Presentation

DynamoDB is a minimalistic NoSQL engine provided by Amazon as a part of their AWS product.

DynamoDB allows you to store documents composed of unicode, number or binary data as well are sets. Each tables must define a hash_key and may define a range_key. All other fields are optional.

DynamoDB is really awesome but is terribly slooooow with managment tasks. This makes it completly unusable in test environements.

ddbmock brings a nice, tiny, in-memory or sqlite implementation of DynamoDB along with much better and detailed error messages. Among its niceties, it features a double entry point:

• regular network based entry-point with 1:1 correspondance with stock DynamoDB

• embeded entry-point with seamless boto intergration 1, ideal to avoid spinning yet another server.

ddbmock is not intended for production use. It will lose your data. you’ve been warned! I currently recommend the “boto extension” mode for unit-tests and the “server” mode for functional tests.

Installation

$ pip install ddbmock

Developing

$ hg clone ssh://hg@bitbucket.org/Ludia/dynamodb-mock
$ pip install nose nosexcover coverage mock webtest boto
$ python setup.py develop
$ nosetests # --no-skip to run boto integration tests too

What is ddbmock not useful for ?

Do not use it in production or as a cheap DynamoDB replacement. I’ll never stress it enough.

All the focus was on simplicity/hackability and simulation quality. Nothing else.

What is ddbmock useful for ?

• FAST and RELIABLE unit testing

• FAST and RELIABLE functional testing

• experiment with DynamoDB API.

• RELIABLE throughput planification

• RELIABLE disk space planification

• almost any DynamoDB simulation !

ddbmock can also persist your data in SQLITE. This open another vast range of possibilities :)

Current status

• pass all boto integration tests

• support full table life-cycle

• support full item life-cycle

• support for all item limitations

• accurate size, throughput reporting

• no limits on concurent table operations

• no limits for request/response size nor item count in these

See http://ddbmock.readthedocs.org/en/latest/pages/status.html for detailed up-to-date status.

History

• v1.0.0 (*): full documentation and bugfixes

• v0.4.1: schema persistence + thread safety, bugfixes

• v0.4.0: sqlite backend + throughput statistics + refactoring, more documentation, more tests

• v0.3.2: batchWriteItem support + pass boto integration tests

• v0.3.1: accuracy in item/table sizes + full test coverage

• v0.3.0: first public release. Full table lifecycle + most items operations

(?) indicates a future release. These are only ideas or “nice to have”.

Example usage

$ pserve development.ini # launch the server on 0.0.0.0:6543

import boto
from ddbmock import connect_boto_network

# Use the provided helper to connect your *own* endpoint
db = connect_boto_network()

# Done ! just use it wherever in your project as usual.
db.list_tables() # get list of tables (empty at this stage)

def connect_boto_network(host='localhost', port=6543):
    import boto
    from boto.regioninfo import RegionInfo
    endpoint = '{}:{}'.format(host, port)
    region = RegionInfo(name='ddbmock', endpoint=endpoint)
    return boto.connect_dynamodb(region=region, port=port, is_secure=False)

import boto
from ddbmock import connect_boto_patch

# Wire-up boto and ddbmock together
db = connect_boto_patch()

# Done ! just use it wherever in your project as usual.
db.list_tables() # get list of tables (empty at this stage)

Requirements

• Python 2.7.x

• Pyramid >= 1.3

• Boto >= 2.5.0 (optional)

• NO AWS account :)

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