# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# Copyright 2014 Nextdoor.com, Inc
"""
:mod:`kingpin.actors.aws.settings`
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Common settings used by many of the `kingpin.actors.aws` modules.
"""
import os
import boto
__author__ = 'Mikhail Simin <mikhail@nextdoor.com>'
# By default, this means that Boto will make HTTP calls at instantiation time
# to determine whether or not credentials are available from the metadata
# service.
#
# During tests, we mock these out to blank strings to prevent these calls.
AWS_ACCESS_KEY_ID = os.getenv('AWS_ACCESS_KEY_ID', None)
AWS_SECRET_ACCESS_KEY = os.getenv('AWS_SECRET_ACCESS_KEY', None)
SQS_RETRY_DELAY = 30
ECS_RETRY_ATTEMPTS = 3
ECS_RETRY_DELAY = 5
# Common Settings for the retrying.retry() decorator
#
# Use like this: @retrying.retry(**settings.RETRYING_SETTINGS)
#
[docs]def is_retriable_exception(exception):
"""Return true if this AWS exception is transient and should be retried.
Example:
>>> @retry(retry_on_exception=is_retriable_exception)
"""
retry_codes = (
'Throttling',
'Rate exceeded'
)
# Only handle Boto exceptions
if not isinstance(exception, boto.exception.BotoServerError):
return False
# Boto exceptions should have a code attribute
error_code = exception.error_code or ''
return any([c in error_code for c in retry_codes])
RETRYING_SETTINGS = {
# Verify if we need to retry with the is_retriable_exception
# method described above.
'retry_on_exception': is_retriable_exception,
# Wait up to 10 times
'stop_max_attempt_number': 10,
# Add 250ms of random jitter to every retry
'wait_jitter_max': 250,
# Add 250ms of sleep to every retry
'wait_fixed': 250,
# Now add between 250-2000ms to every retry
'wait_random_min': 250,
'wait_random_max': 2000,
# Finally, add in an exponential backoff timer with a 10s limit
'wait_exponential_multiplier': 100,
'wait_exponential_max': 10000
}