Neo4j Time To Live Extension

Adds a customizable time-to-live mechanism to Neo4j.

Approach

Uses indexed properties, range searches, and detach delete.

Installation

• Clone this repository and run mvn install

• Also copy target/neo4j-ttl-1.0-SNAPSHOT.jar to the plugins folder

• Modify conf/neo4j.properties accordingly (see the Example section)

• Restart Neo4j

Example

If you configure in conf/neo4j.properties:

ttl.label=Timed
ttl.property=ttl
ttl.schedule=60s

With that in place, Neo4j will now track changes to nodes labeled Timed and expires them after their ttl property is smaller than the current timestamp()

In Essence

// create index for range searches
CREATE INDEX ON :Timed(ttl);

// create time-bound node
CREATE (n:Token:Timed {uid:"38948-3434-33", ttl:timestamp() + 180*1000});

// schedule to run regularly
MATCH (n:Timed) WHERE n.ttl <= timestamp() WITH n LIMIT 10000 DETACH DELETE n RETURN count(*) as c

Todo

• Support expiring of relationships