[Python]AWS Lambdaでのリトライ処理(Exponential Backoff)のメモ ref: http://qiita.com/hidesakai/items/bb529c4c29952c41c218

app.py

from chalice import Chalice                                                                                                                    
from datetime import datetime
from retrying import retry
import boto3
from botocore.exceptions import ClientError

app = Chalice(app_name='exponential-backoff')

def retryIfClientError(exception):
    print(datetime.now().strftime("%Y/%m/%d %H:%M:%S"))
    print('retrying...')
    # Falseを返すまで再試行をする
    return isinstance(exception, ClientError)

# retry_on_exception: 特定のException拾うため
# stop_max_attempt_number: 試行回数
# wait_exponential_multiplier: 乗数
@retry(retry_on_exception=retryIfClientError, stop_max_attempt_number=3, wait_exponential_multiplier=1000)
def retryS3Test():
    s3 = boto3.resource('s3')
    client = s3.meta.client
    response = client.get_object(Bucket='mybucket', Key='存在しないかもしれないファイル')

@app.route('/')
def index():
    retryS3Test()

file0.txt

$ pip install retrying

requirements.txt

retrying==1.3.3