Document how to catch a ProvisionedThroughputExceededException

The documentation makes explicit references to a ProvisionedThroughputExceededException:

If a PutRecord request cannot be processed because of insufficient provisioned throughput on the shard involved in the request, PutRecord throws ProvisionedThroughputExceededException .

The link is broken, and there’s no information on how to catch this exception. Furthermore, grepping the source code for boto3 and botocore only turns up documentation references to ProvisionedThroughputExceededException, no actual implementations of it, so I’m unsure what to import to try and catch/handle this exception.

[ademidun]

This gist might be useful. h/t @shentonfreude

from botocore.exceptions import ClientError

RETRY_EXCEPTIONS = ('ProvisionedThroughputExceededException',
                    'ThrottlingException')
retries=0
while True:
    try:
        res = table.scan(**scan_kw)
        popular.extend(res['Items'])
        last_key = res.get('LastEvaluatedKey')
        print('len={} res[Count]={} last_key={}'.format(
            len(popular), res['Count'], last_key))
        if not last_key:
            break
        retries = 0          # if successful, reset count
        scan_kw.update({'ExclusiveStartKey': last_key})
    except ClientError as err:
        if err.response['Error']['Code'] not in RETRY_EXCEPTIONS:
            raise
        print('WHOA, too fast, slow it down retries={}'.format(retries))
        sleep(2 ** retries)
        retries += 1     # TODO max limit

[alexwlchan]

If I could reliably reproduce this, I could just print out the properties of a ClientError and figure out how to check it for a ProvisionedThroughputExceededException, but it’s not really trivial to reproduce this error.

I was able to reproduce this by flooding a table with capacity=1 with write requests and capturing the error object. For future reference, here are what I think are likely the interesting bits:

import pprint
import random

import boto3

dynamodb = boto3.resource('dynamodb')
table = dynamodb.Table('test__alex')
while True:
    try:
        table.put_item(Item={'ID': str(random.randint(1, 100000)), 'name': open('/usr/share/dict/words').read(2048)})
    except Exception as e:
        f = e
        break

error = f
for attr in dir(f):
    if attr.startswith('_'):
        continue
    print(attr)
    pprint.pprint(getattr(f, attr))
    print()

MSG_TEMPLATE
('An error occurred ({error_code}) when calling the {operation_name} '
 'operation{retry_info}: {error_message}')

args
('An error occurred (ProvisionedThroughputExceededException) when calling the '
 'PutItem operation (reached max retries: 9): The level of configured '
 'provisioned throughput for the table was exceeded. Consider increasing your '
 'provisioning level with the UpdateTable API.',)

operation_name
'PutItem'

response
{'Error': {'Code': 'ProvisionedThroughputExceededException',
           'Message': 'The level of configured provisioned throughput for the '
                      'table was exceeded. Consider increasing your '
                      'provisioning level with the UpdateTable API.'},
 'ResponseMetadata': {'HTTPHeaders': {'connection': 'keep-alive',
                                      'content-length': '241',
                                      'content-type': 'application/x-amz-json-1.0',
                                      'date': 'Tue, 22 Aug 2017 10:04:59 GMT',
                                      'server': 'Server',
                                      'x-amz-crc32': '1545824508',
                                      'x-amzn-requestid': 'CDRKT1L3H717RM1CL61P5J1L63VV4KQNSO5AEMVJF66Q9ASUAAJG'},
                      'HTTPStatusCode': 400,
                      'MaxAttemptsReached': True,
                      'RequestId': 'CDRKT1L3H717RM1CL61P5J1L63VV4KQNSO5AEMVJF66Q9ASUAAJG',
                      'RetryAttempts': 9}}

with_traceback
<built-in method with_traceback of ProvisionedThroughputExceededException object at 0x10f72b588>