Tornado Async Client for CouchDB
tor-async-couchdb is an opinionated Tornado async client for CouchDB. tor-async-couchdb is intended to operate as part of a service’s application tier and interact with the service’s data tier implemented using CouchDB.
tor-async-couchdb documentation isn’t as strong as it could be. sample services are best way to gain an understanding of how to use tor-async-couchdb.
tor-async-couchdb was created as a way to capture a very opinionated set of best practices and learnings after operating and scaling a number of services that used CouchDB and Tornado. The bullets below summarize the opinions.
services should embrace eventual consistency
thoughts on data models:
every document should have a versioned type property (ex type=v9.99)
documents are chunky aka retrieval of a single document should typically be all that’s necessary to implement a RESTful service’s endpoint ala standard NoSQL data model thinking
assume conflicts happen as part of regular operation
sensitive data at rest is an information security concern that must be addressed
each property should be evaluated against a data and information classification policy
this is a good example of data classification policy
if a sensitive proprerty can’t be hashed it should be encrypted using Keyczar
direct tampering of data in the database is undesirable and therefore tamper resistance is both valued and a necessity
to prevent unncessary fragmentation, CouchDB, not the service tier, should generate document IDs
document retrieval should be done through views against document properties not document IDs
one design document per view
horizontally scaling CouchDB should be done using infrastructure (CouchDB 2.0 or Cloudant) not application level sharding
>pip install tor_async_couchdb
Configure tor-async-couchdb in your service’s mainline. Typically the configuration options are expected to come from a configuration file and/or the service’s command line.
from tor_async_couchdb import async_model_actions async_model_actions.database = "http://127.0.0.1:5984/database" async_model_actions.tampering_signer = None async_model_actions.username = None async_model_actions.password = None async_model_actions.validate_cert = True
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