FluentdとRedisで簡単なアクセスランキングとアイテム相関レコメンド

recommend_and_ranking.rb

module Fluent
  class RecommendRedis < Output
    Fluent::Plugin.register_output('recommend_and_ranking', self)

    require 'redis'
    REDIS = Redis.new(:host => "192.168.1.126", :port => 6379)

    VIEW_PREFIX     = 'view_' # ユーザごとの閲覧履歴のリスト
    RELATION_PREFIX = 'relation_' # アイテム間の相関値
    ACCESS_COUNTER  = 'access_counter' # アイテムごとのアクセスカウンタ

    def configure(conf)
      super
    end

    def start
      super
    end

    def shutdown
      super
    end

    def emit(tag, es, chain)
      es.each do |time, record|
        uid = record['uid']
        item_code = record['item_code']

        view_key = VIEW_PREFIX + record['uid']

        # 閲覧履歴リストとアイテム相関値の更新
        if REDIS.lrange(view_key, 0, 0) != [item_code] then
          REDIS.lpush(view_key, item_code)
          view_history = REDIS.lrange(view_key, 0, 3).find_all{|r| r != item_code}.uniq.reverse.take(2).reverse
          view_history.each do |old_item_code|
            score = REDIS.zincrby(RELATION_PREFIX + old_item_code, 1, item_code)
            score = REDIS.zincrby(RELATION_PREFIX + item_code, 1, old_item_code)
          end
        end

        # ラインキング用アクセスカウンタのインクリメント
        REDIS.zincrby(ACCESS_COUNTER, 1, item_code)
      end

      chain.next
    end

  end
end