The mongo_query node

Experimental.

Since 0.15.2

Read data from MongoDB.

Database, collection and selector (query) can be specified by the user.

The mongo_query node will always output data_batch items at the moment, even if there is only 1 result document.

Note: Faxe is not optimized for heavy batch processing, it is rather designed for massive concurrent stream processing. If you want to process more than a few thousand rows at a time, maybe faxe is not the right tool for your job.

Example

def host = 'localhost'

|mongo_query()
.host(host)
.user('root')
.pass('root')
.database('test')
.collection('inventory')
.query(' {"item": "canvas"} ')
.every(5s)
.as('data')

Every 5 seconds query mongo db on database test and collection inventory for documents, that have "canvas" as their values for the "item" field. Sets root field to 'data'.

def host = 'localhost'

|value_emitter()
.every(7s)

|mongo_query()
.host(host)
.user('root')
.pass('root')
.database('test')
.collection('inventory')
.query(' {"size.h": {"$gt": 16}} ') 

Every time a dataitem arrives at this node, from outside, it will query mongodb for documents that have a
nested h field inside a size object, that has a value greater than 16. The node will query mongodb every 7 seconds, triggered by data coming in from the value_emitter node.

Parameters

Parameter	Description	Default
host ( string )	host name or ip address
port ( integer )		27017
user ( string)	username
pass ( string )	the users password
database ( string )	mongo database name
collection ( string )	mongo collection name in database database
query ( string )	a valid mongo selector as a json string	{}
every ( duration )	read interval	5s
align ( is_set )	whether to align the every parameter	false (not set)
as	set the root path for outputs	undefined