RunnableRetry

Retry a Runnable if it fails.

RunnableRetry can be used to add retry logic to any object that subclasses the base Runnable.

Such retries are especially useful for network calls that may fail due to transient errors.

The RunnableRetry is implemented as a RunnableBinding. The easiest way to use it is through the .with_retry() method on all Runnables.

Example: Here's an example that uses a RunnableLambda to raise an exception

import time

def foo(input) -> None:
    '''Fake function that raises an exception.'''
    raise ValueError(f"Invoking foo failed. At time {time.time()}")

runnable = RunnableLambda(foo)

runnable_with_retries = runnable.with_retry(
    retry_if_exception_type=(ValueError,),  # Retry only on ValueError
    wait_exponential_jitter=True,  # Add jitter to the exponential backoff
    stop_after_attempt=2,  # Try twice
    exponential_jitter_params={"initial": 2},  # if desired, customize backoff
)

# The method invocation above is equivalent to the longer form below:

runnable_with_retries = RunnableRetry(
    bound=runnable,
    retry_exception_types=(ValueError,),
    max_attempt_number=2,
    wait_exponential_jitter=True,
    exponential_jitter_params={"initial": 2},
)

This logic can be used to retry any Runnable, including a chain of Runnables, but in general it's best practice to keep the scope of the retry as small as possible. For example, if you have a chain of Runnables, you should only retry the Runnable that is likely to fail, not the entire chain.