fluent/fluentd · error · Fluent::ConfigError

both 'send_keepalive_packet' and 'deny_keepalive' cannot be

Error message

both 'send_keepalive_packet' and 'deny_keepalive' cannot be set to true

What it means

Error "both 'send_keepalive_packet' and 'deny_keepalive' cannot be set to true" thrown in fluent/fluentd.

Source

Thrown at lib/fluent/plugin/in_forward.rb:165

            rescue SocketError
              raise Fluent::ConfigError, "host '#{client.host}' cannot be resolved"
            end
          end
          source_addr = begin
                          IPAddr.new(source || client.network)
                        rescue ArgumentError
                          raise Fluent::ConfigError, "network '#{client.network}' address format is invalid"
                        end
          @nodes.push({
              address: source_addr,
              shared_key: (client.shared_key || @security.shared_key),
              users: client.users
            })
        end
      end

      if @send_keepalive_packet && @deny_keepalive
        raise Fluent::ConfigError, "both 'send_keepalive_packet' and 'deny_keepalive' cannot be set to true"
      end
    end

    def multi_workers_ready?
      true
    end

    HEARTBEAT_UDP_PAYLOAD = "\0"

    def start
      super

      shared_socket = system_config.workers > 1

      log.info "listening port", port: @port, bind: @bind
      server_create_connection(
        :in_forward_server, @port,
        bind: @bind,

View on GitHub (pinned to dd45c6e18d)

When it happens

Trigger: Thrown at lib/fluent/plugin/in_forward.rb:165 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/a59f86f557f346cf. Report an issue: GitHub.