jameswei/neo4j-elasticsearch

Neo4j Elastic{Search} Integration

Integrates Neo4j change-feed with an ElasticSearch cluster.

Approach

This Neo4j Kernel Extension updates an ElasticSearch instance or cluster with changes in the graph.

A transaction event listener checks changed Nodes against a given label, renders the whole node as json document and indexes all changes in bulk with ES.

Installation

Clone this repository and run mvn install -DskipTests
Copy the jar files in target/dependencies to your Neo4j instance’s plugins folder
Also copy target/neo4j-elasticsearch-2.2-SNAPSHOT.jar to the plugins folder
Modify conf/neo4j.properties accordingly (see the Example section)
Restart Neo4j

Example

Suppose that we keep nodes in our Neo4j instance labeled Person and Place, and that we want to index the values of the first_name and last_name properties of the former and name of the latter in two separate ElasticSearch indices named people and places. For that, we would add the following directives to conf/neo4j.properties:

elasticsearch.host_name=http://localhost:9200
elasticsearch.index_spec=people:Person(first_name,last_name), places:Place(name)

With that in place, Neo4j will now track changes to nodes labeled Person or Place and keep our ES instance running on localhost:9200 in sync.

To perform an initial import, you can force a commit by executing a Cypher query like:

MATCH n:Person
SET n.first_name = n.first_name, n.last_name = n.last_name;

MATCH n:Place
SET n.name = n.name;

Developing

To run the tests, run mvn test. Make sure that an elastic{search} server is running on localhost:9200.

Todo

Support indexing of relationships

jameswei / neo4j-elasticsearch