One graph in one Titan instance

That's something that took me a while to realize, but think is important to keep in mind while travelling to Titan's land.

From the thread is it possible to have multiple graphs in one titan instance? on Titan's users mailing list:

Is it possible to have multiple graphs in one Titan instance?

My goal is to have two graphs - one for production data, and the second one for unit tests. These graphs will be used in PHP application, so I will communicate through the REST api with gremlin queries (since there is no PHP driver for titan afaik).

The response from a Titan developer Stephen was as follows:

if you want two completely separate graphs, then you also have to change the associated configuration in rexster.xml to point at different cassandra/hbase instance or change the storage.keyspace/storage.tablename if using the same cassandra/hbase instances.

Then, Daniel stepped forward and said:

Use a different setting for <storage.keyspace>...</storage.keyspace> and it should work.

Mind, however, that it's for the past version of Titan. It should be storage.cassandra.keyspace for 0.9.0-M1.

And, ultimately Filip - the original poster - confirmed its proper working:

Thanks to both of you, it works now, by specifying the keyspace in the configuration.

From https://groups.google.com/d/msg/aureliusgraphs/96ZJcKmyeXk/JuxLM5DHVwYJ:

Generally speaking the recommendation is that a production graph should have its own cassandra cluster.

And further along the thread:

You can have two disconnected graphs in the same Titan instance.