gistfile1.rb

module MultiTenantedCacheKeys
  def cache_key
    tenant_database_name + "/" + super
  end
 
  def tenant_database_name
    Apartment::Database.current_database
  end
end

class ActiveRecord::Base
  def self.included(base)
    if respond_to?(:cache_key)
      raise NoMethodError.new("This object does not respond to #cache_key")
    end
  end

  include MultiTenantedCacheKeys
end