Cassandra Object

Cassandra Object provides a nice API for working with Cassandra. CassandraObjects are mostly duck-type compatible with ActiveRecord objects so most of your controller code should work ok. Note that they're mostly compatible, Cassandra has no support for dynamic queries, or sorting. So the following kinds of operations aren't supported and never will be.

• :order
• :conditions
• :joins
• :group

There isn't much in the way of documentation yet, but a few examples.

    class Customer < CassandraObject::Base
      attribute :first_name,    :type => :string
      attribute :last_name,     :type => :string
      attribute :date_of_birth, :type => :date
      attribute :signed_up_at,  :type => :time_with_zone

      validate :should_be_cool

      key :uuid

      index :date_of_birth

      association :invoices, :unique=>false, :inverse_of=>:customer

      private

      def should_be_cool
        unless ["Michael", "Anika", "Evan", "James"].include?(first_name)
          errors.add(:first_name, "must be that of a cool person")
        end
      end
    end

    class Invoice < CassandraObject::Base
      attribute :number, :type=>:integer
      attribute :total, :type=>:float
      attribute :gst_number, :type=>:string

      # indexes can have a single entry also.
      index :number, :unique=>true

      # bi-directional associations with read-repair support.
      association :customer, :unique=>true, :inverse_of=>:invoices

      # Read migration support
      migrate 1 do |attrs|
        attrs["total"] ||= rand(2000) / 100.0
      end

      migrate 2 do |attrs|
        attrs["gst_number"] = "66-666-666"
      end

      key :natural, :attributes => :number
    end
    
    @invoice = Invoice.get("12345")
    @invoice.customer.invoices.all.include?(@invoice) # true

FAQ

How do I make this work?

Here are some basic directions:

1. git clone git://github.com/NZKoz/cassandra_object.git
2. Run the bundler gem bundle
3. Make sure the tests pass rake test

This gem has backwards compatibility with active support version 2.3.x, this is to enable people to use it with rails 2.3 applications. This backwards compatibility may not continue after the 1.0 release.

Should I use this in production?

Only if you're looking to help out with the development, there are a bunch of rough edges right now.

Why do you use a superclass and not a module.

Because.

##Development Notes In order to facilitate testing, we have included a vendorised version of cassandra. This must be running with a valid test schema before running the tests

cd vendor/cassandra-0.7/ bin/cassandra bin/cassandra-cli -host localhost --file conf/schema-sample.txt