NewRelic Ruby Agent: errors not ignored

Question

In a Sidekiq worker I want to ignore some errors in NewRelic while still raising them so that Sidekiqs retry behaviour kicks in. I wrote a helper class to call NewRelic::Agent.ignore_transaction but still NewRelic reports these exceptions and complains about the error rate. What am I doing wrong? I guess that I may have misunderstood something about the scope of the transaction?

module NewRelic
  # Run a block which rescues some exceptions and ignores them in NewRelic
  class IgnoreExceptions
    class << self
      def ignore(*class_list)
        raise ArgumentError, 'Block required' unless block_given?
        begin
          yield
        rescue errors_matching { |e| class_list.include?(e.class) }
          NewRelic::Agent.ignore_transaction
          raise
        end
      end

      private

      def errors_matching(&block)
        Module.new.tap { |m| m.define_singleton_method(:===, &block) }
      end
    end
  end
end

Answer 1

Instead of trying to ignore the transaction you may be better off targeting the errors being generated. If there is a specific error class you would like the New Relic Ruby agent to ignore you could utilize the error_collector.ignore_errors configuration option. Another possible solution would be to use the NewRelic::Agent#ignore_error_filter method to filter the errors the agent is tracking.