ros2 communication_error ai_generated true

rclpy.service.ServiceException: Service /my_service is not available

ID: ros2/service-not-available

Also available as: JSON · Markdown
85%Fix Rate
88%Confidence
3Evidence
2023-01-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
2 active — — —

Root Cause

Service server is not running or registered under a different name. wait_for_service() times out.

generic

Workarounds

  1. 92% success Verify the service server node is running and the name matches exactly 
    ros2 service list | grep my_service
  2. 88% success Check namespace: service name may be under a namespace prefix 
    ros2 service list  # look for /namespace/my_service
  3. 85% success Use wait_for_service with a reasonable timeout and informative error 
    if not client.wait_for_service(timeout_sec=5.0): raise RuntimeError('Service not found')

Dead Ends

Common approaches that don't work:

  1. Increase the timeout to very large values 78% fail

    If the server is not running at all, no amount of waiting will help; masks the real problem

  2. Call the service without waiting, catching exceptions 72% fail

    The call itself will fail with a cryptic error; try/except hides configuration bugs

  3. Use topics instead of services for request/reply 80% fail

    Loses the synchronous call guarantee and requires manual correlation of responses

Error Chain

Preceded by: