JanusGraph

    Start a cluster on your local machine. Check that you are able to connect to YugabyteDB using by doing the following.

    1. Connected to local cluster at 127.0.0.1:9042.
    2. [cqlsh 5.0.1 | Cassandra 3.9-SNAPSHOT | CQL spec 3.4.2 | Native protocol v4]
    3. Use HELP for help.
    4. cqlsh> DESCRIBE KEYSPACES;
    6. system_schema  system_auth  system
    8. cqlsh>

    2. Download JanusGraph

    1. $ wget https://github.com/JanusGraph/janusgraph/releases/download/v0.2.0/janusgraph-0.2.0-hadoop2.zip
    2. $ unzip janusgraph-0.2.0-hadoop2.zip
    3. $ cd janusgraph-0.2.0-hadoop2
    • Start the Gremlin console by running ./bin/gremlin.sh. You should see something like the following.
    1. $ ./bin/gremlin.sh
    2.      \,,,/
    3.      (o o)
    4. -----oOOo-(3)-oOOo-----
    5. plugin activated: janusgraph.imports
    6. plugin activated: tinkerpop.server
    7. plugin activated: tinkerpop.utilities
    8. plugin activated: tinkerpop.spark
    9. plugin activated: tinkerpop.tinkergraph
    • Now use the CQL config to initialize JanusGraph to talk to Yugabyte.
    • Open the YugabyteDB UI to verify that the janusgraph keyspace and the necessary tables were created by opening the following URL in a web browser: http://localhost:7000/ (replace localhost with the ip address of any master node in a remote depoyment). You should see the following.

    4. Load sample data

    1. gremlin> GraphOfTheGodsFactory.loadWithoutMixedIndex(graph,true)
    2. ==>null
    3. gremlin> g = graph.traversal()
    4. ==>graphtraversalsource[standardjanusgraph[cql:[127.0.0.1]], standard]

    For reference, here is the graph data loaded by the Graph of the Gods. You can find a lot more useful information about this in the JanusGraph getting started page.

    • Retrieve the Saturn vertex
    1. gremlin> saturn = g.V().has('name', 'saturn').next()
    2. ==>v[4168]
    • Who is Saturn’s grandchild?
    1. gremlin> g.V(saturn).in('father').in('father').values('name')
    2. ==>hercules
    • Queries about Hercules

    6. Complex graph traversal examples

    • Who are Pluto’s cohabitants?
    1. gremlin> pluto = g.V().has('name', 'pluto').next()
    2. ==>v[8416]
    4. // who are pluto's cohabitants?
    5. gremlin> g.V(pluto).out('lives').in('lives').values('name')
    6. ==>pluto
    7. ==>cerberus
    9. // pluto can't be his own cohabitant
    10. ==>cerberus
    11. gremlin> g.V(pluto).as('x').out('lives').in('lives').where(neq('x')).values('name')
    13. gremlin>
    • Queries about Pluto’s Brothers.
    1. // where do pluto's brothers live?
    2. gremlin> g.V(pluto).out('brother').out('lives').values('name')
    3. ==>sea
    4. ==>sky
    6. // which brother lives in which place?
    7. gremlin> g.V(pluto).out('brother').as('god').out('lives').as('place').select('god', 'place')
    8. ==>[god:v[4248],place:v[4320]]
    9. ==>[god:v[8240],place:v[4144]]
    11. // what is the name of the brother and the name of the place?
    12. gremlin> g.V(pluto).out('brother').as('god').out('lives').as('place').select('god', 'place').by('name')
    13. ==>[god:neptune,place:sea]
    14. ==>[god:jupiter,place:sky]

    Geo-spatial indexes - events that have happened within 50 kilometers of Athens (latitude:37.97 and long:23.72).

    1. // Show all events that happened within 50 kilometers of Athens (latitude:37.97 and long:23.72).
    2. gremlin> g.E().has('place', geoWithin(Geoshape.circle(37.97, 23.72, 50)))
    3. ==>e[4cj-36g-7x1-6c8][4120-battled->8216]
    4. ==>e[3yb-36g-7x1-9io][4120-battled->12336]
    6. // For these events that happened within 50 kilometers of Athens, show who battled whom.
    7. gremlin> g.E().has('place', geoWithin(Geoshape.circle(37.97, 23.72, 50))).as('source').inV().as('god2').select('source').outV().as('god1').select('god1', 'god2').by('name')