Titan-Cassandra graph not (immediately) saved on commit?

Question

I am working with Titan Server (using Cassandra) v0.3.1 on Windows 7 and seeing some inconsistent behavior around writes to the graph. For some reason, new nodes seem to "disappear" after committing a transaction. I'm thinking there is some sort of cache/delayed write involved, but am not sure what Titan is doing under the hood.

Do you have any ideas as to why nodes seem to disappear on commit?

--

Here is a sequence of commands run in the Gremlin shell:

gremlin> g = TitanFactory.open("cassandra.local")
==>titangraph[cassandrathrift:127.0.0.1]

Shows the two nodes I have added to the graph so far:

gremlin> g.V
==>v[280096]
==>v[280100]

Now add a node:

gremlin> g.addVertex()
==>v[360004]

New node appears in graph:

gremlin> g.V
==>v[280096]
==>v[280100]
==>v[360004]

Now, commit transaction:

gremlin> g.commit()
==>null

...and the new node is gone:

gremlin> g.V
==>v[280096]
==>v[280100]

Answer 1

The solution boiled down to a configuration issue. I had modified cassandra.yaml to use windows-formatted filepaths e.g. c:/titan-all-0.3.1/cassandra/data, but it seems that that format confused java/cassandra.

I just restored the original cassandra.yaml file (it's smart enough to figure out that /tmp is c:/tmp) and everything seems to be working fine now.