The amqp_publish node

Publish data to an amqp-broker exchange. The most popular amqp-broker is RabbitMQ.

Incoming data is converted to JSON before sending.


The amqp correlation-id property will be set to phash2(routing_key + payload) using erlang's phash2 function on every published message:

The erlang documentation on phash2:

Portable hash function that gives the same hash for the same Erlang term regardless of machine architecture and ERTS version.

(phash2 outputs an integer which gets casted to a string to be used as a correlation-id)

The amqp_consume node will use this values to perform deduplication on message receiving.


Note: This node is a sink node and does not output any flow-data, therefore any node connected to it will not receive any data from this node.

Example

|amqp_publish()
.host('127.0.0.1') 
.routing_key('my.routing.key')
.exchange('x_xchange')

Parameters

Parameter Description Default
host( string ) Ip address or hostname of the broker from config
port( integer ) The broker's port 5672 / from config file
user( string ) AMQP user from config file
pass( string ) AMQP password from config file
vhost( string ) vhost to connect to on the broker '/'
routing_key( string ) routing key for the published messages
routing_key_lambda( lambda ) lambda expression producing a routing key for the published messages
routing_key_field( string ) path to a field in the current data-item, who's value should be used as the routing-key
exchange( string ) name of the exchange to publish to
qos( integer ) publish quality, see table below for details 1
persistent( bool ) whether to send the amqp messages with delivery-mode 2 (persistent) false (delivery_mode = 1)
ssl( is_set ) whether to use ssl false (not set)

Qos

Qos description consequences
0 In memory queuing of messages, in case of network issues. Does not use publisher confirm on the channel. Highest throuput.
1 On disc queuing of messages, in case of network issues. Does not use publisher confirm on the channel. Not yet published messages will survive a flow crash. At least once.
2 On disc queue + acknowledgment according to acknowledgement from the amqp broker (publisher confirm). Most safe data delivery. Aims at exactly once semantics.