How to install collective.atcassandrastorage
- Download and install ActivePython
- Open Command Prompt
- Type
pypm install collective.atcassandrastorage
Lastest release
Abstract
An Archetype field storage which uses a cassandra backing store.
Reasoning
For a customer project I'm doing right now I'm using cassandra as a storage backend for Plone FormGen data. Now the need did arise to also have specific fields of AT content types to be stored in cassandra as well.
Design decisions
- configuration of the cassandra clients done by using plone.app.registry
- per-field configurable keyspace and column family for fields
- The UID of the instance object is used as a key in the specified
column family (remember that an insert in cassandra is essentially an update)
- using pycassa as glue library
Usage
Import the storage and attach it to a field in your AT Schema:
from collective.atcassandrastorage.storage import CassandraFieldStorage
MySchema = atapi.Schema( ... StringField("afield", storage=CassandraFieldStorage("AKeyspace", "AColumnFamily"), ), ... )
This will store and fetch data for afield from a cassandra database using the keyspace AKeyspace and the column family AColumnFamily.
Configuration
Configuration is done using plone.app.registry. Visit the registry in Plone's control panel and configure the values, they should be pretty much obvious.
Dependencies
plone.app.registry for configuration
pycassa python Cassandra glue library
Links
cassandra http://cassandra.apache.org/
archetypes http://plone.org/products/archetypes
pycassa http://github.com/vomjom/pycassa
Changelog
0.2 (2010-05-31)
- Added tests.
[seletz]
- Introduce IInstanceKey interface to allow to overwrite instance key
calculation. [seletz]
0.1 (2010-05-29)
- Initial release
[seletz]