# # Persist DynaModel records for a particular model to S3 for extra backup. # # The DynamoDB backup model (using EMR to read and write to S3 is not incremental and quickly takes way too long # and defeats the purpose of a backup) # # This is not intended to be used for models with high frequency writes but as a way to incrementally backup models # that contain mission critical data (although S3 backups are not guarenteed to be durable since you probably want to delay # the S3 write to a backround task). # module DynaModel module Extensions module S3Backup extend ActiveSupport::Concern included do after_save :backup_dyna_model_record_to_s3 end def backup_dyna_model_record_to_s3 if self.class.dyna_model_s3_backup_config if self.class.dyna_model_s3_backup_config[:after_save] self.class.dyna_model_s3_backup_config[:after_save].call(self) else self.write_dyna_model_s3_backup! end end end def write_dyna_model_s3_backup! self.class.dyna_model_s3_backup_bucket.objects[File.join(self.class.dyna_model_s3_backup_config[:prefix], "#{self.guid}.json")].write(self.to_dyna_model_s3_backup_json) end def to_dyna_model_s3_backup_json ActiveSupport::JSON.encode({ class: self.class.to_s, attributes: self.attributes }) end module ClassMethods def dyna_model_s3_backup(options={}) raise "DynaModel::Extensions::S3Backup requires a bucket." unless options[:bucket] options[:prefix] ||= "#{self.to_s.underscore.pluralize}-#{Rails.env}" #options[:after_save] = lambda { |obj| ... } @@dyna_model_s3_backup_config = options end def dyna_model_s3_backup_client @@dyna_model_s3_backup_client ||= AWS::S3.new end def dyna_model_s3_backup_config @@dyna_model_s3_backup_config end def dyna_model_s3_backup_bucket self.dyna_model_s3_backup_client.buckets[self.dyna_model_s3_backup_config[:bucket]] end def enable_dyna_model_s3_backup_versioning! self.dyna_model_s3_backup_bucket.enable_versioning end def suspend_dyna_model_s3_backup_versioning! self.dyna_model_s3_backup_bucket.suspend_versioning end def create_dyna_model_s3_backup_bucket! self.dyna_model_s3_backup_client.buckets.create(self.dyna_model_s3_backup_config[:bucket]) end # Helper for sidekiq/etc delay method on class def dyna_model_s3_backup_object(guid) self.read_guid(guid).try(:write_dyna_model_s3_backup!) end # TODO: improve for high scale... ability to resume def import_from_dyna_model_s3_backup self.dyna_model_s3_backup_bucket.objects.with_prefix(self.dyna_model_s3_backup_config[:prefix]).each_batch do |batch| batch.each do |item| puts "Found #{item.key}" obj_json = ActiveSupport::JSON.decode(item.read) obj = obj_json["class"].constantize.new obj.attributes = obj_json["attributes"] if obj.save puts "Saved #{obj.guid}." else puts "Failed to save #{obj.guid}. #{obj.errors.full_messages.to_sentence}" end end end end end end end end