ros2 network_error ai_generated partial

[WARN] [rmw_fastrtps]: Discovery timed out after 30 seconds, some nodes may not be discovered

ID: ros2/ros2-graph-discovery-delay-large-system

Also available as: JSON · Markdown · 中文

90%Fix Rate

87%Confidence

1Evidence

2024-05-12First Seen

Version Compatibility

Version	Status	Introduced	Deprecated	Notes
ros2:humble	active	—	—	—
ros2:iron	active	—	—	—
rmw_fastrtps_cpp:6.3.0	active	—	—	—
fastdds:2.10.0	active	—	—	—

Root Cause

Fast DDS discovery phase exceeded the default timeout due to a large number of nodes (e.g., >20) on the same network, causing incomplete ROS graph discovery.

generic

中文

Fast DDS 发现阶段因同一网络上节点数量过多（例如 >20）而超过默认超时，导致 ROS 图发现不完整。

Official Documentation

https://fast-dds.docs.eprosima.com/en/latest/fastdds/ros2/discovery_server.html

Workarounds

90% success Use Fast DDS discovery server to reduce network traffic. Create a discovery server: fastdds discovery --server-id 0 Then launch nodes with the server environment: ROS_DISCOVERY_SERVER=127.0.0.1:11811 ros2 run my_package my_node This centralizes discovery and reduces timeout issues.
```
Use Fast DDS discovery server to reduce network traffic. Create a discovery server:
fastdds discovery --server-id 0

Then launch nodes with the server environment:
ROS_DISCOVERY_SERVER=127.0.0.1:11811 ros2 run my_package my_node

This centralizes discovery and reduces timeout issues.
```
80% success Increase the discovery timeout and reduce discovery traffic by setting environment variables: export FASTRTPS_DEFAULT_PROFILES_FILE=/path/to/fastdds_profile.xml In the XML, set: <discovery_config> <leaseDuration>PT60S</leaseDuration> <announcementPeriod>PT5S</announcementPeriod> </discovery_config> Then restart nodes.
```
Increase the discovery timeout and reduce discovery traffic by setting environment variables:
export FASTRTPS_DEFAULT_PROFILES_FILE=/path/to/fastdds_profile.xml

In the XML, set:
<discovery_config>
  <leaseDuration>PT60S</leaseDuration>
  <announcementPeriod>PT5S</announcementPeriod>
</discovery_config>

Then restart nodes.
```

中文步骤

使用 Fast DDS 发现服务器减少网络流量。创建发现服务器：
fastdds discovery --server-id 0

然后使用服务器环境启动节点：
ROS_DISCOVERY_SERVER=127.0.0.1:11811 ros2 run my_package my_node

这集中了发现过程并减少了超时问题。

通过设置环境变量增加发现超时并减少发现流量：
export FASTRTPS_DEFAULT_PROFILES_FILE=/path/to/fastdds_profile.xml

在 XML 中设置：
<discovery_config>
  <leaseDuration>PT60S</leaseDuration>
  <announcementPeriod>PT5S</announcementPeriod>
</discovery_config>

然后重启节点。

Dead Ends

Common approaches that don't work:

Increasing the discovery timeout to 60 seconds via environment variable 70% fail
Merely extending the timeout does not address the underlying scalability issue; discovery may still fail with more nodes.
Restarting all nodes simultaneously 85% fail
Simultaneous startup can cause a discovery storm, making the problem worse.