wireshark.pcap.gz

Building from source and contributing

The following branches are actively maintained:

  • master, which targets the upcoming ROS version, Foxy.
  • dashing-eloquent, which maintains compatibility with ROS releases Dashing and Eloquent

If building ROS 2 from source (ros2.repos), you already have this package and Cyclone DDS:

cd /opt/ros/master
rosdep install --from src -i
colcon build
export RMW_IMPLEMENTATION=rmw_cyclonedds_cpp