fubar.config

[
  {lager,    %% Log configurations
    [
      {handlers,
        [
          {lager_file_backend,
            [
              {file, "log/console.log"},
              {level, notice}, {size, 104857600}, {date, "$D0"}, {count, 100},
              {formatter_config, [date," ",time," [",severity,"] ",message," (",pid," ",module,":",line,")\n"]}
            ]
          },
          {lager_file_backend,
            [
              {file, "log/error.log"},
              {level, warning}, {size, 10485760}, {date, "$D0"}, {count, 100},
              {formatter_config, [date," ",time," [",severity,"] ",message," (",pid," ",module,":",line,")\n"]}
            ]
          },
          {lager_file_backend,
            [
              {file, "log/stat.log"},
              {level, '=alert'}, {size, 10485760}, {date, "$D0"}, {count, 100},
              {formatter_config, [date," ",time,",",message,"\n"]}
            ]
          }
        ]
      },
      {async_threshold, 10000},
      {error_logger_hwm, 100},
      {colored, true}
    ]
  },

  {fubar,
    [
      %% fubar_app settings control server socket behavior.
      %% THE SETTINGS IN THIS SECTION CAN'T BE CHANGED AT RUNTIME
      %% WHILE MOST OTHERS CAN BE UNLESS STATED OTHERWISE.
      {fubar_app,
        [
          %% Number of minimum acceptors in acceptor pool. 
          {acceptors, 1024},

          %% Maximum number of connections allowed.
          {max_connections, infinity},
                      
          %% Default socket options.
          %% These are overridden by socket_options in mqtt_protocol settings.
          {options,
            [
              {backlog, 1024}, {reuseaddr, true}, {linger, {false, 0}},
              {send_timeout, 10000},
              {certfile, "priv/ssl/cert.pem"}, {keyfile, "priv/ssl/key.pem"},
              {reuse_sessions, false}, {verify, verify_none}
            ]
          }
        ]
      },

      %% fubar_sysmon sets/clears a node's alarm state.
      {fubar_sysmon,
        [
          % 40% of the total physical memory set as a limit
          {high_watermark, 0.4},

          % System check interval in milliseconds
          {interval, 10000},

          % Start offloading to a node with 20% lower load
          {offloading_threshold, 1.2}
        ]
      },

      %% mqtt_protocol settings control mqtt receiver/parser behavior.
      {mqtt_protocol,
        [
          %% Maximum variable header + payload size per mqtt message.
          {max_packet_size, 4096}, % 4kB

          %% Socket buffers are set small to accept a lot of clients.
          {socket_options, [{recbuf, 4096}, {sndbuf, 4096}]}, % 4kB each

          %% Socket buffers for clients from preset addresses have more bandwidth.
          {acl_socket_options, [{recbuf, 1048576}, {sndbuf, 1048576}]},

          %% Dispatch module handles all the mqtt messages after parsing.
          {dispatch, mqtt_server}
        ]
      },

      %% websocket_protocol settings control websocket receiver/parser behavior.
      {websocket_protocol,
        [
          %% Maximum variable header + payload size per mqtt message.
          {max_packet_size, 4096}, % 4kB

          %% Socket buffers are set small to accept a lot of clients.
          {socket_options, [{recbuf, 4096}, {sndbuf, 4096}]}, % 4kB each

          %% Dispatch module handles all the mqtt messages after parsing.
          {dispatch, mqtt_server}
        ]
      },

      %% mqtt_server settings control mqtt message handler behavior.
      {mqtt_server,
        [
          %% This server's public IP address
          {address, "tcp://127.0.0.1:1883"},

          %% The broker closes the connection if a client doesn't send an mqtt connect within given time.
          {timeout, 10000}, % 3s

          %% mqtt spec states that a client should specify keep-alive value in mqtt connect.
          %% But this broker suggests different keep-alive value in mqtt connack
          %% if the keep-alive value specified by the client is too small or too big.
          %% This is not compliant to mqtt spec but a useful extension.
          %% Set this range wide enough if you don't want the extension.
          {valid_keep_alive, {1800, 3600}}, % 1 min ~ 1h

          %% Module:verify/2 function is used to verify credential in mqtt connect.
          %% Uncomment the line below to enable authentication.
          {auth, mqtt_account},

          %% Alt server (custom load balancing extension) offloading parameters.
          {when_overloaded, drop}
        ]
      },

      %% mqtt_session settings control mqtt session behavior.
      {mqtt_session,
        [
          %% Offline sessions are expired after some time.
          {max_age, 172800000}, % 2 days

          %% Maximum transactions waiting for execution.
          {max_wait, 10},

          %% It drops transactions that are not complete within given time.
          {transaction_timeout, 60000}, % 1 min

          %% It stores mqtt messages for temporarily offline clients.
          %% But the number of offline messages are limited.
          {buffer_limit, 3},

          %% It sends duplicate mqtt messages to a client for higher qos.
          %% Retry interval and maximum number of retries are set in prior.
          {max_retries, 5},
          {retry_after, 10000}
        ]
      },

      %% mqtt_topic settings.
      {mqtt_topic, []},

      %% mqtt_client settings to be applied by default.
      {mqtt_client,
        [
          %% mqtt broker ip address
          {host, "127.0.0.1"},

          %% mqtt broker port
          {port, 1883},

          %% mqtt transport protocol
          {transport, ranch_tcp},

          %% mqtt credential
          {username, <<"">>},
          {password, <<"">>},

          %% Default handler
          {handler, mqtt_client_simple}
        ]
      },

      %% Real world simulation parameters.
      %% Applies to mqtt_client_killer:start/1, mqtt_client_monitor:start/1
      {mqtt_client_killer,
        [
          %% mean reconnection interval
          {mri, 1800}
        ]
      },

      {mqtt_client_monitor,
        [
          %% max clients per second
          {max_cps, 10},

          %% client id range
          {range, {1, 100}},

          %% client specification
          {mfa, {mqtt_client, start, [[]]}}
        ]
      }
    ]
  }
].