produtil.retry Namespace Reference

Contains retry_io() which automates retrying operations. More...

Detailed Description

Contains retry_io() which automates retrying operations.

Functions
def	retry_io
	This function automates retrying an unreliable operation several times until it succeeds. More...

Variables
list	__all__ = ['retry_io']
	Symbols exported by "from produtil.retry import *".

Function Documentation

def produtil.retry.retry_io	(		max_tries,
			sleep_time,
			operation,
			opargs = [],
			logger = None,
			fail = None,
			failargs = [],
			giveup = None,
			giveupargs = [],
			randsleep = True,
			backoff = 1.3,
			first_warn = 0,
			giveup_quiet = False
	)

This function automates retrying an unreliable operation several times until it succeeds.

This subroutine will retry the operation up to a maximum number of times. If the operation fails too many times, then the last exception thrown by the operation is passed on (raised) to the caller.

Parameters

max_tries	Maximum number of times to attempt the operation (mandatory)
sleep_time	Time to sleep between tries
operation	A function or callable object that may thrown an Exception
opargs	A list containing arguments to the operation
logger	A logging.Logger object to use for logging, or None to disable logging.
fail	A string to print, or a function to call, when the operation fails but more retries are possible
failargs	Optional: a list of arguments to fail, or None to disable
giveup	A string to print, or a function to call when the operation fails too many times, causing retry_io to give up. Default: same as fail
giveupargs	Optional: a list of arguments to giveup, or None to disable
randsleep	Set to True (default) to enable an exponential backoff algorithm, which will increase the sleep time between tries
backoff	The exponent for the exponential backoff algorithm
first_warn	The first failure at which to warn via the logger
giveup_quiet	If True, a WARNING-level message is sent to the logger if the operation fails more than max_tries times.

Returns

The return value of the operation.

Note

If fail or giveup are functions, they are passed the contents of failargs (default: opargs) or giveupargs (default: failargs or opargs) with several additional arguments appended. Those arguments are the exception that was caught, the number of attempts so far, the max_tries, the sleep_time, and then a boolean that is true iff the operation is about to be retried.

Definition at line 13 of file retry.py.