Integrates Neo4j change-feed with an ElasticSearch cluster.
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.
-
Clone this repository and run
mvn clean install -DskipTests
-
Copy the
jar
files intarget/dependency
to your Neo4j instance’splugins
folder -
Also copy
target/neo4j-elasticsearch-3.0-SNAPSHOT.jar
to theplugins
folder -
Modify
conf/neo4j.conf
accordingly (see the Example section) -
Restart Neo4j
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.conf
:
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.
Suppose that we also want to index all nodes (independent of label or scheme)
in a separate index called all_nodes
, we would add the following directive
below the previous:
elasticsearch.index_all=all_nodes
The first two directives (host_name
and index_spec
) are required. The latter
(index_all
) is optional.
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;
By default, the indexes created will contain fields for the Neo4j ID and Labels, named id
and labels
.
These will be auto-created as searchable fields, but, if you’d prefer they not be included,
simply add one or both of these lines to your conf/neo4j.conf
file.
elasticsearch.include_id_field=false
elasticsearch.include_labels_field=false
To run the tests, run mvn test
. Make sure that an elastic{search} server is running on
localhost:9200
.