wehub-resource-sync
ec2b666284
Continuous Integration / Pre-commit Linter (push) Has been cancelled
Continuous Integration / Mypy Check (Python 3.10) (push) Has been cancelled
Continuous Integration / Mypy Check (Python 3.11) (push) Has been cancelled
Continuous Integration / Mypy Check (Python 3.12) (push) Has been cancelled
Continuous Integration / Mypy Check (Python 3.13) (push) Has been cancelled
Continuous Integration / Unit Tests (Python 3.10) (push) Has been cancelled
Continuous Integration / Unit Tests (Python 3.11) (push) Has been cancelled
Continuous Integration / Unit Tests (Python 3.12) (push) Has been cancelled
Continuous Integration / Unit Tests (Python 3.13) (push) Has been cancelled
Continuous Integration / Unit Tests (Python 3.14) (push) Has been cancelled
Continuous Integration / A2A v0.3 Tests (Python 3.10) (push) Has been cancelled
Continuous Integration / A2A v0.3 Tests (Python 3.11) (push) Has been cancelled
Continuous Integration / A2A v0.3 Tests (Python 3.12) (push) Has been cancelled
Copybara PR Handler / close-imported-pr (push) Has been cancelled
Continuous Integration / A2A v0.3 Tests (Python 3.13) (push) Has been cancelled
Continuous Integration / A2A v0.3 Tests (Python 3.14) (push) Has been cancelled
44 lines
2.2 KiB
Markdown
44 lines
2.2 KiB
Markdown
# ADK Workflow Sample: Node Retries
|
|
|
|
## Overview
|
|
|
|
In real-world applications, interacting with external APIs, databases, or third-party services can occasionally result in transient failures (e.g., temporary network outages, rate limits, or bad gateways).
|
|
|
|
The ADK framework allows you to easily handle these scenarios by wrapping the unreliable logic in a `@node` decorator configured with `RetryConfig`. If the node raises one of the expected exceptions, the workflow engine automatically pauses, waits for a backoff delay, and reschedules the node for another attempt.
|
|
|
|
When a node raises an exception, the framework automatically emits an error event (with `error_code` and `error_message`) so the error is visible in the event stream. If the node has retry configured, it will be retried after the backoff delay.
|
|
|
|
This sample demonstrates a `get_weather` node that intentionally fails randomly (70% chance) by raising an `HTTPError` representing a 500 Internal Server error. The framework gracefully recovers and eventually succeeds, passing the result to `report_weather`.
|
|
|
|
## Graph
|
|
|
|
```mermaid
|
|
graph TD
|
|
START --> get_weather[get_weather <br/>Retries on HTTPError]
|
|
get_weather --> report_weather
|
|
```
|
|
|
|
## How To
|
|
|
|
1. **Import `RetryConfig`**: Ensure you import the configuration class to set your retry parameters.
|
|
|
|
```python
|
|
from google.adk.workflow import RetryConfig
|
|
```
|
|
|
|
1. **Configure the Decorator**: Apply the `@node` decorator to your Python function and specify the `retry_config` parameter with your desired logic (e.g., `max_attempts`, `initial_delay`).
|
|
|
|
```python
|
|
@node(retry_config=RetryConfig(max_attempts=5, initial_delay=1))
|
|
def get_weather(ctx: Context) -> str:
|
|
# ... flaky logic here ...
|
|
```
|
|
|
|
When an exception like `HTTPError` occurs, the ADK framework catches it, emits an error event, and processes the backoff delay automatically. As long as `max_attempts` hasn't been exceeded, the node executes again.
|
|
|
|
1. **Track Retries (Optional)**: If you need to know which attempt the node is currently running, you can access `ctx.attempt_count` from the `Context`.
|
|
|
|
```python
|
|
yield Event(message=f"Getting weather... attempt {ctx.attempt_count}")
|
|
```
|