Mosca advanced usage

All the types of brokers we can use:

On this section we will list all the pubsubsettings that you can use as mosca brokers (plus the options for each one).

- MongoDB

var pubsubsettings = {
  //using ascoltatore
  type: 'mongo',
  url: 'mongodb://localhost:27017/mqtt',
  pubsubCollection: 'ascoltatori',
  mongo: {}
};

Mongo options:

• url: the mongodb url (default: 'mongodb://localhost:27017/ascoltatori?auto_reconnect')
• pubsubCollection: where to store the messages on mongodb (default: pubsub)
• mongo: settings for the mongodb connection

- Redis

var pubsubsettings = {
  type: 'redis',
  redis: require('redis'),
  db: 12,
  port: 6379,
  return_buffers: true, // to handle binary payloads
  host: "localhost"
};

Redis options:

• port, the optional port to connect to;
• host, the optional host to connect to;
• db, the database to connect to (defaults to 0);
• password, the optional password to use;
• sub_conn, the optional redis connection to use for the sub and psub commands;
• pub_conn, the optional redis connection to use for the pub command;
• redis, the redis module (it will automatically be required if not present).

- Mosquitto (! this uses an existing mqtt broker called mosquitto as the parent broker)

var pubsubsettings = {
  type: 'mqtt',
  json: false,
  mqtt: require('mqtt'),
  host: '127.0.0.1',
  port: 1883
};

Mosquitto options:

• clientId, the id of the MQTT client (max 23 chars)
• keepalive, the keepalive timeout in seconds (see the MQTT spec), the default is 3000;
• port, the port to connect to;
• host, the host to connect to;
• mqtt, the mqtt module (it will automatically be required if not present).

- AMQP (RabbitMQ)

var pubsubsettings = {
  type: 'amqp',
  json: false,
  client: {
     host:'127.0.0.1',
     port: 5672,
     login: 'username',
     password: 'pass'
  },
  amqp: require('amqp'),
  exchange: 'ascolatore5672'
};

Amqp options:

• client, which is passed through to the amq.createConnection method;
• exchange, the exchange name;
• amqp, the amqp module (it will automatically be required if not present);

- QlobberFSQ

You can use any of the QlobberFSQ constructor options, for example:

var pubsubsettings = {
  type: 'zmq',
  json: false,
  zmq: require("zmq"),
  port: "tcp://127.0.0.1:33333",
  controlPort: "tcp://127.0.0.1:33334",
  delay: 10
};

- ZeroMQ

• port, the zmq port where messages will be published;
• controlPort, the zmq port where control messages will be exchanged;
• remotePorts, the remote control ports that will be connected to;
• zmq, the zmq module (it will automatically be required if not present);
• delay, a delay that is applied to the ready and closed events (the default is 5ms);

- Nothing

You could just use NO settings at all and store everything in memory and not in a pub/sub broker

##Further Configuration

A few known events to listen for:

• clientConnected : when a client is connected; the client is passed as a parameter.
• clientDisconnecting : when a client is being disconnected; the client is passed as a parameter.
• clientDisconnected : when a client is disconnected; the client is passed as a parameter.
• published : when a new message is published; the packet and the client are passed as parameters.
• delivered : when a client has sent back a puback for a published message; the packet and the client are passed as parameters.
• subscribed : when a client is subscribed to a topic; the topic and the client are passed as parameters.
• unsubscribed : when a client is unsubscribed to a topic; the topic and the client are passed as parameters.

Other options of mosca (the ones we inserted in our moscaSettings var)

Mosca Options:

• port, the port where to create the server.
• host, the IP address of the server (see http://nodejs.org/api/net.html#net_server_listen_port_host_backlog_callback).
• backend, all the options for creating the Ascoltatore (we pass the pubsubsettings var on this one) that will power this server.
• ascoltatore, By default mosca creates an ascoltatore instance under the hood. With this setting you can pass your own ascoltatore instance. (If you set that theres no need to set the backend)
• maxInflightMessages, the maximum number of inflight messages per client.
• logger, the options for Bunyan. (Example: {level: 'debug'} )
• logger.childOf, the parent Bunyan logger.
• persistence, the options for the persistence. A sub-key factory is used to specify what persistence to use.
• secure, an object that includes three properties:
  • port, the port that will be used to open the secure server
  • keyPath, the path to the key
  • certPath, the path to the certificate
• allowNonSecure, starts both the secure and the unsecure server.
• http, an object that includes the properties:
  • port, the port that will be used to open the http server
  • bundle, serve the bundled mqtt client
  • static, serve a directory
  • stats, publish the stats every 10s (default false).
• https, an object similar to http, instead use secure Websockets connection if secure object is provided.

##Persistence

You can use Mongo, Redis and LevelUp for persistence storage (mostly for the offline messages feature)

Below are the options you can use for persistence.

Mongo persistence options:

• url, the connection URL of the database
• ttl, an object containing two values:
  • subscriptions, the time (ms) after which subscriptions will expire. It defaults to 1 hour.
  • packets, the time (ms) after which packets will expire. It defaults to 1 hour.
• mongo, all the options for the MongoDB driver.
• connection, a MongoDB client to be reused (optional) - thats if you already have a MongoDB client that you use.

Redis persistence options:

• port, the Redis' port.
• host, the Redis' host.
• password, the Redis' password.
• redisOpts, the options for the Redis client.
• channel, the pub/sub channel that will be used to synchronize the various clients. Defaults to 'moscaSync'.
• ttl, an object containing three values:
  • subscriptions, the time (ms) after which subscriptions will expire. It defaults to 1 hour.
  • packets, the time (ms) after which packets will expire.

LevelUp

LevelUp options:

• path, the path to the database
• ttl, an object containing three values:
  • checkFrequency, the frequency at which the the expiration will be checked. It defaults to 1 minute.
  • subscriptions, the time (ms) after which subscriptions will expire. It defaults to 1 hour.
  • packets, the time (ms) after which packets will expire. It defaults to 1 hour.
• db, the AbstractLevelDown implementation.
• all other levelup options.