The vertex that has just been created are not immediately available on mixed index (documented here ).
I'm looking for a way to make sure the vertex is indexed, by waiting the mixed index backend. I think the easiest way is to request the vertex id using direct index query:
graph.indexQuery("myIndex", "v.id:" + vertex.id())
But I didn't find a way to do that. Do you think this feature can be added? Maybe I can make a PR.