caped_collection.rb

require 'mongo'

VIEW_PRODUCT=0
ADD_TO_CART =1
CHECKOUT    =2
PURCHASE    =3

@con = Mongo::Connection.new
@db  = @con['garden']

@db.drop_collection("user.actions")
@db.create_collection("user.actions", capped: true, size: 1024)

@actions = @db['user.actions']
40.times do |n|
  doc = {
    username: "kbanker",
    action_code: rand(4),
    time: Time.now.utc,
    n: n
  }

  @actions.insert(doc)
end