Neo4j Source

[ 1 Description ] [ 2 Configuration ] [ 3 Input ports ] [ 4 Output ports ]

Description

This unit is a Source type unit.

A unit that reads events from a Neo4j database and executes a specified query or queries on them for use in Devo.

When the unit receives the events from the database, it executes the query or queries specified in its properties. The successful results are sent to the init port. When the successful query ends, the event exits through the end port.

Every time a new result record is available, the event leaves through the data output port.

If the evaluation produces an error, the event is sent to the error output port.

Configuration

After dragging this unit into the Flow canvas, double-click it to access its configuration options. The following table describes the configuration options of this unit:

Tab	Field	Description

Tab	Field	Description
General	Name	Enter a name for the unit. It must start with a letter, and cannot contain spaces. Only letters, numbers, and underscores are allowed.
	Description	Enter a description detailing the scope of the unit.
	Query	Expression, written in Cypher, that will determine the behavior of the unit.
	Event time field	The name of the field to be used as event time. The value of the selected field must be either Long or Date data type. If null, the current system time is used.
Connection	Neo4j url	The URL (bolt://ip:port) of the host running the Neo4j database.
	Username	The client name to access Neo4j.
	Password	The password requested to access Neo4j.

Input ports

This unit does not have any input ports.

Output ports

Port	Description

Port	Description
init	Emits an event every time a new query is launched successfully. Generated event will be enriched with 'action' field with 'init' value.
data	Emits an event every time a new result record is available.
error	Emits an event every time there's an error, be it because the query could not be launched, or because there was some problem thereafter. Generated event has field 'action' with value 'error', plus standard error fields.
end	Emits an event every time a query that was launched successfully ends. Generated event has field 'action' with value 'end'.