This groovy script loads the Enron email graph and performs a traversal for the shortest path between two nodes

downloadAndWrite.sh

#!/bin/bash

wget https://snap.stanford.edu/data/email-Enron.txt.gz
gunzip email-Enron.txt.gz
bin/gremlin.sh #and then :load enron.groovy

enron-tinkergraph.groovy

graph = TinkerGraph.open()
graph.createIndex("nodeId", Vertex.class)

vertexMap = new HashMap<Integer, Vertex>();
new File("email-Enron.txt").eachLine { final String line ->
  if(!line.startsWith("#")) {
    g = graph.traversal()
    outin = line.split("\\s+")
    outV = Integer.valueOf(outin[0])
    inV = Integer.valueOf(outin[1])

    if(!vertexMap.containsKey(outV)) {
        vertexMap.put(outV, graph.addVertex(label, 'node', 'nodeId', outV))
    }
    if(!vertexMap.containsKey(inV)) {
        vertexMap.put(inV, graph.addVertex(label, 'node', 'nodeId', inV))
    }

    vertexMap.get(outV).addEdge('similar', vertexMap.get(inV))
  }
}

class DepthPredicate implements java.util.function.Predicate<Traverser<T>> {
    private final int hops;
    public DepthPredicate(int hops) { this.hops = hops; }
    public boolean test(Traverser<T> t) { return t.path().size() <= hops; }
}
d = new DepthPredicate(5)
start = Integer.valueOf(775);
end = Integer.valueOf(990);
//g.V().has("nodeId", start).repeat(out('similar').simplePath()).until(has('nodeId', end).and().filter(d)).limit(1).path().by('nodeId')

enron.groovy

graph = com.thinkaurelius.titan.core.TitanFactory.build().set("storage.backend", "inmemory").
  set("storage.transactions", "false").set("storage.batch-loading", "true").open()
mgmt = ((com.thinkaurelius.titan.graphdb.database.StandardTitanGraph) graph).openManagement()
nodeIdPropKey = mgmt.makePropertyKey("nodeId").dataType(Integer.class).make()
mgmt.buildIndex('byNodeId', org.apache.tinkerpop.gremlin.structure.Vertex.class).addKey(nodeIdPropKey).unique().
  buildCompositeIndex()
mgmt.makeEdgeLabel("similar").make()
mgmt.makeVertexLabel("node").make()
mgmt.commit()
graph.tx().commit()

new File("Email-Enron.txt").eachLine { final String line ->
  if(!line.startsWith("#")) {
    g = graph.traversal()
    outin = line.split("\\s+")
    outV = outin[0]
    inV = outin[1]
    def outVertex = g.V().has("nodeId", outV).tryNext().
                      orElseGet { graph.addVertex(label, 'node', 'nodeId', Integer.valueOf(outV.trim())) }
    def inVertex = g.V().has("nodeId", inV).tryNext().
                      orElseGet { graph.addVertex(label, 'node', 'nodeId', Integer.valueOf(inV.trim())) }
    outVertex.addEdge('similar', inVertex)
  }
}

graph.tx().commit()
g = graph.traversal()
class DepthPredicate implements java.util.function.Predicate<Traverser<T>> {
    private final int hops;
    public DepthPredicate(int hops) { this.hops = hops; }
    public boolean test(Traverser<T> t) { return t.path().size() <= hops; }
}
maxDepth = new DepthPredicate(5)
//gremlin server pegs processor to 100% and JVM image size increases without bound after the matching path is printed
//the console prompt delays very much to come back
g.V().has("nodeId", 775).repeat(out('similar').simplePath()).until(has('nodeId',990).and().filter(maxDepth))).
  limit(1).path().by('nodeId')