fluent/fluentd · error · Fluent::InvalidRootDirectory

non directory entry exists:#{root_dir}

Error message

non directory entry exists:#{root_dir}

What it means

Error "non directory entry exists:#{root_dir}" thrown in fluent/fluentd.

Source

Thrown at lib/fluent/supervisor.rb:713

    def run_supervisor(dry_run: false)
      if dry_run
        $log.info "starting fluentd-#{Fluent::VERSION} as dry run mode", ruby: RUBY_VERSION
      end

      if @system_config.workers < 1
        raise Fluent::ConfigError, "invalid number of workers (must be > 0):#{@system_config.workers}"
      end

      if Fluent.windows? && @system_config.with_source_only
        raise Fluent::ConfigError, "with-source-only is not supported on Windows"
      end

      root_dir = @system_config.root_dir
      if root_dir
        if File.exist?(root_dir)
          unless Dir.exist?(root_dir)
            raise Fluent::InvalidRootDirectory, "non directory entry exists:#{root_dir}"
          end
        else
          begin
            FileUtils.mkdir_p(root_dir, mode: @system_config.dir_permission || Fluent::DEFAULT_DIR_PERMISSION)
          rescue => e
            raise Fluent::InvalidRootDirectory, "failed to create root directory:#{root_dir}, #{e.inspect}"
          end
        end
      end

      begin
        ServerEngine::Privilege.change(@chuser, @chgroup)
        MessagePackFactory.init(enable_time_support: @system_config.enable_msgpack_time_support)
        Fluent::Engine.init(@system_config, supervisor_mode: true, start_in_parallel: ENV.key?("FLUENT_RUNNING_IN_PARALLEL_WITH_OLD"))
        Fluent::Engine.run_configure(@conf, dry_run: dry_run)
      rescue Fluent::ConfigError => e
        $log.error 'config error', file: @config_path, error: e
        $log.debug_backtrace

View on GitHub (pinned to dd45c6e18d)

When it happens

Trigger: Thrown at lib/fluent/supervisor.rb:713 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of fluent/fluentd@dd45c6e18d (2026-08-21). Data as JSON: /api/errors/174ff0e04ca76175. Report an issue: GitHub.