Skip to content

Instantly share code, notes, and snippets.

@asimihsan
Created March 31, 2012 16:35
Show Gist options
  • Save asimihsan/2266588 to your computer and use it in GitHub Desktop.
Save asimihsan/2266588 to your computer and use it in GitHub Desktop.
python retry decorator
import pymongo.errors
# Retry decorator with exponential backoff
def retry(tries=5, delay=0.1, backoff=2):
"""Retries a function or method until it returns True.
delay sets the initial delay in seconds, and backoff sets the factor by which
the delay should lengthen after each failure. backoff must be greater than 1,
or else it isn't really a backoff. tries must be at least 0, and delay
greater than 0.
Reference:
http://wiki.python.org/moin/PythonDecoratorLibrary#Retry"""
if backoff <= 1:
raise ValueError("backoff must be greater than 1")
tries = math.floor(tries)
if tries < 0:
raise ValueError("tries must be 0 or greater")
if delay <= 0:
raise ValueError("delay must be greater than 0")
def deco_retry(f):
def f_retry(*args, **kwargs):
mtries, mdelay = tries, delay # make mutable
try:
rv = f(*args, **kwargs) # first attempt
except pymongo.errors.AutoReconnect:
logger.exception("Mongo replication set failure")
rv = False
while mtries > 0:
if rv == True: # Done on success
return True
mtries -= 1 # consume an attempt
time.sleep(mdelay) # wait...
mdelay *= backoff # make future wait longer
try:
rv = f(*args, **kwargs) # Try again
except pymongo.errors.AutoReconnect:
logger.exception("Mongo replication set failure")
rv = False
return False # Ran out of tries :-(
return f_retry # true decorator -> decorated function
return deco_retry # @retry(arg[, ...]) -> true decorator
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment