def retry_delay(f):
"""Errback, verifes an op is retryable, and delays the next retry.
"""
# Check that operation is retryable.
if not check_retryable(client, max_time, f.value):
return f
# Give the connection a chance to auto-heal
d = sleep(get_delay(session_timeout))
d.addCallback(retry_inner)
return d
def retry(client, func, *args, **kw):
"""Constructs a retry wrapper around a function that retries invocations.
If the function execution results in an exception due to a transient
connection error, the retry wrapper will reinvoke the operation after
a suitable delay (fractional value of the session timeout).
:param client: A ZookeeperClient instance.
:param func: A callable python object that interacts with
zookeeper, the callable must utilize the same zookeeper
connection as passed in the `client` param. The function
must return a single value (either a deferred or result
value).
"""
retry_started = [time.time()]
retry_error = False
while 1:
try:
value = yield func(*args, **kw)
except Exception, e:
# For clients which aren't connected (session timeout == None)
# we raise the errors to the callers.
session_timeout = client.session_timeout or 0
# The longest we keep retrying is 1.2 * session timeout
max_time = (session_timeout / 1000.0) * 1.2 + retry_started[0]
if not check_retryable(client, max_time, e):
# Check if its a persistent client error, and if so use the cb
# if present to try and reconnect for client errors.
if (check_error(e)
and time.time() > max_time
and callable(client.cb_retry_error)
and not retry_error):
log.debug("Retry error %r on %s @ %s",
e, func.__name__, _args(args))
retry_error = True
yield client.cb_retry_error(e)
retry_started[0] = time.time()
continue
raise
# Give the connection a chance to auto-heal.
yield sleep(get_delay(session_timeout))
log.debug("Retry on %s @ %s", func.__name__, _args(args))
continue
returnValue(value)
